Showing posts with label and. Show all posts
Showing posts with label and. Show all posts
Thursday, November 13, 2014
Latest Step Up Booster Powers Eight White LEDs Diagram Circuit
Tiny white LEDs are capable of delivering ample white light without the fragility problems and costs associated with fluorescent backlights. They do pose a problem however in that their forward voltage can be as high as 4 V, precluding them being from powered directly from a single Li-Ion cell. Applications requiring more white LEDs or higher efficiency can use an LT1615 boost converter to drive a series connected array of LEDs. The high efficiency circuit (about 80%) shown here can provide a constant-current drive for up to eight LEDs. Driving eight white LEDs in series requires at least 29 V at the output and this is possible thanks to the internal 36-V, 350-mA switch in the LT1615.
The constant-current design of the circuit guarantees a steady current through all LEDs, regardless of the forward voltage differences between them. Although this circuit was designed to operate from a single Li-Ion battery (2.5V to 4.5V), the LT1615 is also capable of operating from inputs as low as 1 V with relevant output power reductions. The Motorola MBR0520 surface mount Schottky diode (0.5 A 20 V) is a good choice for D1 if the output voltage does not exceed 20 V. In this application however, it is better to use a diode that can withstand higher voltages like the MBR0540 (0.5 A, 40 V). Schottky diodes, with their low forward voltage drop and fast switching speed, are the best match.
Many different manufacturers make equivalent parts, but make sure that the component is rated to handle at least 0.35 A. Inductor L1, a 4.7-µH choke, is available from Murata, Sumida, Coilcraft, etc. In order to maintain the constant off-time (0.4 ms) control scheme of the LT1615, the on-chip power switch is turned off only after the 350-mA (or 100-mA for the LT1615-1) current limit is reached. There is a 100-ns delay between the time when the current limit is reached and when the switch actually turns off. During this delay, the inductor current exceeds the current limit by a small amount. This current overshoot can be beneficial as it helps increase the amount of available output current for smaller inductor values.
This will be the peak current passed by the inductor (and the diode) during normal operation. Although it is internally current-limited to 350 mA, the power switch of the LT1615 can handle larger currents without problems, but the overall efficiency will suffer. Best results will be o btained when IPEAK is kept well below 700 mA for the LT1615.The LT1615 uses a constant off-time control scheme to provide high efficiencies over a wide range of output current. The LT1615 also contains circuitry to provide protection during start-up and under short-circuit conditions.
When the FB pin voltage is at less than approximately 600 mV, the switch off-time is increased to 1.5 ms and the current limit is reduced to around 250 mA (i.e., 70% of its normal value). This reduces the average inductor current and helps minimize the power dissipation in the LT1615 power switch and in the external inductor L1 and diode D1. The output current is determined by Vref/R1, in this case, 1.23V/68 = 18 mA). Further information on the LT1615 may be found in the device datasheets which may be downloaded from www.linear-tech.com/pdf/16151fa.pdf
The constant-current design of the circuit guarantees a steady current through all LEDs, regardless of the forward voltage differences between them. Although this circuit was designed to operate from a single Li-Ion battery (2.5V to 4.5V), the LT1615 is also capable of operating from inputs as low as 1 V with relevant output power reductions. The Motorola MBR0520 surface mount Schottky diode (0.5 A 20 V) is a good choice for D1 if the output voltage does not exceed 20 V. In this application however, it is better to use a diode that can withstand higher voltages like the MBR0540 (0.5 A, 40 V). Schottky diodes, with their low forward voltage drop and fast switching speed, are the best match.
Many different manufacturers make equivalent parts, but make sure that the component is rated to handle at least 0.35 A. Inductor L1, a 4.7-µH choke, is available from Murata, Sumida, Coilcraft, etc. In order to maintain the constant off-time (0.4 ms) control scheme of the LT1615, the on-chip power switch is turned off only after the 350-mA (or 100-mA for the LT1615-1) current limit is reached. There is a 100-ns delay between the time when the current limit is reached and when the switch actually turns off. During this delay, the inductor current exceeds the current limit by a small amount. This current overshoot can be beneficial as it helps increase the amount of available output current for smaller inductor values.
This will be the peak current passed by the inductor (and the diode) during normal operation. Although it is internally current-limited to 350 mA, the power switch of the LT1615 can handle larger currents without problems, but the overall efficiency will suffer. Best results will be o btained when IPEAK is kept well below 700 mA for the LT1615.The LT1615 uses a constant off-time control scheme to provide high efficiencies over a wide range of output current. The LT1615 also contains circuitry to provide protection during start-up and under short-circuit conditions.
When the FB pin voltage is at less than approximately 600 mV, the switch off-time is increased to 1.5 ms and the current limit is reduced to around 250 mA (i.e., 70% of its normal value). This reduces the average inductor current and helps minimize the power dissipation in the LT1615 power switch and in the external inductor L1 and diode D1. The output current is determined by Vref/R1, in this case, 1.23V/68 = 18 mA). Further information on the LT1615 may be found in the device datasheets which may be downloaded from www.linear-tech.com/pdf/16151fa.pdf
Author: D. Prabakaran
Copyright: Elektor Electronics
Copyright: Elektor Electronics
Wednesday, November 12, 2014
PWM Discrete Generator Circuit and explanation
PWM waveforms are commonly used to control the speed of DC motors. The mark/space ratio of the digital wave-form can be defined either by using an adjustable analogue voltage level (in the case of a NE555 based PWM generator) or digitally using binary values. Digitally derived PWM waveforms are most often produced by the timer/counter modules in microcontrollers but if you do not want to include a microcontroller in your circuit it’s also quite simple to generate the signals using discrete logic components.Circuit diagram:
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Discrete PWM Generator Circuit Diagram
An extension of the circuit shown can produce two PWM wave-forms from an 8-bit digital input word. Each signal has 15 values. The 8-bit word can be produced for example from an expansion board fitted in a PC or from an 8-bit port of a processor which does not have built-in PWM capability or from a laptop’s printer port. The mark/space ratio is only programmable up to 15/16 rather than 16/16; a binary input of 0000 produces a continuous low on both outputs turning both motors off.
Similar circuits often employ a dedicated ‘enable’ input to turn the motors off but it is not necessary in this design. The diagram shows the circuitry required to produce just one waveform. For the full two channel circuit it is necessary to use an additional 74HC193. The clock signal produced by the HCF4060 generator can be used to drive both channels and the free flip flop in the 74HC74 package can be used for the second channel (the corresponding pin numbers are shown in brackets). Altogether the entire two channel circuit can be built using just four ICs.
Discrete PWM Generator Circuit Diagram
An extension of the circuit shown can produce two PWM wave-forms from an 8-bit digital input word. Each signal has 15 values. The 8-bit word can be produced for example from an expansion board fitted in a PC or from an 8-bit port of a processor which does not have built-in PWM capability or from a laptop’s printer port. The mark/space ratio is only programmable up to 15/16 rather than 16/16; a binary input of 0000 produces a continuous low on both outputs turning both motors off.
Similar circuits often employ a dedicated ‘enable’ input to turn the motors off but it is not necessary in this design. The diagram shows the circuitry required to produce just one waveform. For the full two channel circuit it is necessary to use an additional 74HC193. The clock signal produced by the HCF4060 generator can be used to drive both channels and the free flip flop in the 74HC74 package can be used for the second channel (the corresponding pin numbers are shown in brackets). Altogether the entire two channel circuit can be built using just four ICs.
Monday, October 27, 2014
TDA2030 bridge 35 watt power amplifier Diagram Circuit
A very simple 35 watt power amplifier electronic project can be designed using the TDA2030 power audio IC. The TDA2030A is a monolithic IC in Pentawatt package intended for use as low frequency class AB amplifier.
The TDA2030A provides high output current and has very low harmonic and cross-over distortion. TDA2030 ICs connected in bridge mode.
This circuit require few external electronics parts and supports a 8 ohms load . This 35 watt power amplifier require a very good filtered DC power supply , that will provide an output voltage of +/- 16 volts .
Using this circuit you can design a very simple and efficiency subwoofer amplifier with a maximum output power of 35 watt power .
The device incorporates a short circuit protection system comprising an arrangement for automatically limiting the dissipated power so as to keep the working point of the output transistors within their safe operating area. Also a conventional thermal shut-down system is also included .
However a heatsink must be used for the TDA2030 bridge circuit but for any reason, if the junction temperature increases up to 150oC, the thermal shut-down simply reduces the power dissipation and the current consumption.
LM4765 2 x 30 watt amplifier Diagram Circuit
A very simple 2 x 30 watt amplifier electronic circuit project can be designed using the LM4765 stereo audio amplifier IC capable of delivering typically 30W per channel of continuous average output power into an 8Ω load with less than 0.1% THD+N.
This 2 x 30 watt amplifier electronic circuit is very simple and require few external electronic parts and can be used in high end stereo TVs or some other audio applications .
Each amplifier has an independent smooth transition fadein/out mute and a power conserving standby mode which can be controlled by external logic.
Like many other audio amplifier ICs the LM4765 has many features like Temperature protection circuitry, SPiKe protection ( means that these parts are safeguarded at the output against overvoltage, undervoltage, overloads, including thermal runaway and instantaneous temperature peaks).
This audio amplifier electronic circuit project can be powered from a wide input voltage range from 20 volt up to 66 volts , but typically is required a dual 28 volts input ( take care because |Vcc|+|Vee|<60 volts .
The audio IC must be mounted on a heat sink to keep the die temperature at a level such that the thermal protection circuitry does not operate under normal circumstances.
In this circuit diagram is represented just a part of the IC (one channel ) and numbers in parentheses represent pinout for amplifier B
VGA to BNC Adapter Converter Circuit and explanation
There are monitors which only have three BNC inputs and which use composite synchronization (‘sync on green’). This circuit has been designed with these types of monitor in mind. As can be seen, the circuit has been kept very simple, but it still gives a reasonable performance. The principle of operation is very straightforward. The RGB signals from the VGA connector are fed to three BNC connectors via AC-coupling capacitors. These have been added to stop any direct current from entering the VGA card. A pull-up resistor on the green output provides a DC offset, while a transistor (a BS170 MOSFET) can switch this output to ground. It is possible to get synchronisation problems when the display is extremely bright, with a maximum green component.
In this case the value of R2 should be reduced a little, but this has the side effect that the brightness noticeably decreases and the load on the graphics card increases. To keep the colour balance the same, the resistors for the other two colors (R1 en R3) have to be changed to the same value as R2. An EXOR gate from IC1 (74HC86) combines the separate V-sync and H-sync signals into a composite sync signal. Since the sync in DOS-modes is often inverted compared to the modes commonly used by Windows, the output of IC1a is inverted by IC1b. JP1 can then by used to select the correct operating mode. This jumper can be replaced by a small two-way switch, if required.
This switch should be mounted directly onto the PCB, as any connecting wires will cause a lot of interference. The PCB has been kept as compact as possible, so the circuit can be mounted in a small metal (earthed!) enclosure. With a monitor connected the current consumption will be in the region of 30 mA. A 78L05 voltage regulator provides a stable 5 V, making it possible to use any type of mains adapter, as long as it supplies at least 9 V. Diode D2 provides protection against a reverse polarity. LED D1 indicates when the supply is present. The circuit should be powered up before connecting it to an active VGA output, as otherwise the sync signals will feed the circuit via the internal protection diodes of IC1, which can be noticed by a dimly lit LED. This is something best avoided.
Resistors:
R1,R2,R3 = 470Ω
R4 = 100Ω
R5 = 3kΩ3
Capacitors:
C1,C3,C5 = 47µF 25V radial
C2,C4,C6,C7,C10 = 100nF ceramic
C8 = 4µF7 63V radial
C9 = 100µF 25V radial
Semiconductors:
D1 = LED, high-efficiency
D2 = 1N4002
T1 = BS170
IC1 = 74HC86
IC2 = 78L05
Miscellaneous:
JP1 = 3-way pinheader with jumper
K1 = 15-way VGA socket (female), PCB mount (angled pins)
K2,K3,K4 = BNC socket (female), PCB mount, 75Ω
Read More..
In this case the value of R2 should be reduced a little, but this has the side effect that the brightness noticeably decreases and the load on the graphics card increases. To keep the colour balance the same, the resistors for the other two colors (R1 en R3) have to be changed to the same value as R2. An EXOR gate from IC1 (74HC86) combines the separate V-sync and H-sync signals into a composite sync signal. Since the sync in DOS-modes is often inverted compared to the modes commonly used by Windows, the output of IC1a is inverted by IC1b. JP1 can then by used to select the correct operating mode. This jumper can be replaced by a small two-way switch, if required.
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This switch should be mounted directly onto the PCB, as any connecting wires will cause a lot of interference. The PCB has been kept as compact as possible, so the circuit can be mounted in a small metal (earthed!) enclosure. With a monitor connected the current consumption will be in the region of 30 mA. A 78L05 voltage regulator provides a stable 5 V, making it possible to use any type of mains adapter, as long as it supplies at least 9 V. Diode D2 provides protection against a reverse polarity. LED D1 indicates when the supply is present. The circuit should be powered up before connecting it to an active VGA output, as otherwise the sync signals will feed the circuit via the internal protection diodes of IC1, which can be noticed by a dimly lit LED. This is something best avoided.
Resistors:
R1,R2,R3 = 470Ω
R4 = 100Ω
R5 = 3kΩ3
Capacitors:
C1,C3,C5 = 47µF 25V radial
C2,C4,C6,C7,C10 = 100nF ceramic
C8 = 4µF7 63V radial
C9 = 100µF 25V radial
Semiconductors:
D1 = LED, high-efficiency
D2 = 1N4002
T1 = BS170
IC1 = 74HC86
IC2 = 78L05
Miscellaneous:
JP1 = 3-way pinheader with jumper
K1 = 15-way VGA socket (female), PCB mount (angled pins)
K2,K3,K4 = BNC socket (female), PCB mount, 75Ω
Saturday, October 25, 2014
Energy Saver Relay Coil Diagram Circuit
Some relays will become warm if they remain energized for some time. The circuit shown here will actuate the relay as before but then reduce the ‘hold’ current through the relay coil current by about 50%, thus considerably reducing the amount of heat dissipation and wasted power. The circuit is only suitable for relays that remain on for long periods. The following equations will enable the circuit to be dimensioned for the relay on hand: R3 = 0.7 / I Charge time = 0.5 × R2 × C1 Where I is the relay coil current. After the relay has been switched off, a short delay should be allowed for the relay current to return to maximum so the relay can be energized again at full power. To make the delay as short as possible, keep C1 as small as possible. In practice, a minimum delay of about 5 seconds should be allowed but this is open to experimentation.
Circuit diagram:
![]( "Relay")
The action of C2 causes the full supply voltage to appear briefly across the relay coil, which helps to activate the relay as fast as possible. Via T2, a delay network consisting of C1 and R2 controls the relay coil current flowing through T1 and R3, effectively reducing it to half the ‘pull in’ current. Diode D2 discharges C1 when the control voltage is Low. Around one second will be needed to completely discharge C1. T2 shunts the bias current of T1 when the delay has elapsed. Diode D1 helps to discharge C1 as quickly as possible. The relay shown in the circuit was specified at 12 V / 400 ohms. All component values for guidance only.
Circuit diagram:
Relay Coil Energy Saver Circuit Diagram
The action of C2 causes the full supply voltage to appear briefly across the relay coil, which helps to activate the relay as fast as possible. Via T2, a delay network consisting of C1 and R2 controls the relay coil current flowing through T1 and R3, effectively reducing it to half the ‘pull in’ current. Diode D2 discharges C1 when the control voltage is Low. Around one second will be needed to completely discharge C1. T2 shunts the bias current of T1 when the delay has elapsed. Diode D1 helps to discharge C1 as quickly as possible. The relay shown in the circuit was specified at 12 V / 400 ohms. All component values for guidance only.
Author: Myo Min - Copyright: Elektor July-August 2004
Wednesday, October 15, 2014
Build a High And Low Voltage Cut Off With Time Delay Circuit Diagrams
The power line fluctuations and cut-offs cause damages to electrical appliances connected to the line. It is more serious in the case of domestic appliances like fridge and air conditioners. If a fridge is operated on low voltage, excessive current flows through the motor, which heats up, and get damaged.
The under/over voltage protection circuit with time delay presented here is a low cost and reliable circuit for protecting such equipments from damages. Whenever the power line is switched on it gets connected to the appliance only after a delay of a fixed time. If there is hi/low fluctuations beyond sets limits the appliance get disconnected. The system tries to connect the power back after the specific time delay, the delay being counted from the time of disconnection. If the power down time (time for which the voltage is beyond limits) is less than the delay time, the power resumes after the delay: If it is equal or more, then the power resumes directly.
This circuit has been designed, built and evaluated by me to use as a protector for my home refrigerator. This is designed around readily available semi-conductor devices such as standard bipolar medium power NPN transistor (D313/SL100/C1061), an 8-pin type 741 op-amp and NE555 timer IC. Its salient feature is that no relay hunting is employed. This draw back is commonly found in the proctors available in the market.
The complete circuit is consisting of various stages. They are: - Dual rail power supply, Reference voltage source, Voltage comparators for hi/low cut offs, Time delay stage and Relay driver stage. Lets now look at the step-by-step design details.
Dual rail power supply.
This is a conventional type of power supply as shown in Figure 1. The power is applied through the step-down transformer (230/12-0-12V/500mA). The DC proportional to the charging input voltage is obtained from bridge rectifier. Two electrolytics are there to bypass any spikes present. Bridge is capable of handling currents up to 1 Amp.
Output is given by: -
V(out) = 0.71 X V (secondary)
= 0.71 X 24V
= 17.04 V
(This equation is similar for the negative rail as well)
This is a conventional type of power supply as shown in Figure 1. The power is applied through the step-down transformer (230/12-0-12V/500mA). The DC proportional to the charging input voltage is obtained from bridge rectifier. Two electrolytics are there to bypass any spikes present. Bridge is capable of handling currents up to 1 Amp.
Output is given by: -
V(out) = 0.71 X V (secondary)
= 0.71 X 24V
= 17.04 V
(This equation is similar for the negative rail as well)
Circuit diagram
Low voltage cut off op-amp
Figure 2 shows the use of very common and easily available op-amp 741 as a comparator. The op-amp is available in TO-5 and DIP type packing.
Figure 2 shows the use of very common and easily available op-amp 741 as a comparator. The op-amp is available in TO-5 and DIP type packing.
Circuit diagram
In this ckt the zener diode D1 and it’s associated resistor R1 are connected to the non-inverting terminal (+ve) of 741 to give the suitable reference voltage. The DC voltage from the sensor is given to the inverting (-ve) terminal through pre-set R2.This is used to set the input level.
When the sensor input is less than Zener voltage the output from the Op-amp remains high and when it is greater than Zener voltage the output goes low. When the sensing voltage is equal to Zener voltage the output of the op-amp is approximately zero.
This phenomenon is used as a decision for switching the relay and to give cutoff in a low voltage situation.
When the sensor input is less than Zener voltage the output from the Op-amp remains high and when it is greater than Zener voltage the output goes low. When the sensing voltage is equal to Zener voltage the output of the op-amp is approximately zero.
This phenomenon is used as a decision for switching the relay and to give cutoff in a low voltage situation.
High voltage cut off op-amp
Here the op-amp is used as a inverted amplifier. See Figure 3.Zener and resistor network gives reference voltage to the inverting terminal (-ve) of op-amp. Sensing voltage derived through the 10 K pre-set is given to the non- inverting (+ve) terminal and this sets the high level cut.
Here the op-amp is used as a inverted amplifier. See Figure 3.Zener and resistor network gives reference voltage to the inverting terminal (-ve) of op-amp. Sensing voltage derived through the 10 K pre-set is given to the non- inverting (+ve) terminal and this sets the high level cut.
When the input DC from the sensor is less than Zener voltage the output of the op-amp is low and vice-versa. When the input DC voltage is equal to the zener voltage, the op-amps output is approximately zero.
Circuit diagram
Time delay
I’ve selected the 555 timer due to following reasons.
1. Timing from microseconds through hours.
2. Ability to operate from wide range of supply voltages.
3. High temperature stability.
4. Easily Available.
5. Its triggering circuit is quite sensitive.
I’ve selected the 555 timer due to following reasons.
1. Timing from microseconds through hours.
2. Ability to operate from wide range of supply voltages.
3. High temperature stability.
4. Easily Available.
5. Its triggering circuit is quite sensitive.
This is basically a monostable. The external timing capacitor C2 is held initially discharged by the timer. The circuit triggers upon receiving a pulse to its pin 2 when the level reaches 1/3 Vcc. Once triggered., the circuit will remain in that state until the set time is elapsed or power to the circuit cuts off. The delayed period in seconds is 1.1 C2.R1 where R1 is in megohms and C2 is in microfarads. In practice, R1 should not exceed 20 M. If you use an electrolytic capacitor for C2, select a unit for low leakage. The time delay may have to be adjusted by varying R1 to compensate for the wide tolerance of electrolytics.
Circuit diagram
Relay Driver
The output from the voltage level detectors cannot directly drive the relay and hence the relay driver is used.
The output from the voltage level detectors cannot directly drive the relay and hence the relay driver is used.
Circuit diagram
In this a relay (12V <500 ohms) is connected to the collector of npn transistor. the out put voltage from the comparator is applied to the base of npn transistor through a resistance r1. when the output from the comparator is low the transistor is in off state and the relay is in de-energized state. similarly when the output from the comparator goes high the transistor switches on and the flow of current from the collector to emitter of transistor energizes the relay.
Generally in a relay driver circuit, parallel to the relay coil, a diode or a capacitor is used. This is to eliminate the back e.m.f generated by the relay coil when currents are suddenly broken. Capacitor C1 is connected in parallel to the coil, which filters out the back emf but it, slows down the working of relay.
A better method is to connect two diodes (as shown in the figure 5) that stop the relay – transistor junction swinging more than 600mV above the positive rail or below the zero-volt rail. During normal operation the diodes are reverse biased and have no effect on the performance of circuit. But when back emf is induced, the diodes conduct heavily and absorb all transient voltages. However, I have employed the both methods.
The Complete Circuit
Circuit diagram
Under normal operating conditions i.e. when the input voltage is between maximum and minimum limit the output from the both the comparators are low. The transistor Q1 is OFF and the relay is in de-energized (pole connected to N/C pin) state and the output is obtained.
When the input voltage is below or above the limits set by the pre-sets R8 or R9, the output of the Op-Amps goes either low or high and diodes D1 or D2 would be forward biased depending on the situation. Transistor Q1 switches ON and the flow of current from collector to emitter energizes the relay and the output is cutoff.
A small amount of hystersis has been added via feed back resistors R10 & R11 so that the relay turns on when the level falls to a particular value but does not turn again until it raises a substantial amount above this value. Other wise the relay contacts will frequently turn on/off and produce chattering.
Construction Hints
1) I used a piece of varoboard, which has copper strips on one side to mount the components, and housed the entire circuit and the transformer in a discarded ATX PC power supply box.
1) I used a piece of varoboard, which has copper strips on one side to mount the components, and housed the entire circuit and the transformer in a discarded ATX PC power supply box.
2) An autotransformer has been used to set the limits. Set the output of the autotransformer to 250V AC and connect it to the primary of transformer T1 (see Figure 1). Then adjust the pre-set R9 such that relay just energizes. This is the high limit. Next set the output of the autotransformer to 200V AC and adjust the pre-set R8 such that the relay energizes. Please note that these are my preferred limits but you may select any range from say 170 to 270V AC.
3) A neon with a suitable resistor could be connected between the AC supply lines as an ON indicator. Alternatively, LED with a current limiting resistor could be connected between the relay coil so when the relay is energized LED will indicate the situation.
Monday, October 13, 2014
STA575 200 watt stereo power audio amplifier circuit
This power audio amplifier electronic project is based on the STA575 fully integrated power module designed to implement a BASH® amplifier when used in conjunction with STABP01 digital processor. This power audio amplifier electronic project is based on the STA575 is capable to provide a maximum 100 watts output continuous power per channel ( on two channels ) on a 4 or 8 ohms load . The circuit contains all the blocks to build a stereo amplifier. Each single channel is based on the Output Bridge Power Amplifier, and its protection circuit.
STA575 power audio amplifier can be set in three states by the Stby/mute pin: Standby ( Vpin <0.8v), mute (1.6v 4V).
In the Standby mode all the circuits involved in the signal path are in off condition, instead in Mute mode the circuits are biased but the Speakers Outputs are forced to ground potential.
These voltages can be get by the external RC network connected to Stby/Mute pin.
The same block is used to force quickly the I.C. In standby mode or in mute mode when the I.C. dangerous condition has been detected.
The protection of STA575 power audio amplifier are implemented by the Over Temperature, Unbalance .
The Output bridge amplifier makes the single-ended to Differential conversion of the Audio signal using two power amplifiers, one in non-inverting configuration with gain equal to 2 and the other in inverting configuration with unity gain.
![STA575]()
![]( "STA575")
To protect the output transistors of the power bridge a power detector is implemented .
To power this 200 watt stereo power audio amplifier you’ll need a DC power source that will provide the following output voltages : Vs+ = 28V, Vs- = -23V, VCD+ = 20V, VCD- = -20V and you’ll need a 8 ohms load .
In the table bellow you can see values for electronic parts required by this 200 watt stereo power audio amplifier electronic project .
STA575 power audio amplifier can be set in three states by the Stby/mute pin: Standby ( Vpin <0.8v), mute (1.6v
In the Standby mode all the circuits involved in the signal path are in off condition, instead in Mute mode the circuits are biased but the Speakers Outputs are forced to ground potential.
These voltages can be get by the external RC network connected to Stby/Mute pin.
The same block is used to force quickly the I.C. In standby mode or in mute mode when the I.C. dangerous condition has been detected.
The protection of STA575 power audio amplifier are implemented by the Over Temperature, Unbalance .
The Output bridge amplifier makes the single-ended to Differential conversion of the Audio signal using two power amplifiers, one in non-inverting configuration with gain equal to 2 and the other in inverting configuration with unity gain.
To power this 200 watt stereo power audio amplifier you’ll need a DC power source that will provide the following output voltages : Vs+ = 28V, Vs- = -23V, VCD+ = 20V, VCD- = -20V and you’ll need a 8 ohms load .
In the table bellow you can see values for electronic parts required by this 200 watt stereo power audio amplifier electronic project .
Sunday, September 21, 2014
Amplifier simple easy and cheap with IC TA7368P
Indeed , this amplifier is suitable known as the title above. Viewed from the schematic alreaady seen that this amplifier circuit requires little components and parts were cheap. This amplifier requires 1 piece of IC TA7368P is manufactered by TOSHIBA is the price too low, then in addition to IC amplifier requires 3 components elco capacitor whose value is not too big. Maybe if you make this amplifier circuit, the total price of all must not be more than $ 1. This amplifier only has more than 1W output, perhaps because it has little strengthening it so that the output is released is very small. But to make this is quite easy and not too costly.
Capacitor
C1 = 100 uF
C2 = 100uF
C3 = 470uF
IC
IC1 = TA7368P
Good Luck :)
Wednesday, September 17, 2014
BASIC ELECTRIC AND MAGNETIC CIRCUITS
Power and energy are two terms that are often misused. Energy can bethought of as the ability to do work, and it has units such as joules or Btu. Power, on the other hand, is the rate at which energy is generated or used, and therefore it has rate units such as joules/sor Btu/h. There is often confusion about the units for electrical power and energy. Electrical power is measured in watts, which isarate(1J/s=1 watt), so electrical energy is watts multiplied by time—for example, watt-hours.
Be careful not to say”watts per hour,”which is incorrect (eventhoughyou will see this all too often in newspapers or magazines). When a battery delivers current to a load, power is generated by the battery and is dissipated by the load. We can combine (1.1) and (1.2) to find an expression for instantaneous power supplied, or consumed, by a component of a circuit. The key electrical quantities already introduced and the relevant relationships between these quantities are summarized in Table 1.1. Since electrical quantities vary over suchalargerange of magnitudes, you will often find yourself working with very small quantities or very large quantities.
Be careful not to say”watts per hour,”which is incorrect (eventhoughyou will see this all too often in newspapers or magazines). When a battery delivers current to a load, power is generated by the battery and is dissipated by the load. We can combine (1.1) and (1.2) to find an expression for instantaneous power supplied, or consumed, by a component of a circuit. The key electrical quantities already introduced and the relevant relationships between these quantities are summarized in Table 1.1. Since electrical quantities vary over suchalargerange of magnitudes, you will often find yourself working with very small quantities or very large quantities.
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Friday, September 12, 2014
Simple 3 Input and Gate Comparator Wiring diagram Schematic
This is a Simple 3 Input and Gate Comparator Circuit Diagram. This schema has high output only when all three inputs are high. The non inverting-input current, when all three inputs are high, must exceed that of the inverting input, as determined by R4. The schema can be converted to a AND gate by transposing the two inputs of the op amp.
3 Input and Gate Comparator Circuit Diagram
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3 Input and Gate Comparator Circuit Diagram
Saturday, September 6, 2014
Monitor voltage and 5VDC and 12VDC Wiring diagram Schematic
This schema is a voltage monitor which operates on fixed testes ± 5 VDC and ± 12 VDC, and is easily constructed as shown in Fig. It is considerably simpler than the normal display using comparators and AND gates. The schema is not intended to indicate the level of entries. If one of the testes fail, for example, -5 V line fails, the transistor Q3 remains on but the base-emitter junction of T2 is not, so that this transistor is cut off. When this happens, there is no current through D, which then turns off.
Monitor voltage + and - 5VDC + and - 12VDC Circuit Diagram
Wednesday, September 3, 2014
Solar IPod Charger Project and Schematic
Solar iPod Charger Schematic
The Solar Panel
To accomplish our iPod solar charger we acclimated a 250mA 6 Volt Solar Console (available in the REUK Shop). Alike in the brightest sunshine the voltage is not badly aloft that of the iPod battery, and the accepted is affluence abundant to allegation the array in a few hours in ablaze altitude (even in the UK!).
A blocking diode should be acclimated (in the absolute solar console lead) to anticipate the iPod array from boring clarification at night if it is still affiliated to the panel. Unforunately this after-effects in up to 0.7 Volts actuality absent as calefaction in the diode, so it can be larboard out if you adopt to accept a faster charger which will allegation the array in lower ablaze conditions.
Note that abounding solar panels are supplied with a branch adapted blocking diode.
In adjustment to adapt the voltage from our 6 Volt solar console we acclimated an LM317T dent (available from the REUK Shop) in the afterward cool simple schema:A blocking diode should be acclimated (in the absolute solar console lead) to anticipate the iPod array from boring clarification at night if it is still affiliated to the panel. Unforunately this after-effects in up to 0.7 Volts actuality absent as calefaction in the diode, so it can be larboard out if you adopt to accept a faster charger which will allegation the array in lower ablaze conditions.
Note that abounding solar panels are supplied with a branch adapted blocking diode.
Voltage Regulator
...where R1 is a 270 Ohm resistor, and R2 is theresistor used to set the output voltage according to the following equation:
R2 = R1 * ( (VOUT/1.25) -1 )
Since our desired charging voltage is 5 Volts, we see that ideally R2 would be 270 * ((5/1.25) -1) = 810 Ohms. This is not a standard resistor size, however we had an 820 Ohm resistor which should result in an output voltage of 5.05 Volts.
Wiring up the aloft ambit on a prototyping breadboard with a 270 Ohm R1 resistor, and 820 Ohm R2 resistor we can affirm that the achievement voltage is 5.06 Volts - absolute for our iPod charger. It is capital to analysis that the achievement voltage is about 5 Volts application a acceptable multimeter afore attempting to allegation your iPod or the array and/or iPod itself could be damaged.
iPod Solar Charger Prototyping
Connecting the Charger to the iPod
The iPod is supplied with a USB cable. One end is acquainted into the iPod and the added end has a macho USB-A plug.
It can generally be cheaper to buy a cable with a adapted changeable USB-A adapter and cut it off to use in this project. Simply affix the red USB cable wire to the 5V absolute achievement from the LM317T, and the atramentous USB cable wire to the arena (negative).
According the blueprint beneath the 5 Volt achievement from the LM317T should be affiliated to pin 1, and the arena (negative) affiliated to pin 4.
Friday, August 29, 2014
Evolving Technology and Auto Sound Systems
Finding auto sound systems that can keep up with the constantly evolving technology of today is a real challenge for many car and sound enthusiasts not only around the nation but also around the world. There was a time in the not so distant past when car stereos that had CD players or CD disc changers where the cutting edge of technology. New technology however has nearly rendered the CD players in cars as obsolete as long forgotten 8-track players. The sad news is that many carmakers are clinging to the old days and only offer something as modern as cassette players as standard equipment for auto sound systems.
I think those days will soon be forgotten, as cassettes are no longer even in mainstream production. You should also find that as CDs are rapidly becoming replaced by MP3s that take up very little space in our cars and homes, one day very soon we may see that music companies have decided it is no longer cost effective to produce CDs and render all music to digital formats. So, what does this mean for auto sound systems? Its actually good news for savvy manufacturers are well as savvy consumers who have their eyes on the future and the growing role technology is playing in our lives and as well as our commute to work.
Weve seen a recent introduction of satellite radio to our selection of auto sound systems. These stations offer the allure of no commercial interruptions to your music play in exchange for the price of a monthly subscription. At the moment there are two major companies that offer this service to consumers and each have rather proprietary equipment for their use and installation into your car. They are actually offering some rather tempting offers in order to encourage subscribers. Among those wonderful offers are auto sound systems for your vehicle at less than $100 with a prepaid year of subscription services.
For the satellite radio companies this indicates a constantly growing pool of prospective subscribers and the cost of the equipment is a drop in the bucket when compared to customer loyalty and being on the cutting edge of sound technology. The drawback is that you must decide which service you wish to go with before making the purchase. Also while they offer a very nice auto sound system (bare bones kind of kit that only allows for the radio reception in most cases) at a very sweet price, if you want upgrades such as MP3 compatibility, CD players, CD changers, DVD players, GPS, or any number of other new and advanced technology you will still have to purchase those for your sound system at an upgraded price. There are a few packages that come with these things, but the price is a little on the hefty side. Oh the sacrifices we will make for a more enjoyable daily commute.
Know what your expectations are before you decide to purchase the auto sound system of your dream or you could find that it is more the stuff that nightmares are made of than sweet dreams. Do not live in constant fear that if you buy today you will find something you like better 6 months from now, that is a reality. Technology is growing and evolving at a frightening pace. Find the auto sound system that you like best today and make that your purchase. This is a much better option than waiting around indefinitely and purchasing one just as your warranty expires on your car and its time for a trade in and another auto sound system.
Monday, August 25, 2014
OCL 150 Watt with 2N3055 and MJ2955
This is OCL 150 W mono audio amplifier circuit , with impedance 8 Ohms. The supply voltage using 25 volt DC with triple voltage + ,- ,ground. see below this circuit :
Buffer amplifier use PNP transistor is A564 / A733 /A1013 and NPN use D400 / D438. Driver Amplifier use NPN transistor is TIP31 / TIP41 / D401, and PNP transistor use TIP32 / TIP42 / B546. For the transistor booster or end , here I use a 2 x 20355 and MJ2955 . This anplifier is recomended to full range speakers. See pcb line and construction audio amplifier below :
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| Click to view larger |
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| PCB line |
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| Components are already installed |
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| The booster amplifier already installed. |
Thursday, August 21, 2014
Audio amplifier with IC AN7522 AN7523 and TDA2616
The series of amplifiers that are used on the television audio, amplifier used amplifier ICs, including the IC:
• AN7523• AN7522
• TDA2616
Third series of the function with the same system, namely BTL (Bridge Transformer Less). By using such configuration we get several advantages, namely no use coupling capacitors or coupling transformers.
Block diagram of circuit in the IC AN7522, AN7523 and TDA2616 as in the image below :
| Schematic AN7522 |
| AN7523 amplifier schematic |
| Schematic TDA2616 |
Wednesday, August 20, 2014
PWM Controller Circuit using SN75603 and SN75604
Here the schema diagram of PWM Controller which uses complementary half-H peripheral drivers SN75603 and SN75604, with totem-pole outputs rated at 40 V and 2.0 A. These drivers effectively place the motor in a full-bridge configuration, which has the ability to provide bidirectional control.
Timer U1 operates in the astable mode at a frequency of 80 Hz. The 100-Ω discharge resistor results in an 8-μs trigger pulse which is coupled to the trigger input of timer U2. Timer U2 serves as the PWM generator. Capacitor C1 is charged linearly with a constant current of 1 mA from the 1N5297, which is an FET current-regulator diode. Motor speed is controlled by feeding a dc voltage of 0 to 10 V to control input pin 5 of U2. As the control voltage increases, the width of the output pulse pin 3 also increases. These pulses control the on/off time of the two motor drivers. The trigger pulse width of timer U1 limits the minimum possible duty cycle from U2.
Tuesday, August 19, 2014
Adjustable Symmetrical Power Supply Using LM317 and LM337
The schema was designed to provide an adjustment with a power supply that is symmetrically designed while providing a voltage range of 1.25V to 30V at 1A current. LM317 – an adjustable 3-terminal positive voltage regulator capable of supplying in excess of 1.5A over an output voltage range of 1.2V to 37V and requires only two external resistors to set the output voltage due to its internal current limiting, thermal shutdown and safe area compensation, making it essentially blow-out proof LM337 – an adjustable 3-terminal positive voltage regulator capable of supplying in excess of 5A used as battery chargers, constant current regulators, and adjustable power supplies due to its features such as protected output from short schema, product enhancement tested, current limit constant with temperature, guaranteed thermal regulation, adjustable output down to 1.2V, guaranteed 5A, and guaranteed 7A peak output current.
The schema will serve as a voltage converter with an input voltage of 35 V to produce an output voltage of 1.25 V to 30 V. The positive voltage is being handled by LM317 IC while the negative voltage is handled by LM337. The schema can provide an output current of 1 A. During the production of 1 A current, the regulator is dissipating too much heat and without the presence of a heatsink, the regulator may get damaged.
Using these types of regulators provide features such as low noise and low price in the market. It can be made operational even with few components used. The only disadvantage that it will impose is the poor conversion efficiency. With the output of 35 V to 5 V, the efficient ratio of the output power with the input power is less than 42%. This is the reason why the switching regulator became cheap recently although the number of external components to be connected is minimally increased. These regulators will work with better efficiency when used in case where current is more than 1A for more than 15 V and 0.4 A for less than 15 V from the power supply. Each regulator is adjusted for single positive and negative voltage output using the 10K ohms potentiometers RV1 & RV2. For dual outputs, a dual connected potentiometer RV3 is made to operate by switch S1. The visual indication on the voltmeter V1 is shown using the switch S2.
Using these types of regulators provide features such as low noise and low price in the market. It can be made operational even with few components used. The only disadvantage that it will impose is the poor conversion efficiency. With the output of 35 V to 5 V, the efficient ratio of the output power with the input power is less than 42%. This is the reason why the switching regulator became cheap recently although the number of external components to be connected is minimally increased. These regulators will work with better efficiency when used in case where current is more than 1A for more than 15 V and 0.4 A for less than 15 V from the power supply. Each regulator is adjusted for single positive and negative voltage output using the 10K ohms potentiometers RV1 & RV2. For dual outputs, a dual connected potentiometer RV3 is made to operate by switch S1. The visual indication on the voltmeter V1 is shown using the switch S2.
- R1-2=270ohms
- R3-4=2.2Kohms
- R5-6=10Kohms
- C1-5=100uF/63V
- C2-4=100nF/100V
- C3-8=10uF/25V
- C6-10=100uF/63V
- C7-9=100nF/100V
- RV1-2=10Kohms Lin.
- RV3=2X10Kohms Lin.
- IC 1=LM 317T
- IC 2=LM 337T
- D1-2=1N4001
- D3-4=1N4001
- L1-2=LED 3mm
- F1-2=1A slow Blow Fuse
- S1-2=2X ON-ON SW
- V1=0-30V DC Voltmeter
The adjustable symmetrical power supply is suitable to be used in audio amplifiers, microphone amplifiers, op-amp applications, impedance converters and other devices that require regulated positive and negative DC supply, since the output current is 1 A.
Basic Combinations Of Subs And Amps
When we first get a sub for our car a person has multiple choices to choose from. Starting with the basic queries which are how many subs you want and what will be their sizes that go perfectly with your amplifiers. It is necessary to pick subs and amps that are completely compatible with each other otherwise clash between one of them will either decrease the life of them or will not let them work at all. If you already have purchased either one of the subs or amps then Internet is the best way to find its compatible amp or sub respectively. Otherwise, websites like mtx.com have a complete chart that will suggest which amp is compatible and best for a particular sub.
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Now the above mentioned combinations were the basics and common one. You can look for more combinations if you want to experiment and bring the most out of your amps and subs. Only remember a little browsing before buying never goes to waste
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Compatibility of amps and subs are very important otherwise the clash will either take both of the devices down or will unable to play either one of them. The subs and amps can be picked out at the same time to avoid any incompatibility between them but if you already have one of them at home then browse a little on Internet to find out which one of the other best suits it.
In the purchasing of an amplifier the most and the only thing important is to choose how much amount of power you need for your subwoofers. Once you have decided that you can get one that fits the compatibility factor as well as your requirement. A mono amplifier or a two-channel amplifier is the choices in this category though. The four common types of combinations for subwoofers are discussed further.
The bright side of each of these combinations will be kept in mind while choosing the right type of amp for it.
Single 4-ohm Voice coil sub:
As the single voice coil sub has less wiring therefore they are compact, simple and cheaper. They do not take too much room with a great result. This voice coil sub is perfectly compatible with a two-channel amp as they work fine with 4-ohms. Make sure you do not use a mono amp here as they are best well-suited with less than 4-ohms.
One 4-ohm dual voice coil sub:
Dual voice coils as mentioned earlier can be wired in multiple ways making it easier for you which also results in great performance and power handling. Most of the dual voice coil subs are compact too. Mono amps which are built for lower impedance usage and most power production are ideal for this type of voice coil sub.
Two 4-ohm single voice coil subs:
For producing accurate and tight bass you can get two subwoofers to thump harder. This may take up more room but it depends on your priorities – more bass or trunk space? Mono amps are perfect for this category as more power and performance is expected from them.
Two 4-ohm dual voice coil subs:
Again dual voice coil subs provide multiple wiring that brings us to flexibility and convenience. Two-channel amp is again the right choice for here resulting in powerful bass.
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