Showing posts with label circuits. Show all posts
Showing posts with label circuits. Show all posts
Tuesday, November 11, 2014
LED flasher with Transistor circuits Diagram
These circuits only flash one or two LEDs. This is opposed to the light chaser circuits that can flash four or more. Of course, the simplest LED flasher is simply to use a flashing LED. The problem with that approach is you have no control over the flash rate, but it does have its use for eye catching displays for selling stuff. The circuits below give you that control, plus they can flash two LEDs alternately.
There are many possible applications for the circuits below, especially for kids, who love flashing lights. Heres some possible uses.
- Railroad crossing signal for model railroads.
- Safety blinkers for bicycles, etc.
- Fun stuff for Halloween, like making those plastic Jack-O-lanterns blink (try using ultraviolet LEDs here).
- Christmas decorations.
- Blinkers to locate items in the dark.
Transistor LED flasher
This circuit has a lot going for it. For one thing, it only consists of two transistors, two capacitors and four resistors. That also means it consumes very little power. You can control the flash rate by changing the size of the 100k resistors (100k makes for a pretty slow rate). You can also control the duty cycle by using resistors of different values on the two sides. The 470 ohm resistors control the current through the LEDs. Normally you want to limit this to 20mA, but to conserve battery power, you may need to limit it even further. You can also connect several LEDs in series, instead of using only one for each side. With red LEDs (1 per side) and the values shown, the circuit draws about 11mA. Heres what the actual circuit looks like:
On this circuit, the green wires connect to the LEDs, but you can mount them on the actual circuit board for some applications. The picture is about twice actual size.
Sunday, October 26, 2014
LED Lights circuits with LM339 IC555
This circuit reproduces the opening light sequence now used by FISA instead of Formula individual racing. It may possibly befall used with slot car sets (such like HO shin up AFX/Life Like/Tyco sets) or else means of communication controlled cars. IC1, a 555 timer IC, is used as a meter pulse generator. Its output is fed via NAND gates IC2a and IC2c to IC3, a 4024 binary counter. IC2b inverts the O4 output of 4024 binary counter IC3. at first, IC3 is reset and all its outputs are low, together with O4, which causes IC2b to grant a commonsensical climax to the pin 8 input of IC2c which afterward passes pulses from the 555 timepiece circuit to the clock input of the 4024. IC3 then begins including.
Similar to the count has reached binary 1111, the then pulse sends the O4 output of IC3 high, which disables IC2c and IC3 stops together with. The four used outputs of IC3 are connected to a resistor ‘ladder’ which acts because a undemanding digital to analog convert-er (DAC). As the count increases so does the voltage produced by the top of the ladder and this is connected to the inverting inputs of four comparators inside IC4 (an LM339) and to IC5, which is a 741 op amp besides connected for instance a comparator.
The certain inputs of the comparators are connected to the taps of a voltage barrier, with the drumming voltages frozen using VR1, a 100kO trimpot. As IC3 counts, the rising stepped voltage from the DAC ladder switches the comparators on during sequence, preparatory with IC4d and working up to IC5. because each one comparator is bowed on, its put together of LEDs is lit; essential LEDs 1 & 2, so therefore LEDs 3 & 4 and so on. at what time all five pairs of LEDs are lit, the after that pulse from IC1 moves the binary count of IC3 to 10000, so the DAC voltage drops back to zip and all LEDs are extinguished. by the same age, plus additionally stops, as the lofty on O4 causes IC2c to mass expand gate pulses. The circuit it follows that remains stationary until the counter is reset by burning pushbutton switch S1. This allows a new-fangled sequence to kick off.
Similar to the count has reached binary 1111, the then pulse sends the O4 output of IC3 high, which disables IC2c and IC3 stops together with. The four used outputs of IC3 are connected to a resistor ‘ladder’ which acts because a undemanding digital to analog convert-er (DAC). As the count increases so does the voltage produced by the top of the ladder and this is connected to the inverting inputs of four comparators inside IC4 (an LM339) and to IC5, which is a 741 op amp besides connected for instance a comparator.
The certain inputs of the comparators are connected to the taps of a voltage barrier, with the drumming voltages frozen using VR1, a 100kO trimpot. As IC3 counts, the rising stepped voltage from the DAC ladder switches the comparators on during sequence, preparatory with IC4d and working up to IC5. because each one comparator is bowed on, its put together of LEDs is lit; essential LEDs 1 & 2, so therefore LEDs 3 & 4 and so on. at what time all five pairs of LEDs are lit, the after that pulse from IC1 moves the binary count of IC3 to 10000, so the DAC voltage drops back to zip and all LEDs are extinguished. by the same age, plus additionally stops, as the lofty on O4 causes IC2c to mass expand gate pulses. The circuit it follows that remains stationary until the counter is reset by burning pushbutton switch S1. This allows a new-fangled sequence to kick off.
Friday, October 17, 2014
25W Audio Power Amplifier Circuits Diagram
This audio power amplifier project is based on LM1875 amplifier module from National Semiconductor. It can deliver up to 30W of power using an 8 ohm load & dual 30V DC power supplies. It is designed to operate with maximum outside parts with current limit & thermal shutdown protection features . Other features include high gain, quick slew rate, wide power supply range, giant output voltage swing & high current capability.
Summary of the audio amply-fire features:
Summary of the audio amply-fire features:
- Low distortion: 0.015%, 1 kHz, 20 W
- Wide power bandwidth: 70 kHz
- Wide supply range 16V-60V
- Up to 30 watts output power
- Internal output protection diodes
- Protection for AC & DC short circuits to ground
- 94 dB ripple rejection
- Plastic power package TO-220
25V Power Supply
The schematic below shows how the +25V DC & -25V DC are obtained. In order to provide power supply for two stereo amplifiers, a power transformer rating of 80VA with 240V/36V middle tapped secondary winding is used. The secondary output of the transformer is rectified by using 1N5401 diodes together with four electrolytic capacitors to smoother the ripple voltage. A fuse & a varistor are connected at the primary input to protect the circuit against power surge.
The schematic below shows how the +25V DC & -25V DC are obtained. In order to provide power supply for two stereo amplifiers, a power transformer rating of 80VA with 240V/36V middle tapped secondary winding is used. The secondary output of the transformer is rectified by using 1N5401 diodes together with four electrolytic capacitors to smoother the ripple voltage. A fuse & a varistor are connected at the primary input to protect the circuit against power surge.
Audio Amplifier Module
The +25V & -25V DC power supply are connected to the audio amplifier module through a 2A fuse with the peripheral devices shown in the schematic below. The audio input signal to be amplified is coupled to pin one of LM1875 through the resistor R1 and electrolytic capacitor E5.
The +25V & -25V DC power supply are connected to the audio amplifier module through a 2A fuse with the peripheral devices shown in the schematic below. The audio input signal to be amplified is coupled to pin one of LM1875 through the resistor R1 and electrolytic capacitor E5.
The output signal at pin four of LM1875 can be used to directly drive a 8 ohm loudspeaker. Resistor R6 and capacitor C5 prevent-the capacitance developed at the long speaker leads from driving the amplifier in to High Frequency Oscillation.
A heat-sink with a thermal resistance rating of one.4 Cecilius/Watt or better must be used or else the amplifier module will-be cut-off from operation due to the heat that will build up in the coursework of the operation of the amplifier. Take note that the heat sink tab on the IC module is internally connected to the -25V power supply hence it must be isolated from the heat sink by the use of an insulating washer. If this is not done, the negative rail will be shorted to ground.
A heat-sink with a thermal resistance rating of one.4 Cecilius/Watt or better must be used or else the amplifier module will-be cut-off from operation due to the heat that will build up in the coursework of the operation of the amplifier. Take note that the heat sink tab on the IC module is internally connected to the -25V power supply hence it must be isolated from the heat sink by the use of an insulating washer. If this is not done, the negative rail will be shorted to ground.
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.
Click here to Download BASIC ELECTRIC AND MAGNETIC CIRCUITS
Tuesday, August 12, 2014
Mobile phon Circuits to Get Even smaller
Transceivers, appliances such as mobile phones that can send and receive messages, have become smaller and smaller over the last few years, but users are about to experience a new meaning in miniaturisation.
Research at The Hong Kong University of Science & Technology (HKUST) has successfully combined a unique system architecture and new schema design techniques to reduce them in size like never before.
Research at The Hong Kong University of Science & Technology (HKUST) has successfully combined a unique system architecture and new schema design techniques to reduce them in size like never before.
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| Transceiver schemary (left) and Dr Leung’s equivalent combining off-chip components |
His research group proposed and demonstrated schema techniques that make it possible to combine many of these components to a single chip and therefore to significantly reduce the size of schemary (see example in graphic). A US patent has been granted for one of the schema techniques.
The transformation applies to the CMOS (Complimentary Metal-Oxide Semiconductor) manufacturing process, which can produce integrated diagram and systems with the highest integration level at the lowest cost. Applying new techniques to the CMOS process, Dr Luong’s research enables many “off-chip” components to be combined to realize a system-on-chip. “But,” he said, “this integration created great challenges in schema implementation.” Part of the research was to solve the problems by new schema design techniques.
“The system architecture and schemary go hand in hand, he added. “They must both work, or neither will be useful.”
The resulting design gives the highest component integration in the smallest chip area ever reported, said Dr Luong.
In his design, all off-chip components are fitted into a central chip measuring 36 mm
with packaging, and 8mm without being packaged.
Dr Luong’s miniaturisation method means appliances will soon be made for even lower cost and lower power consumption in addition to being much smaller in size and lighter in weight.
“With the lowering of cost, size and power, many new and interesting applications will become possible and practical,” he said.
Low-power wireless transceivers, for example, could be integrated into implanted devices such as heart pacemakers to wirelessly transmit and receive information between patients and doctors or monitoring systems.
Wearable mobile phones as small as wrist watches at an affordable price could also become a reality.
The transformation applies to the CMOS (Complimentary Metal-Oxide Semiconductor) manufacturing process, which can produce integrated diagram and systems with the highest integration level at the lowest cost. Applying new techniques to the CMOS process, Dr Luong’s research enables many “off-chip” components to be combined to realize a system-on-chip. “But,” he said, “this integration created great challenges in schema implementation.” Part of the research was to solve the problems by new schema design techniques.
“The system architecture and schemary go hand in hand, he added. “They must both work, or neither will be useful.”
The resulting design gives the highest component integration in the smallest chip area ever reported, said Dr Luong.
In his design, all off-chip components are fitted into a central chip measuring 36 mm
with packaging, and 8mm without being packaged. Dr Luong’s miniaturisation method means appliances will soon be made for even lower cost and lower power consumption in addition to being much smaller in size and lighter in weight.
“With the lowering of cost, size and power, many new and interesting applications will become possible and practical,” he said.
Low-power wireless transceivers, for example, could be integrated into implanted devices such as heart pacemakers to wirelessly transmit and receive information between patients and doctors or monitoring systems.
Wearable mobile phones as small as wrist watches at an affordable price could also become a reality.
Auther
Principal Investigator
Dr Howard Luong
Sunday, August 10, 2014
Build a Simple 90Vrms Voltage Regulator Circuits Wiring diagram
This is a Simple 90Vrms Voltage Regulator Circuits Diagram. The 90Vrms Voltage Regulator Circuits Diagram is an open loop rms voltage regulator that will provide 500 watts of power at 90 V rms with good regulation for an input voltage range of 110-130 V rms. With the input voltage applied, capacitor Cl charges until the firing point of Q3 is reached causing it to fire.
This turns Q5 on which allows current to flow through the load. As the input voltage increases, the voltage across R10 increases which increases the firing point of Q3. This delays the firing of Q3 because Cl now has to charge to a higher voltage before the peak-point voltage is reached.Thus the output voltage is held fairly constant by delaying the firing of Q5 as the input voltage increases. For a decrease in the input voltage, the reverse occurs.
90Vrms Voltage Regulator Circuits Diagram
Saturday, August 9, 2014
Wire Break Alarm With Delay Circuits Wiring diagram
Simple Wire-Break Alarm With Delay Alarm and Security Here is a simple schema of wire-break alarm that activates after a delay of 15 to 30 seconds. When the thin-wire loop running across the entrance door is broken, the alarm sounds after a delay of 15 to 30 seconds, the time period set through VR1. Thus the occupants get sufficient time to lock the room from the outside and catch the thief.
The schema uses CD4060, which is a 14-stage ripple-carry binary counter/divider and oscillator. It is wired as a timer here and does not need input pulse for trigger. CD4060 gets activated as soon as the power supply is switched on. Output O13 of CD4060 goes high after the lapse of preset delay set through VR1. Transistor SL100 (T2) is wired as a switch to power the timer section built around CD4060. When the wire loop is closed, transistor T2 does not conduct. So power to the timer schema is not available and the piezo buzzer does not sound.
Wire-Break Alarm With Delay Circuit Schematic
On the other hand, when the wire loop is broken by some intruder, transistor T2 conducts to power the schema and the piezobuzzer sounds after 15 to 30 seconds. IC1 can be reset by connecting the wire loop or interrupting the supply. The schema works off regulated 9V-12V. Assemble it on a general-purpose PCB and enclose in a metallic or plastic box of appropriate size. Connect piezobuzzer PZ1 through external wires and complete the installation.
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