October 2014 | Schematic Rise

Friday, October 31, 2014

IR Remote Transmitter Receiver

I use my computer every single minute, I do my work at home and I need to finish lots of paperwork. My computer helps me in almost everything I do. I make sure that my pc is able to do multitasking and functioning well. Just like our body, it should be fit to do all the workload that must be finished within the day.

IR Remote - Transmitter

To come up with another task that a pc can add to its functions, an IR remote was created through an FTDI that receives and transmits data other than the Universal Serial Bus. This is definitely a big help that my pc can easily cope up with simultaneously.

IR Remote Receiver

source: extremecircuit.net

300 Watt MOSFET Broadband Amplifier Using MRF141G

The following segment will provide the enhanced Motorola schematic for any typical application for the MRF141G (which includes parasitic stabilization features), a broadband power RF MOSFET which will place out a conservatively-rated 300 watts across the FM broadcast band. The flange about the MRF141G ought to be mounted to a heat spreader, a copper plate 5/16" thick and 6" x 8", which is then mounted to the heatsink with 6-32 machine screws, if your heatsink is drilled and tapped.

I recommend getting the two transformer assemblies, instead of trying to create them, due to the fact 15-ohm hardline is not straightforward to come across.

Outdoor Lighting Controller Circuit Diagram

When you step out of your brightly-lit house into the darkness, it takes a while for your vision to adjust. A solution to this problem is this outdoor light with automatic switch-off. As a bonus, it will also make it a little bit easier to find the keyhole when returning late at night. Often no mains neutral connection is avail-able at the point where the switch-off timer is to be installed, which makes many circuit arrangements impractical. However, the circuit here is designed to work in this situation. The design eschews bulky components such as transformers and the whole unit can be built into a flush-mounted fitting. The circuit also features low quiescent current consumption.

Outdoor Lighting Controller Circuit Diagram :

Outdoor

Outdoor

The circuit is star ted by closing switch (or pushbutton) S1. The lamp then immediately receives power via the bridge rectifier. The drop across diodes D5 to D10 is 4.2 V, which provides the power supply for the delay circuit itself, built around the CD4060 binary counter.

When the switch is opened the lighting sup-ply current continues to flow through Tri1. The NPN optocoupler in the triac drive circuit detects when the triac is active, with antiparallel LED D1 keeping the drive sym-metrical. The NPN phototransistor inside the coupler creates a reset pulse via T1, driving pin 12 of the counter. This means that the full time period will run even if the circuit is retriggered. The CD4060 counts at the AC grid frequency. Pin 3 goes high after 213clocks, which corresponds to about 2.5 minutes. If this is not long enough, a further CD4060 counter can be cascaded. T2 then turns on and shorts the internal LED of opto-triac IC2; this causes Tri1 to be deprived of its trigger current and the light goes out. The circuit remains without power until next triggered.

The circuit is only suitable for use with resistive loads. With the components shown (in particular in the bridge rectifier and D5 to D10) the maximum total power of the connected bulb(s) is 200 watts. As is well known, the filament of the bulb is most likely to fail at the moment power is applied. There is little risk to Tri1 at this point as it is bridged by the switch. The most likely consequence of overload is that one of diodes D1 to D6 will fail. In the prototype no fuse was used, as it would not in any case have been easy to change. However, that is not necessarily recommended practice!

Circuits at AC line potential should only be constructed by suitably experienced persons and all relevant safety precautions and applicable regulations must be observed during construction and installation.

Author : Harald Schad - Copyright : Elektor

Thursday, October 30, 2014

What is The Parallel Resonance Circuit

The Parallel Resonance Circuit, In numerous ways a parallel resonance circuit is precisely the identical as the series resonance circuit we looked at in the preceding tutorial. Both are 3-element systems that comprise two reactive constituents making them a second-order circuit, both are influenced by variations in the supply frequency and both have a frequency point where their two reactive constituents cancel each other out influencing the characteristics of the circuit. Both circuits have a resonant frequency issue.

The difference this time however, is that a parallel resonance circuit is influenced by the currents flowing through each parallel branch within the parallel LC tank circuit. A tank circuitis a parallel combination of L and C that is used in filter networks to either select or reject AC frequencies. Consider the parallel RLC circuit below.

Parallel RLC Circuit

parallel rlc circuit

Let us define what we already know about parallel RLC circuits.

A parallel circuit containing a resistance, R, an inductance, L and a capacitance, C will produce a parallel resonance(also called anti-resonance) circuit when the resultant current through the parallel combination is in phase with the supply voltage. At resonance there will be a large circulating current between the inductor and the capacitor due to the energy of the oscillations.

A parallel resonant circuit stores the circuit energy in the magnetic field of the inductor and the electric field of the capacitor. This energy is constantly being transferred back and forth between the inductor and the capacitor which results in zero current and energy being drawn from the supply. This is because the corresponding instantaneous values of I_L and I_C will always be equal and opposite and therefore the current drawn from the supply is the vector addition of these two currents and the current flowing in I_R.

In the solution of AC parallel resonance circuits we know that the supply voltage is common for all branches, so this can be taken as our reference vector. Each parallel branch must be treated separately as with series circuits so that the total supply current taken by the parallel circuit is the vector addition of the individual branch currents. Then there are two methods available to us in the analysis of parallel resonance circuits. We can calculate the current in each branch and then add together or calculate the admittance of each branch to find the total current.

We know from the previous series resonance tutorial that resonance takes place when V_L = -V_C and this situation occurs when the two reactances are equal, X_L = X_C. The admittance of a parallel circuit is given as:

Resonance occurs when X_L = X_C and the imaginary parts of Y become zero. Then:

Notice that at resonance the parallel circuit produces the same equation as for the series resonance circuit. Therefore, it makes no difference if the inductor or capacitor are connected in parallel or series. Also at resonance the parallel LC tank circuit acts like an open circuit with the circuit current being determined by the resistor, R only. So the total impedance of a parallel resonance circuit at resonance becomes just the value of the resistance in the circuit and Z = R as shown.

At resonance, the impedance of the parallel circuit is at its maximum value and equal to the resistance of the circuit and we can change the circuits frequency response by changing the value of this resistance. Changing the value of R affects the amount of current that flows through the circuit at resonance, if both L and C remain constant. Then the impedance of the circuit at resonance Z = R_MAX is called the "dynamic impedance" of the circuit.

Impedance in a Parallel Resonance Circuit

impedance in a parallel resonance circuit

Note that if the parallel circuits impedance is at its maximum at resonance then consequently, the circuits admittance must be at its minimum and one of the characteristics of a parallel resonance circuit is that admittance is very low limiting the circuits current. Unlike the series resonance circuit, the resistor in a parallel resonance circuit has a damping effect on the circuits bandwidth making the circuit less selective.

Also, since the circuit current is constant for any value of impedance, Z, the voltage across a parallel resonance circuit will have the same shape as the total impedance and for a parallel circuit the voltage waveform is generally taken from across the capacitor.

We now know that at the resonant frequency, ƒ_r the admittance of the circuit is at its minimum and is equal to the conductance, G given by 1/R because in a parallel resonance circuit the imaginary part of admittance, i.e. the susceptance, B is zero because B_L = B_Cas shown.

Susceptance at Resonance

susceptance at resonance

From above, the inductive susceptance, B_L is inversely proportional to the frequency as represented by the hyperbolic curve. The capacitive susceptance, B_C is directly proportional to the frequency and is therefore represented by a straight line. The final curve shows the plot of total susceptance of the parallel resonance circuit versus the frequency and is the difference between the two susceptances.

Then we can see that at the resonant frequency point were it crosses the horizontal axis the total circuit susceptance is zero. Below the resonant frequency point, the inductive susceptance dominates the circuit producing a "lagging" power factor, whereas above the resonant frequency point the capacitive susceptance dominates producing a "leading" power factor. So at resonant frequency, the circuits current must be "in-phase" with the applied voltage as there effectively there is only the resistance in the circuit so the power factor becomes one or unity, ( θ = 0^o ).

Current in a Parallel Resonance Circuit

As the total susceptance is zero at the resonant frequency, the admittance is at its minimum and is equal to the conductance, G. Therefore at resonance the current flowing through the circuit must also be at its minimum as the inductive and capacitive branch currents are equal ( I_L = I_C ) and are 180^o out of phase.

We remember that the total current flowing in a parallel RLC circuit is equal to the vector sum of the individual branch currents and for a given frequency is calculated as:

At resonance, currents I_L and I_L are equal and cancelling giving a net reactive current equal to zero. Then at resonance the above equation becomes.

Since the current flowing through a parallel resonance circuit is the product of voltage divided by impedance, at resonance the impedance, Z is at its maximum value, ( =R ). Therefore, the circuit current at this frequency will be at its minimum value of V/R and the graph of current against frequency for a parallel resonance circuit is given as.

Parallel Circuit Current at Resonance

The frequency response curve of a parallel resonance circuit shows that the magnitude of the current is a function of frequency and plotting this onto a graph shows us that the response starts at its maximum value, reaches its minimum value at the resonance frequency when I_MIN = I_Rand then increases again to maximum as ƒ becomes infinite. The result of this is that the magnitude of the current flowing through the inductor, L and the capacitor, C tank circuit can become many times larger than the supply current, even at resonance but as they are equal and at opposition ( 180^o out-of-phase ) they effectively cancel each other out.

As a parallel resonance circuit only functions on resonant frequency, this type of circuit is also known as an Rejector Circuit because at resonance, the impedance of the circuit is at its maximum thereby suppressing or rejecting the current whose frequency is equal to its resonant frequency. The effect of resonance in a parallel circuit is also called "current resonance".

The calculations and graphs used above for defining a parallel resonance circuit are similar to those we used for a series circuit. However, the characteristics and graphs drawn for a parallel circuit are exactly opposite to that of series circuits with the parallel circuits maximum and minimum impedance, current and magnification being reversed. Which is why a parallel resonance circuit is also called an Anti-resonance circuit.

Bandwidth & Selectivity of a Parallel Resonance Circuit

The bandwidth of a parallel resonance circuit is defined in exactly the same way as for the series resonance circuit. The upper and lower cut-off frequencies given as: ƒ_upper and ƒ_lower respectively denote the half-power frequencies where the power dissipated in the circuit is half of the full power dissipated at the resonant frequency 0.5( I² R ) which gives us the same -3dB points at a current value that is equal to 70.7% of its maximum resonant value, ( 0.707 x I )² R.

As with the series circuit, if the resonant frequency remains constant, an increase in the quality factor, Q will cause a decrease in the bandwidth and likewise, a decrease in the quality factor will cause an increase in the bandwidth as defined by: BW = ƒ_r /Q or BW = ƒ₂ - ƒ₂. Also changing the ratio between the inductor, L and the capacitor, C, or the value of the resistance, R the bandwidth and therefore the frequency response of the circuit will be changed for a fixed resonant frequency. This technique is used extensively in tuning circuits for radio and television transmitters and receivers.

The selectivity or Q-factor for a parallel resonance circuit is generally defined as the ratio of the circulating branch currents to the supply current and is given as:

Note that the Q-factor of a parallel resonance circuit is the inverse of the expression for the Q-factor of the series circuit. Also in series resonance circuits the Q-factor gives the voltage magnification of the circuit, whereas in a parallel circuit it gives the current magnification.

Bandwidth of a Parallel Resonance Circuit

Example No1

A parallel resonance network consisting of a resistor of 60Ω, a capacitor of 120uF and an inductor of 200mH is connected across a sinusoidal supply voltage which has a constant output of 100 volts at all frequencies. Calculate, the resonant frequency, the quality factor and the bandwidth of the circuit, the circuit current at resonance and current magnification.

Example

Resonant Frequency, ƒ_r

Resonant

Inductive Reactance at Resonance, X_L

Quality factor, Q

Bandwidth, BW

The upper and lower -3dB frequency points, ƒ_H and ƒ_L

Cut-off

Circuit Current at Resonance, I_T

At resonance the dynamic impedance of the circuit is equal to R

Current Magnification, I_mag

Note that the current at resonance (the resistive current) is only 1.67 amps, while the current flowing around the LC tank circuit is larger at 2.45 amps. We can check this value by calculating the current flowing through the inductor (or capacitor) at resonance.

Parallel Resonance Tutorial Summary

We have seen that Parallel Resonance circuits are similar to series resonance circuits. Resonance occurs in a parallel RLC circuit when the total circuit current is "in-phase" with the supply voltage as the two reactive components cancel each other out. At resonance the admittance of the circuit is at its minimum and is equal to the conductance of the circuit. Also at resonance the current drawn from the supply is also at its minimum and is determined by the value of the parallel resistance.

The equation used to calculate the resonant frequency point is the same for the previous series circuit. However, while the use of either pure or impure components in the series RLC circuit does not affect the calculation of the resonance frequency, but in a parallel RLC circuit it does.

In this tutorial about parallel resonance, we have assumed that the components are purely inductive and purely capacitive with negligible resistance. However in reality the coil will contain some resistance. Then the equation for calculating the parallel resonant frequency of a circuit is therefore modified to account for the additional resistance.

Resonant Frequency using Impure Components

Parallel

Project Mini RS232 Data Switch Circuit Diagram

This is the Project of Mini RS232 Data Switch Circuit Diagram. Only simple materials and a little bit of skill are needed to build an RS232 switch. All that you need are two 9-way sub-D plugs with solder pins, a small piece of sheet aluminium, two sets of screw retainer posts, a 4-pole double-throw switch, a strain relief sleeve and a suitable plastic connector shell for a 25-way sub-D connector, with both in-line and right-angle cable entries (such as Conrad Electronics #711322). What is important is that the side cable entry together with its associated strain relief leaves enough room for the switch. If necessary, you may have to cut away a few square millimetres of the sidewall or a few ribs of the plastic shell.

Project image :

Mini

Mini RS232 Data Switch Image

The switch is operated via the in-line cable opening, as can be seen from the photo. A suitable switch with an overall length of 29 mm can be found in the Conrad catalogue under order number 708232. The only modification that must be made to the connector shell is to drill two holes for the retaining screws for the switch (M2.6 screws) at a spacing of 24 mm.

Mini RS232 Data Switch Circuit diagram :

Mini

Mini RS232 Data Switch Circuit Diagram

Connect the two sub-D connectors together using the piece of aluminium and the screw retainer posts. Then solder the cable to the connectors and the switch as indicated. The two connectors are wired somewhat differently. While the upper sub-D plug is connected 1:1 with the input cable (with the switch in the appropriate position), the DCD, DTR, DSR and RI pins of the lower connector are left open. This is because RTS and CTS are fully sufficient for handshaking, as long as DTR and DSR are connected to each other. The only leads that are switched are RXD, RTS, TSD and CTS. The ground potential is fed from the cable to both connectors. After everything has been properly soldered together, you can fit everything into the cable shell as shown.

Mini Stereo Power Amplifier using TDA2822

This circuit TDA2822 total to the same extent your primary device. The Dual Amplifier IC before IC stereo increase by 40 dB. Bandwidth 120 kHZ. with the purpose of is regarding 2 watts and watt power supply of 1.8 to 15 volts and a current 6 mA no more than after using the power supply 9 volt into this circuit.VR1 and VR2 to adjust the suggest level of the best and not here, the pin 7 and pin 6 of IC1.The amplifier IC1 is outmoded of the output pin 1 and pin 3, through the C4 and C5 coupling signals to the absent and right speakers.The C6, R1 and C7, R2 is to reduce blast.

Mini

Mini Stereo Power Amplifier using TDA2822 Circuit Diagram

On Demand WC Fan Using 555 Circuit Diagram

In most WCs with an extractor the fan is connected to the lighting circuit and is switched on and off either in sympathy with the light or with a short delay. Since toilets are sometimes used for washing the hands or just for a quick look in the mirror, it is not always necessary to change the air in the smallest room in the house. The following circuit automatically determines whether there really is any need to run the fan and reacts appropriately. No odour sensor is needed: we just employ a small contact that detects when and for how long the toilet seat lid is lifted.

On-Demand WC Fan circuit Using 555

On-Demand

If the seat lid is left up for at least some presettable minimum time t1, the fan is set running for another presettable time t2. In the example shown the contact is made using a small magnet on the lid and a reed switch mounted on the cistern. The rest is straightforward: IC2, the familiar 555, forms a timer whose period can be adjusted up to approximately 10 to 12 minutes using P2. This determines the fan running time. There are three CMOS NAND gates (type 4093) between the reed switch and the timer input which generate the required trigger signal. When the lid is in the ‘up’ position the reed switch is closed.

Capacitor C1 charges through P1 until it reaches the point where the output of IC1a switches from logic 1 to logic 0. The output of IC1b then goes to logic 1. The edge of the 0-1 transition, passed through the RC network formed by C2 and R2, results in the output of IC1c going to logic 0 for a second. This is taken to the trigger input on pin 2 of timer IC2, which in turn switches on the relay which causes the fan to run for the period of time determined by P2. The circuit is powered from a small transformer with a secondary winding delivering between approximately 8 V and 10 V. Do not forget to include a suitable fuse on the primary side.

The circuit around IC1b and IC1c ensures that the fan does not run continuously if the toilet seat lid is left up for an extended period. The time constant of P1 and C1 is set so that the fan does not run as a result of lavatorial transactions of a more minor nature, where the lid is opened and then closed shortly afterwards, before C1 has a chance to charge sufficiently to trigger the circuit.

Wednesday, October 29, 2014

Fog Lamp Sensor Circuit Diagram

Here are simple Fog Lamp Sensor Circuit Diagram. For several years now, a rear fog lamp has been mandatory for trailers and caravans in order to improve visibility under foggy conditions.

Circuit diagram :

Fog Lamp Sensor Circuit Diagram

When this fog lamp is switched on, the fog lamp of the pulling vehicle must be switched off to avoid irritating reflections. For this purpose, a mechanical switch is now built into the 13-way female connector in order to switch off the fog lamp of the pulling vehicle and switch on the fog lamp of the trailer or caravan. For anyone who uses a 7-way connector, this switching can also be implemented electronically with the aid of the circuit illustrated here.

Here a type P521 optocoupler detects whether the fog lamp of the caravan or trailer is connected. If the fog lamp is switched on in the car, a current flows through the caravan fog lamp via diodes D1 and D2. This causes the LED in the optocoupler to light up, with the result that the phototransistor conducts and energises the relay via transistor T1. The relay switches off the fog lamp of the car.

For anyone who’s not all thumbs, this small circuit can easily be built on a small piece of perforated circuit board and then fitted somewhere close to the rear lamp fitting of the pulling vehicle.

Author :Harrie Dogge - Copyright : Elektor

Variable DC Power Supply with 2N3055 This is variable power supply for multi purpose usage and very useful to supply your electronic tools or your pro

Variable DC Power Supply with 2N3055

This is variable power supply for multi purpose usage and very useful to supply your electronic tools or your projects. Voltage range will be 0.7 - 24V and the urrent limiting range is 50mA - 2A.

Variable

Components:

P1____________500R Linear Potentiometer
P2_____________10K Log. Potentiometer

R1,R2__________2K2 1/2W Resistors
R3____________330R 1/4W Resistor
R4____________150R 1/4W Resistor
R5______________1R 5W Resistor

C1__________3300µF 35V Electrolytic Capacitor (see Notes)
C2_____________1µF 63V Polyester Capacitor

D1,D2_______1N5402 200V 3A Diodes
D3____________5mm. Red LED

Q1___________BC182 50V 100mA NPN Transistor
Q2___________BD139 80V 1.5A NPN Transistor
Q3___________BC212 50V 100mA PNP Transistor
Q4 _________2N3055 60V 15A NPN Transistor

T1____________220V Primary, 36V Center-tapped Secondary
 50VA Mains transformer (see Notes)
PL1___________Male Mains plug
SW1___________SPST Mains switch

Notes:

P1 sets the maximum output current you want to be delivered by the power supply at a given output voltage.
P2 sets the output voltage and must be a logarithmic taper type, in order to obtain a more linear scale voltage indication.
You can choose the Transformer on the grounds of maximum voltage and current output needed. Best choices are: 36, 40 or 48V center-tapped and 50, 75, 80 or 100VA.
Capacitor C1 can be 2200 to 6800µF, 35 to 50V.
Q4 must be mounted on a good heatsink in order to withstand sustained output short-circuit. In some cases the rear panel of the metal box in which you will enclose the circuit can do the job.
The 2N3055 transistor (Q4) can be replaced with the slightly less powerful TIP3055 type.

Triangle Square Wave Oscillator Circuit Diagram

By making Rt variable it is possible to alter the operating frequency over a 100 to 1 range. Versatile triangle/squarenvave oscillator has a possible frequency range of 0 Hz to 100 kHz.

Simple Triangle Square Wave Oscillator Circuit Diagram

Simple

Equalising HEXFETs

When experimenting with audio output stages featuring multiple HEXFETs it quickly becomes apparent that the total power is not divided equally among the individual transistors. The reason for this lies in the wide part-to-part variations in gate-source voltage, which in the case of the IRFP240 (or IRFP9240) can be from 2 V to 4 V. Source resistors in the region of 0.22 Ω as commonly seen in amplifier circuits (see example circuit extract) help to counteract this, but usually not to a sufficient extent. One possible solution to this problem is to ‘select’ the transistors used so that their gate-source voltages match as closely as possible.

Equalising HEXFETs Circuit Diagram

Equalising

For building prototypes or very short production runs this is feasible, but requires additional manual effort in testing the components, and, of course, more transistors must be ordered than will ﬁnally be used. The circuit idea shown here allows differences in gate-source voltage between pairs of transistors to be compensated for by the addition of trimmer potentiometers: the idea has been tested in simulation using Simetrix. The second circuit extract shows the required changes.

Tuesday, October 28, 2014

Mini 2x75W Stereo Power Amplifier

Your search for audio power amplifier with 75W stereo power with a slim body, you can use this Pyle - Mini 2x75W Stereo Power Amplifier - PCA3 . Power amp is designed simply and easily be placed anywhere, not just a good amplifier design is also very good in terms of sound quality in its gain. You can use this amplifier with a media player with a voice like VCD, DVD, Tape, etc.. What are you waiting you can buy the amplifier via the link below :

Pyle - Mini 2x75W Stereo Power Amplifier - PCA3

Standard Microcontroller

Embedded systems are not scarcely set of buildings projects in vogue electronic laboratories--they are contemporary in everyday strategy. each portable device, emotional toy or else kitchen appliance has a little electronic board which mostly includes a programmable device--microcontroller. This is a special microprocessor with peripheral strategy and I/O ports. Depending on the volume of the device the manufacturer can decide whether to develop an ASIC--a keen integrated circuit which performs all functions on behalf of this device before to progress to a standard board with discrete components. within both hand baggage a quantity of microcontroller is used, either for example a soft basis in ASIC otherwise a standard integrated circuit.

Standard

present is a glut of choices from release-source projects to various IP cores with hefty royalties designed for every device. Despite this alternative at hand are the minority microcontroller families to are fashionable as of their flexibility, powerful development tools or else since of historical reasons.

ARM

This is at present the most up-to-date RISC underlying used fashionable almost all cellular phone phones, portable campaign and many other applications. It has powerful direction arrangement, low consumption, offers calm integration and nearby are many superior development tools meant for easy development and debugging. The ARM middle is furthermore used in many general microcontroller families from Atmel, Luminary Micro (at this time Texas Instruments), NXP and many other manufacturers. These microcontrollers are very standard in the middle of embedded engineers and are used voguish various applications from automotive industry to hobby projects.

AVR

This is solitary of the mainly fashionable microcontroller families from Atmel. It is furthermore very popular in the middle of hobby engineers and it is used in many projects from uncomplicated LED controllers to knotty interaction campaign. The RISC architecture offers fast execution and low power consumption. Development tools are presented pro free of charge which is a lofty bonus for electronics enthusiasts. AVR is a dictate competitor to computer chips PIC. a quantity of be in support of something AVR, others like AVR. near is refusal unambiguous winner. Both families masterpiece well. It is up to the developer/programmer pardon? he like or else prefers.

PIC

This is a leading microcontroller type from chip. PICs are to be had featuring in very unimportant letters with just the minority pins and too since powerful 32-smidgen microcontrollers with many peripheral modules and I/O pins. They are very well-liked in the company of hobby engineers--in hobby projects you long for become aware of either AVR or else PIC.

8051

This is a very old 8-morsel microcontroller architecture with the intention of has managed to live on representing new than 30 years. Many brilliant compilers, a luck of code examples and austere development has contributed to the popularity of this species. This meat is still used featuring in many contemporary microcontrollers from Silabs, NXP, Atmel and many other microcontroller manufacturers. It is very likely with the aim of the 8051 is the nearly everyone widely used core in embedded applications. Of way, many new-found designs desire probably habit ARM before nearly other difficult architecture, but since of popularity of the 8051 everyday during the ancient times and availability of development tools it is still used in many applications.

widespread microcontrollers are popular principally as of availability of inexpensive development tools and low prices of strategy. as hobby engineers start using individual line they develop used to it and it is very likely so as to they willpower use it soon in the field of a skilled project. While PIC and AVR microcontrollers are deeply used in hobby projects, ARM has prevailed in the licensed embedded humanity.

Two Colour LED Light Bar Circuit

This circuit is a circuit run on alternating two insignia.It uses the 2-color LED with a built-participating in 3-pin single.This preference look for away the glow of every LED until the base.It turns alternating to one more color.In in the least way to the moon on the moon essential end, afterward the LED end of the first LED.Circuit consists of, nand gate ic.Two 10 Counter circuits IC, and IC JK flip washout.

company of the circuit is not speaking into 3 sets.It is a solid of gesture generators, a set of parade and control.Set the signal generator is IC1a,and IC1b quantity 4011 is a signal generator.The R2, R3, C2 determine the frequency generated.The hint is fed to a set of impressions is the figure 4011 IC2 and IC3.The 10 counter circuits to output to the LED, and Is the same, but the effort should ensue performed individual by the side of region. Therefore, the show from pin 11 of IC 2 and tested pro D2 and D3,To pin 3 of IC4.The integrated circuit IC 4 is a JK flip slump is connected to a T flip flop.The signal input pin 3 and pin 1 is the output hint at.Which sends a signal to the Reset IC either obstruct working.IC4 on the anniversary, it want output the originally moment in time, happening contrast to pin1.IC3 progress to handiwork, IC2 stopped.

IC2 is controlled by signals from pin 1 of IC4, to IC1c.earlier to control IC2.The IC3 is connected to pins 1 through D1 to the control again.

Eight Band Sub Woofer Graphic Equaliser

Your sub is installed and set up as best you can, but you cant quite get it to sound right. Some frequencies are too prominent, while others seem subdued. If this sounds familiar, then this equaliser is what you need to fix it. It is not a panacea, and will not cure an impossible room, but the majority of lumps and bumps in the subwoofer response will respond very well to an equaliser as described here.

The unit is an 8 band variation on the expandable equaliser described in the Project Pages, and is dedicated to its task. Boards can be stacked to get more bands if desired, but the arrangement shown will be quite sufficient for most installations.

Eight

Photo of Completed P84 Board

The equaliser is a constant Q design, so unlike most "ordinary" equalisers, it does not have a very low Q at low settings of boost and cut. This is a major problem with the standard (graphic) equaliser circuit, and is completely avoided by the constant Q version. Using the Multiple Feedback Bandpass design, these filters can be designed for any (reasonable) frequency and Q desired. As a 1/3 Octave equaliser, the filter Q should be 4.3, but I have deliberately lowered this to 4 for this design to allow a little overlap.

While there will always be "that" room which defies all attempts to make anything sound halfway decent, this EQ will dispose of the majority of problems likely to be encountered.

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.

Very Simple Pre Regulator

Present desire be there many period anywhere it is considered necessary to waste the P05 supply module from a upper voltage source. intended for case, if you lack to add balanced inputs to a power amplifier, next you need a +/-15V supply, but the amps supply voltage willpower survive much too far above the ground for the manager ICs.

This project is roughly speaking to the same extent unpretentious as they take place, and is very economical to build. It is designed in support of exactly this reason - to reduce the amplifier supply voltage to a safe significance for controller ICs.

The circuit it is very down-to-earth indeed. You desire need to make it to a hardly any simple calculations to determine the resistor value, but this is explained beneath.

The circuit made known uses the 24V zener diodes (D1 and D2) to adjust the output voltage to a unimportant under 24V. This is a seamlessly safe input voltage in favor of standard 3-terminal regulators, and using this circuit long for provide even better guideline and supply clamor rejection at that time typical. Using MJE3055 and 2955 transistors will allow for supply voltages up to 70V quite safely, but they will need to take place mounted on a heatsink (with insulating washers).

The single-mindedness of R5 is to detach the foremost power amplifier ground from the supply, to prevent hum loops. The 10Ω resistor revealed motivation be fine in lieu of the vast majority of applications, but might need to remain untouched. This is up to you to research with if essential. I hint at so as to R5 ought to be 1W. R2 and R4 may perhaps be 1/4W before 1/2W resistors, and 1W zeners are recommended.

The lone calculation is to determine the regard in support of R1 and R3. original, quantify the power amp supply voltage (V1). The resistor value is calculated to provide a top figure zener current of 20mA, and this hope against hope ensure sufficient found current for the pass transistors representing up to 100mA before so output current by the side of ±15V.

V2 = V1 - 24 (someplace V1 is amplifier supply voltage, and a 24V zener is used)

R1 = R3 = V2 / 20 (R1 and R3 morals are arrived kΩ)

P = V2² / R1 (P is power dissipation of R1 and R3 in mW)

consent tos begin to have a supply voltage of ±56V meant for an pattern calculation ...

V2 = 56 - 24 = 32V

R1 = R3 = 32 / 20 = 1.6k (practice 1.5k)

P = 32² / 1.5 = 680mW = 0.68W (use 1W)

The dissipation in Q1 and Q2 could as well be located calculated, but you need to know the current drawn by the outdoor circuits. on behalf of instance, if the external circuitry draws 50mA, the transistor power dissipation is ...

Pt = V2 * Iext = 32 * 50 = 1600mW = 1.6W (it self-control need a slight heatsink)

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 LM4765 has a sophisticated thermal protection scheme to prevent long-term thermal stress of the device. When the temperature on the die reaches 165°C, the LM4765 shuts down. It starts operating again when the die temperature drops to about 155°C, but if the temperature again begins to rise, shutdown will occur again at 165°C.
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

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.

LED

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.

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 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

IC TLC271 Single supply Function Generator

The circuit has both square-wave and triangle-wave output. The left section is similar in function to a comparator circuit that uses positive feedback for hysteresis. The inverting input is biased at one-half the Vcc voltage by resistor R4 and R5. The output is fed back to the non-inverting input of the first stage to control the frequency.
The amplitude of the square wave is the output swing of the first stage, which is 8V peak-to-peak. The second stage is basically an op amp integrator.

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