Electronic Circuits

Amplifier Circuits

15W Class B Audio Amplifier

Audio Amplifier Circuit – 15 Watts The circuit below is  of a  15 Watts Class B audio amplifier circuit  designed using a dual Op-amp and transistors. Description : The circuit shown here is of a simple Class-B audio amplifier based on opamp TL082, transistors TIP41 and TIP42. LM833 is a dual opamp with high slew rate […]

Amplifier Circuits, Audio Circuits

Active crossover circuit

Active Crossover Circuit Given below is an Active crossover circuit suitable for HiFi audio systems using LM833, the dual operational amplifier. Description: Crossover circuits are of two types, active and passive. Passive crossover circuit uses passive components only and they are very simple, but they waste a considerable amount of energy and also induce distortion.

Amplifier Circuits, Audio Circuits

Bridge Amplifier using TDA 4935

Bridge Amplifier The circuit given below is a bridge audio amplifier circuit using IC  TDA4935. Description : TDA4935 is 2x15W high quality audio amplifier IC from Siemens. The IC can be used in stereo mode or bridge mode. In stereo mode it can deliver 15W per channel and in bridge mode it can deliver 30W

Motor Related

H Bridge motor control circuit using L298

H Bridge Motor Control Given below is an H bridge motor control and  driver circuit using IC L298 Description : A bidirectional H bridge DC motor control circuit is shown here. The circuit is based on the IC L298 from ST Microelectronics. L298 is a dual full bridge driver that has a wide operating voltage range

Amplifier Circuits, Audio Circuits

HiFi headphone amplifier circuit

Description. LM4880 is HiFi dual audio amplifier IC from National Semiconductors. This IC is specifically designed to produce high quality audio output with a minimum number of external components.LM4880 is capable of delivering 250mW per channel into an 8 ohm load. The IC has 0.1% THD and has a supply voltage range of 2.7 to

Motor Related

Motor driver using TC4424

Description. The circuit shown below is of a DC motor driver circuit based on the IC TC4424 from Microchip. TC 4424 is a dual MOSFET driver that can be used in a variety of applications like SMPS, pulse transformer drivers, line drivers, motor drivers etc. The speed and of direction rotation of the motor depends

Motor Related

H bridge motor driver circuit

Description. The circuit given here is of a simple H bridge motor driver circuit using easily available components. H Bridge is a very effective method for driving motors and it finds a lot of applications in many electronic projects especially in robotics. The circuit shown here is a typical four transistor H Bridge. The diodes

Power Supplies

10V switching regulator using LM5007

Description. The circuit diagram shown here is of a 10V switching regulator based on the LM5007 from National Semiconductors. The LM5007 is an integrated step down switching regulator which has all necessary systems required for making a cost effective and reliable switching regulator circuit. The IC is available in MSOP-8, LLp-8 packages and has a

Audio Circuits, Automotive Circuits

20W audio amplifier using LM1875

Description. This is just another 20W audio amplifier circuit , but this time based on the LM1875 audio amplifier IC from National Semiconductors. With a 25V dual power supply LM1875 can deliver 20W of audio power into a 4 ohm speaker. The LM1875 requires very less external components and has very low distortion. The IC

Amplifier Circuits, Audio Circuits

20W audio amplifier using TDA7240

Description The audio amplifier shown here is based on the TDA7240 IC from ST Microelectronics. The TDA 7240 is an integrated audio amplifier IC that can deliver 20 watts of audio output power into a 4ohm load. The IC has minimum external parts count and is available in the 7 pin compact Heptawatt package. The

Audio Circuits

Stereo preamplifier with tone control

Description. Here is the circuit diagram of an excellent stereo preamplifier with tone control using the IC TDA1524 from Phillips. The IC requires very few external components, has very low noise and has a wide power supply voltage range.  POTs R1 to R4 can be used for controlling the volume, balance, bass and treble respectively.

Power Supplies

30V / 3A adjustable regulator using LM723

Description. Here is the circuit diagram of a 30V/3A adjustable regulator using the LM723 IC from the National Semiconductors. LM723 is an integrated series regulator whose output voltage can be adjusted between 2V and 37V. The IC by itself can deliver an output current of 150mA and the maximum input voltage to the IC is

Television Related

TV antenna booster

Description. The circuit shown here is of a TV antenna booster based on the transistor BF180. The circuit operates in the UHF band and has a gain of 15dB. Capacitors C2,C3 C4 ,C5 and inductors L3, L4 forms a UHF band pass filter. The input signal is fed to the emitter of Q1 through this

Lighting Circuits

Mains operated blinking LED

Description. The circuit diagram of a blinking LED that can be operated from the mains supply is shown here. The working of this circuit is as follows. When mains power is switched ON the capacitor C2 charges through resistor R1 and diode D1. When the voltage across the capacitor becomes greater than 32V ( break

Amplifier Circuits, Audio Circuits

2 x 60 W audio amplifier circuit

Description. The circuit diagram shown here is of a 2 x 60 Watt stereo amplifier based on the LM4780 from National Semiconductors. LM4780 is a superb audio amplifier IC capable of delivering 60W Rms power output / channel into 8 ohm speakers. The LM4780 has very low total harmonic distortion (less than 0.5% at full

Test & Measurement Circuits

Capacitance meter using LM2917

Description. The circuit diagram of a simple capacitance meter using IC LM2917 is shown here. The LM2917 is a high gain monolithic frequency to voltage converter IC from National Semiconductors. Even though the main application of LM2917 is in tachometers, it can be also used for a variety of applications like this. Capacitance values from

Power Controller Circuits, Power Supplies

Simple DC power delay circuit

Description. The circuit diagram shown here is of a simple DC power delay circuit that is based on an SCR. This circuit is a very handy one and can be employed in many applications. The working of this circuit is very simple. When the input power is applied the capacitor C2 charges through resistor R2

Amplifier Circuits, Audio Circuits

Motional feed back amplifier

This versatile amplifier circuit is designed and submitted by Mr Seetharaman Subramanian from Chennai . The full credit of this article goes to him and we are very proud to publish this fabulous circuit here. Seetharaman’s description about the circuit. This concept has appeared long back in Practical Electronics a UK based Magazine. Based on

Audio Circuits

3 input microphone preamplifier

Decription. The circuit given here is of a three input mic mixer cum preamplifier using the IC LM348. The LM348 is a high gain, internally compensated quad operational amplifier with a class AB output stage. The IC has very low input supply current drain (0.6mA/ opamp) and operates from a dual power supply. Out of

Audio Circuits

5 band graphic equalizer using LA3600

Description. The graphic equalizer shown here is based on the IC LA3600 from Sanyo Semiconductors. LA 3600 is a single integrated single Op-amp, 5 band graphic equalizer IC which is very suitable for applications like portable stereo, radio sets, home theater systems, car audio systems etc. The LA3600 can be operated from anything between 5

Remote Circuits

FM remote Encoder/Decoder

Description. Here is the circuit diagram of an FM remote encoder/decoder using the ICs RF600E and RF600D. These devices are designed to provide a high level of security and operates from anything between 2 to 6.6V DC. Various electronic circuits like remote control systems, remote alarm systems, anti theft alarms etc can be implemented using

Audio Circuits

Low cost Mic Mixer

Description This is the schematics of a low cost mic mixer that can be assembled from the components in your junk box.This two channel mike mixer is designed for handling high impedance dynamic microphones.Transistor Q1 can be any general purpose pnp transistor like BC177 or BC157B. Resistor R5 biases the transistor while R3 and R4

Three phase circuits

Three phase auto changer circuit

Description. The circuit given here is designed by Mr.Seetharaman V.S (seethasub@hotmail.com) from Chennai. Seetharaman’s comments about the circuit: This circuit is a modification of  High & Low voltage cut-off with delay& alarm circuit  appeared in Circuits today, which I have tried and found to be quite reliable. You can adopt this circuit with small modification.

Audio Circuits, USB Circuits

USB sound card

Description. Designing and building a USB sound card is no longer a head ache because we have got the PCM 2702 integrated circuit from Texas Instruments. The PCM2702 is an integrated 16 bit digital to analog converter that has two digital to analog output channels. The integrated interface controller of PCM2702 is compliant to the

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