Electronic Circuits and Diagram-Electronics Projects and Design

Description. Here is the circuit diagram of a simple 3 channel audio splitter based on the IC NE5532. NE5532 is a dual internally compensated low noise opamp from Fairchild semiconductors. It has a high small signal and power bandwidth, making it well suitable for high quality audio applications. Here the IC1 is wired as a non inverting amplifier with a gain 3.The audio signal to be splited is applied to the non inverting pin of IC1 through the POTs R2 and R3.Capacitor C2 works as a DC decoupler and resistors R8, R9, R10 splits the output of the IC1 into…

Description. Many low pass filter circuits for subwoofer are given here and this is just another one. The circuit given here is based on the opamp TL062 from ST Micro electronics. TL062 is a dual high input impedance J-FET opamp which has very low power consumption and high slew rate. The opamp has excellent audio characteristics and is very suitable for this circuit. Out of the two opamps inside TLC062, first one is wired as the mixer cum pre amplifier stage. The left and right channel are connected to the inverting input of IC1a for mixing. The gain of first…

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 is also packed with a lot good features like fast slew rate, wide supply voltage range, high output current, high output voltage swing, thermal protection etc. The IC is available in TO-220 plastic power package and is well suitable for a variety of applications like…

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 IC also has a lot of good features like loud speaker protection, short circuit protection, low noise, low distortion etc. The circuit can be operated from a 12V DC single power supply and this makes it very useful in car audio applications. Circuit diagram. Notes….

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. LED is D1 is a power ON indicator and R1o is its current limiting resistor. Circuit diagram. Notes. Assemble the circuit on a good quality PCB. Switch S2 is the ON/OFF switch. Swich S1 can be used to select linear or contour mode. Supply voltage…

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 output) and has a power supply rejection ration (PSRR) of 85 dB. The IC requires very few external components and has a built in mute facility. The LM4780 is completely protected using their trademark SPiKe technology and has a signal to noise ratio greater than…

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 this concept I designed this circuit during 1981 to 1986 with lots of field trials and modifications, the design was frozen in 1986. I have assembled so many amplifiers for me and for my friends based on this design with various power levels. They are…

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 the four op-amps inside the IC LM348, IC1a, IC1b and IC1c are wired as non inverting amplifiers and they serve as the input amplifiers for the corresponding mic channels. The output of these three amplifiers are tied together and connected to the inverting input of…

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 to 15V DC and is extremely stable to capacitive loads. In the circuit capacitors C1, C3, C5, C7 and C9 are used to fix the resonance frequency of the corresponding bands. Capacitors C2, C4, C6, C8, C10 and C15 are the input capacitors and increasing…

Description. This simple tone control circuit is designed based on the famous Baxendall tone control circuitry. The circuit given here can give a maximum cut or boost of around 12 dB at 10 KHz (treble) and 50Hz (bass). Also, both bass and treble can be independently adjusted. Transistor Q1 (BC109) and its associated components (R1, R2 and R3) form an emitter follower which is the input stage. The voltage gain of this input stage is around 1 and it has an input impedance of around 225K ohms. The output of the input stage is coupled to the passive Baxendall circuitry…