3 Input mic mixer circuit

john April 7, 2010 18 Comments
Description. Here is a simple 3 input mic mixer circuit using the popular uA 741 ICs. Four 741s are used here.IC1, IC2, IC3 are used as preamplifiers. They produce a gain of around 40 decibel to the individual input...
read more

Two transistor tone controller

john April 7, 2010 17 Comments
Description. Here is the circuit diagram of a simple two transistor tone controller circuit. This circuit is based on the famous Baxandal tone control design. The transistor Q1 is wired an emitter follower to provide sufficient current gain and...
read more

2X15 Watt stereo amplifier using TDA4935

john April 7, 2010 24 Comments
Description. TDA4935 is bipolar stereo amplifier IC that can be wired as a 2X15W stereo amplifier or a 30W mono BTL amplifier. The IC also features built in circuitry for over load protection and over temperature shut down. Here...
read more

Stereo line driver circuit

john April 7, 2010 No Comments
Description. This is the circuit diagram of a low cost stereo line driver is given here. The circuit consists of only two transistors and few passive components. Each BC 109C transistor is wired as an emitter follower for driving...
read more

Audio monitoring system

john April 7, 2010 2 Comments
Description. Here is the circuit schematic of a simple audio surveillance system in which the transmitter will pickup sound from one location and the receiver at other location will reproduce it. The receiver and transmitter are connected by only...
read more

3 LED battery monitor circuit

john January 27, 2014 50 Comments
Are you not familiar with the basics of electronics? We have just opened an online store where 4 very good books on basic electronics have been kept for sale. You can read the reviews of these books and buy...
read more

Canary chirp generator

john April 7, 2010 1 Comment
Description. This is a simple electronic alarm circuit that imitates the chirping of a canary. The circuit is nothing but a Hartley oscillator with few more passive components added. As the capacitor C1 charges through the resistor R1 and...
read more

3 Band graphic equalizer circuit

john April 7, 2010 8 Comments
Description. Here is the circuit diagram of a simple 3 band graphic equalizer circuit using a single IC and few components. The IC used here is LF 351 which is a wide bandwidth single JFET operational amplifier. The high...
read more

Simple IR audio link

john April 7, 2010 101 Comments
Description. Here is a simple IR audio link that can be used to transmit audio signals up to 4 meters. The signal to be transmitted is applied to the base of Q1 via resistor R4.The transistor Q1 drives the...
read more