To begin with, the circuit in this article shows a simple high voltage mini audio amplifier which uses one UJT transistor Q1 2N2646 and one power transistor Q2 AC187. This UJT Based High Voltage Mini Audio Amplifier Circuit works with a high supply of around +125V and it can drive a small 4 ohm speaker […]
Transistor Circuits
Transformerless Audio Amplifier Circuit using Germanium Transistor
In this post we will understand about a simple power amplifier circuit using AC176 and AC126 type PNP germanium transistor in OTL (output transformer less) design. Also, this circuit gives audio power directly to speaker without output transformer, it is low voltage circuit and works with 9V battery. Therefore, the circuit design is easy and […]
Low Impedance Driver Circuit using BJT Transistor
To begin with, this circuit shows a small audio amplifier which uses two BJT NPN transistors, they works with low impedance output like small speaker or earphone. Also, the circuit takes weak input signal and makes it stronger and runs on DC supply from +6V to +18V, as the circuit is simple, low cost and […]
Transistor Based Audio Amplifier Circuit
A Transistor Based Audio Amplifier Circuit is a simple and useful audio circuit that increases weak audio signals into a louder sound signal. This circuit uses four transistors, namely two BC547 NPN transistors and two BC557 PNP transistors, because of its simple design, students and beginners can easily understand and build it. Moreover, this circuit […]
PIR Sensor Based PNP Switching Circuit for Output Control
In this tutorial, circuit uses a PIR sensor to control an output load through transistor switching, but the main purpose of this circuit is to turn ON the output when motion is detected and when PIR sensor detects motion, it gives a trigger signal After that, the NPN transistor and PNP transistor work together as […]
5V 4A Power Supply Circuit using IC 7805 and Parallel Transistors
In this post, the below designed circuit gives a stable 5V DC output with high current up to 4A which uses the 7805 voltage regulator IC and multiple TIP41C transistors connected in parallel, because the normal 7805 IC alone gives around 1A current and we add external power transistors to increase the output current. Moreover, […]