A variety of small school projects can be built using just two transistors. This compilation includes a collection of practical and fascinating circuit ideas using just a few number of parts. Any small signal transistor can be used in the proposed two transistor circuit, such as BC547, 2N2222, 2N2907, BC108, BC107, TIP32, TIP31, 188, 8050, […]
Transistor
Match Transistor Pairs Quickly using this Circuit
In many critical circuit applications, like power amplifiers, inverters, etc it becomes necessary to use matched transistor pairs having identical hFE gain. Not doing this possibly creates unpredictable output results, such as one transistor getting hotter than the other, or asymmetrical output conditions. By: David Corbill To eliminate this, matching transistor pairs with their Vbe […]
Accurate Transistor Tester Circuits Explored
In this article we talk about a few simple yet accurate transistor tester circuits which can used to identify whether a transistor is good or bad. Note: Please test *only* BJTs and MOSFETs (enhancement or depletion) with these circuits. Simple Good/Bad Transistor Checker using a Single LED Do you have a lot of strange old transistors […]
Simple Transistor Diode Tester Meter Circuit
In this post I have explained how to make a simple yet efficient transistor/diode tester circuit, that will not only test the quality of a BJT, but will also help to identify whether it is is an NPN or a PNP. The circuit was designed and contributed by Mr. Henry Bowman. Circuit Operation Referring to […]
Semiconductor Tester Circuit [LED, Transistor, SCR Tester]
The semiconductor tester circuit I have explained below performs continuity tests on SCRs, bipolar transistors, and diodes. How the Circuit Works A squarewave oscillator with a frequency of about 350 Hz is produced by a couple of IC 4049 gates, U1a along with U1b, R1, R2, and C1. The complementary outputs required for testing both NPN and […]
Single Transistor LED Flasher Circuit
It is possibly the smallest LED flasher to date, which is able to flash an LED ON/OFF infinitely using a single transistor, a resistor, and a capacitor. Can you imagine making a great looking LED flasher or blinker with just a single transistor and a couple of other passive parts? That’s exactly what I have […]