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 […]
Transistor
Easy Two Transistor Circuit Projects for School Students
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 Relay Driver Circuit with Formula and Calculations
In this article we will comprehensively study a transistor relay driver circuit and learn how to design its configuration by calculating the parameters through formulas. Importance of Relay Relays are one of the most important components in electronic circuits. Especially in circuits where high power transfer or mains AC load switching is involved, relays play […]
Transistor Multivibrator Circuits [Astable, Bistable, Monostable]
A transistor or BJT multivibrator is a two-stage switching circuit that is configured in a cross-coupled manner. This allows each of the active BJT stages to be regeneratively cross-coupled with the other BJT stage, so that one switches ON when the other switches OFF, and vice versa. This cross-coupling may be set up to switch either a […]
Variable Voltage, Current Power Supply Circuit Using Transistor 2N3055
In this post I have explained how to make a simple variable power supply circuit using transistor 2N3055 and some other passive components. It includes variable voltage and variable current feature, fully adjustable. Main Specifications 1) Adjustable from 0-30V, 0-60V, and 0-100V, and 500mA to 10 Amp as per user preference 2) Short Circuit Protected […]
Unijunction Transistor (UJT) – Comprehensive Tutorial
A unijunction transistor is a 3 terminal semiconductor device which is unlike a BJT has only a single pn junction. It is basically designed to be used as a single-stage oscillator circuit for generating pulsed signals suitable for digital-circuit applications. UJT Relaxation Oscillator Circuit The unijunction transistor could be typically wired in the form of […]