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
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 […]
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 […]
How to Replace a Transistor (BJT) with a MOSFET
In this post I have explained the method of correctly replacing a BJT with a MOSFET, without affecting the final outcome of the circuit. Introduction Until MOSFETs arrived in the field of electronics, transistors or BJTs to be precise ruled the power switching circuits and applications. Though even Bipolar Junction Transistors (BJTs) can not be […]
How to Use Resistors with LED, Zener and Transistor
In this post I have explained how to use resistors while designing an electronic circuits using LEDs, zener diodes, or transistors. This article can be very useful for the new hobbyists who normally get confused with the resistor values to be used for a specific component and for the desired application. What is a Resistor […]
Bipolar Transistor (BJT) – Construction, and Operational Details
A bipolar transistor or a BJT is a 3 terminal semiconductor device which is able to amplify or switch small signal input voltages and currents to significantly larger output signal voltages and currents. How Bipolar Junction Transistor BJTs Evolved During 1904–1947, the vacuum tube was unquestionably the electronic device of great curiosity and growth. In 1904, […]