Darlington transistor is a well known and popular connection using a pair of bipolar transistor junction transistor (BJT), designed for operating like an unified “superbeta” transistor. The following diagram shows the details of the connection. Definition A Darlington transistor can be defined as a connection between two BJTs that allows them to form a single […]
Archives for 2019
How Varactor (Varicap) Diodes Work
A varactor diode, also called varicap, VVC (voltage-variable capacitance, or tuning diode, is a type of semiconductor diode which features a variable voltage-dependent capacitance on its p-n junction when the device is reversed biased. Reverse bias basically means when the diode is subjected to an opposite voltage, meaning a positive voltage at the cathode, and […]
Tunnel Diode – Working and Application Circuit
A tunnel diode is a type of semiconductor diode which features a negative resistance on account of a quantum mechanical effect known as tunneling. In this post I have explained the basic characteristics and working of tunnel diodes, and also a simple application circuit using this device. We will see how a tunnel diode could […]
5 Best IC 555 Oscillator Circuits Explored
In this post I have explained how to build and optimize 5 useful IC 555 oscillator circuits, whose waveforms can be further enhanced for generating complex sound effects. Overview The basic mode that is normally employed for making IC 555 oscillators is the astable circuit mode. If we look at the astable circuit shown below, […]
Anti Spy RF Detector Circuit – Wireless Bug Detector
A anti-spy or bug detector circuit is a device that detects hidden wireless electronic devices such as wireless microphones, spy cameras, Wi-Fi devices, GPS trackers or any gadget that emits some kind of radio frequency (RF). The proposed design can be specifically used as: Overview Also called anti spy RF sniffer, these are usually used […]
How Transformers Work
According to the definition given in Wikipedia an electrical transformer is a stationary equipment that exchanges electrical power across a couple of closely wound coils, through magnetic induction. A constantly altering current in one winding of the transformer generates a varying magnetic flux, which, consequently, induces a varying electromotive force over a second coil built […]