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 […]
Working
Triacs – Working and Application Circuits
A triac can be compared to a latching relay. It will instantly switch ON and close as soon as it’s triggered, and will remain closed as long as the supply voltage remains above zero volts or the supply polarity is not changed. If the supply is an AC (alternating current), the triac will open during […]
Optocoupler Circuits, Working, Characteristics, Interfacing
OPTOCOUPLERS OR OPTOISOLATORS are devices that enable efficient transmission of DC signal and other data across two circuit stages, and also simultaneously maintain an excellent level of electrical isolation between them. Optocouplers become specifically useful where an electrical signal is required to be sent across two circuit stages, but with an extreme degree of electrical […]
Photodiode, Phototransistor – Working and Application Circuits
Photodiodes and phototransistors are semiconductor devices which have their p-n semiconductor junction exposed to light through a transparent cover, so that external light can react and force an electrical conduction through the junction. How Photodiodes Work A photodiode is just like a regular semiconductor diode (example 1N4148) consisting of a p-n junction, but it has […]
Reed Switch – Working, Application Circuits
In this post I will comprehensively explain about reed switch functioning, and how to make simple reed switch circuits. What is Reed Switch Reed switch also called reed relay, is a low current magnetic switch with a concealed pair of contacts that close and open in response to magnetic field near it. The contacts are […]
Diac – Working and Application Circuits
The diac is a two-terminal device having a combination of parallel-inverse semiconductor layers, which allows the device to be triggered through both directions regardless of the supply polarity. Diac Characteristics The characteristics of a typical diac can be seen in the following Figure, which distinctly reveals the presence of a breakover voltage in across both […]





