In general, electrical signals are transmitted from one circuit to another circuit using various components or mediums. If we consider the television system operated using IR, then the infrared remote which consists of IR emitter is used to transmit electrical signal from remote circuit to the TV internal circuit. Similarly, every remote operated system uses either RF or IR or laser or etc., for transmitting electrical signals from one circuit to another circuit. In this article, let us discuss about Opto isolator circuit working and applications. [Read more…]

PNP and NPN Transistor

NPN and PNP transistors are bipolar junction transistors, and it is a basic electrical and electronic component which is used to build many electrical and electronic projects. The operation of these transistors involves both electrons and holes. The PNP and NPN transistors allow  current amplification. These transistors are used as switches, amplifiers or  oscillators. Bipolar junction transistors can be found either as  large numbers as parts of integrated circuits or in discrete components. In PNP transistors, majority charge carriers are holes, whereas in NPN transistors, electrons are the majority charge carriers.  But, field effect transistors have only one type  of charge  carrier.  [Read more…]