free schematics

 An oscillator is a system or device that oscillates, or moves back and forth, between two states or conditions. Oscillators can be found in...

 An opto-coupler, also known as an optocoupler, opto-isolator, or photocoupler, is an electronic device that uses a light-emitting diode (LE...

  An audio amplifier is a device that increases the strength of an audio signal. It is commonly used to drive speakers or headphones, and ca...

 A transistor is a type of semiconductor device that is commonly used to amplify or switch electronic signals. It is made up of three layers...

What is used for amplification of signals?  There are several devices and circuits that can be used for amplification of signals, including ...

Zener diodes are used in electronic circuits for several reasons: Voltage regulation: Zener diodes allow current to flow in both directions ...

reference Equivalentes application Features 2n3904 NPN Silicon BC 174, BC 182, ...