In reality a transistor is generally added to the circuit to provide enough power to control the relay, while a diode protects the transistor from the reverse voltage spike caused by cutting power ...

A ULN2803 Darlington transistor with base current controlled by the optocoupler drives the relay.

Many integrated circuits have undocumented features or abilities. This is one of them. The TLC555 output (pin 3) can sink a 100mA load to 1.28V. The open drain transistor reset (pin 7) can sink 100mA ...

Obviously, the function of muting circuits is to mute (kill) the audio signal. This can be done in a number of ways including switches, relay contacts, junction FETs, analog switches and bipolar ...

The relay itself can be triggered by a 9V battery via the transistor in the control circuit. Notice the protoboard in the image above.

A very simple but highly efficient combination lock circuit is shown in the figure. Any type of on/off switches can be used, varying from commercially available inexpensive types ...

As with many inventions, two people had the idea for an integrated circuit at almost the same time. Transistors had become commonplace in everything from radios to phones to computers, and now ...

Explains the principles of transistor switching circuits, highlighting their role in electronic computers. It contrasts transistors with vacuum tubes, emphasizing that transistors function as ...