Switches for Electronics

Almost all electronic circuits are controlled. Primarily by use of some kind of switch.

LED off while in pushbutton switch controlled circuit schematic diagram by electronzap
LED off while in pushbutton switch controlled circuit schematic diagram by electronzap
  • Many momentary switches, such as push button, are normally open (off) when left alone.
    • Pressing the button closes the switch, and thus the circuit, which usually turns it on.
LED on while in pushbutton switch controlled circuit schematic diagram by electronzap
LED on while in pushbutton switch controlled circuit schematic diagram by electronzap
  • Normally closed momentary switched will be closed (on) when left alone. You have the press the button to open it (turn it off) if it is a pushbutton switch.

High side versus low side:

High side versus low side switching circuit schematic examples diagram by electronzap
High side versus low side switching circuit schematic examples diagram by electronzap
  • Switch is high side when it is closer to the positive supply than the negative supply in relationship to the load that is in series with it.
  • Switch is low side when it is closer to the negative supply than the positive supply in relationship to the load that is in series with it.

Magnetic Reed Switch:

Magnetic Reed Switch electronics demo circuit schematic with LEDs
Magnetic Reed Switch electronics demo circuit schematic with LEDs

Transistor Switch Circuits:

NPN bipolar junction transistor BJT switch circuit introduction schematic diagram by electronzap
NPN bipolar junction transistor BJT switch circuit introduction schematic diagram by electronzap

 

PNP Bipolar Junction Transistor BJT switch schematic diagram for learning electronics lesson 0013 by electronzap
PNP Bipolar Junction Transistor BJT switch schematic diagram for learning electronics lesson 0013 by electronzap
N channel enhancement mode MOSFET 2N7000 switching LED schematic diagram pin layout by electronzap
N channel enhancement mode MOSFET 2N7000 switching LED schematic diagram pin layout by electronzap
P channel enhancement mode MOSFET switch circuit schematic diagram BS250 pin layout by electronzap
P channel enhancement mode MOSFET switch circuit schematic diagram BS250 pin layout by electronzap
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