How do you connect an output using NPN transistors?


This is not a standard type of output, so it may need to be explained to ensure that your connection is safe. At APEM, the CG series is a capacitive switch, the CP series is a piezoelectric switch and the IHS series is a pushbutton switch, but the output of all three series is based on NPN transistors.

Christophe Moreau Christophe
Switch Product Manager

Christophe joined APEM in 1996.
After deepening his product knowledge within the design department, he has been our Switch Product Manager and a member of the marketing team since 2011. 

Nicknamed “Switch Doctor”, he is APEM’s living encyclopedia. 

Christophe, APEM Switch Product Manager, guides you through.

For an output using NPN transistors, the charge must be connected between the output and the positive terminal of the power supply.

In practice, the output of these switches reflects the positive terminal of the default power supply. When the switch is activated, the output is grounded (negative terminal).

This type of switch therefore differs from a mechanical switch, which is often connected to reflect the positive terminal when activated.

Typical wiring diagram for NPN transistor series:

Always refer to the technical brochure of the series for the assignment of wires/outputs.


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