Page top

Lead Contents

FAQ00379 of Photoelectric Sensors FAQ

FAQ No. FAQ00379

Primary Contents

Question

What is the difference of NPN transistor output and PNP transistor output of the sensor?

Answer



(1) NPN output type is used when connecting a load between power supply + and sensor output terminal.

(2) PNP output type is used when connecting a load between sensor output terminal and power supply -.

This type is used a lot in Europe from the viewpoint on safety because the load is not driven even if somewhere of the wiring connected with the sensor output terminal is short-circuited with power supplies in some factors.

(3) The following is output circuit diagram of the E2E as typical.