Frequently Asked Question

Output load of PNP/NPN Switches.
Last Updated a year ago

Tilt/Acceleration switches are often connected to a PLC or to a relay for controlling the safety of a machine or any other applications. Want to know how it works exactly? Please read here.

The switch output can be made by using a PNP/NPN transistor, please read "Working of Transistor as a Switch" to learn more details.

Our first generation tilt switches can withstand a max load current of 150mA continuously and 250mA for max. 10 seconds. For a 2-axes tilt switch, there are 2 independent switching outputs, each output can withstand 150mA but not at the same time. From our tests and feedbacks from the market, we know this model is not 100% robust when large current is used. Therefore we decided to redesign this model.



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SmartFETs are introduced to the new generation tilt switches, which ensures that our sensor can withstand 150mA for both outputs simultaneously.

The connection of the load depends on the output type. PNP sensors need a pull-down resistor, which should be connected between the output and the GND.

It is better not to share the Sensor GND with any load GND over longer wiring when this load GND carries e.g. motor currents and may be flagged as "dirty". Consider a star gnd configuration to minimize hard to diagnose behavior.

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NPN sensors need a pull-up resistor, which should be connected between the output and the Vcc For testing the sensor, you can use a 5K resistance as the load. If the resistor is missing, you will read a wrong output.
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Reference:

https://www.electronicshub.org/mosfet-as-a-switch/

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