Quote Originally Posted by Clive S View Post
What that means is that the switch can supply 300mA try putting a mA meter in circuit and see what you get.
The 300mA is the current the switch can sink. Inside the sensor is a 10K resistor between the supply and output. AT 24v supply it means that it will source 2.4mA at that voltage. For all practical purposes you can regard the output of these sensors as though it is the NO contact of a relay, with the common of the relay being connected to GND.


If you see this page IGNORE IT ! it is wrong, misleading,confusing and confused. http://www.marchantdice.com/worldofc...tch_wiring.pdf

It sounds as though you have a faulty sensor if the power supply buzzes, possibly due to miswiring in the past.




This has all been discussed before.