Pir Module

Right, I brought a passive infrared sensor line fast.
http://www.rapidonline.com/Electronic-Components/Sensors/Pir-Sensors/PIR-Module-with-lens/81565/kw/PIR
The specification of the latter is in PDF format on the page. There are three tracks: a power, ground and output. I used it as an NPN transistor, as I assume the output rail voltage and would thus be used to open a CBC transistor 548B and so on. However, when using a multimeter, I get negative voltage raila On the specifications it says it uses "shape NPN open collector output (active low):" A. Any help would be amazing right now, thank you in advance.

Dan

Simply, an output OC is equivalent to an NPN transistor whose emitter is grounded and the collector is shown in output by itself. When the circuit behind the transistor is "active", it puts a positive signal at the base, "closure" of the transistor, or pulling the output line to ground. When the circuit is "inactive", the output is "open", or just floats.

You can use an OC output in two ways.

First, is to sink a load like a relay coil LED or small, the other end connecting to the positive rail.

The second is to take the OC output power rail with a resistance of 10K or more. This will give a logic signal for further processing.