Thread: PIR Power 12V-3V Need Help

Tweet

I have a PicoBoo prop controller and I want to attach a PIR sensor as a trigger. I found this one at Radio Shack for a reasonalble price, but the only issues is it takes a 3-5V power range and the controller provides a 12 v source. Can I use a resistor to lower the voltage or do I need a transformer? I am assuming these are DC voltages

RadioShack.com - Cables, Parts & Connectors: Component parts: Digital ICs & micro controller: PIR Sensor Module

what you need is a voltage divider circuit, google for 'voltage divider' and you will find what you want, alternatively you can use a voltage regulator to regulate the 12V down to a lower voltage

Would this work? RadioShack.com - Cables, Parts & Connectors: Component parts: Transistors & analog ICs: Adjustable-Voltage Regulator LM317T

looks good, here's a handy web page for it, that explains how to configure the resistors...however, if you went for a fixed voltage regulator it would be a lot easier

http://ourworld.compuserve.com/homep...den/page12.htm

Ok so the next question is the Voltage Regulator has three terminals can I assume that one is for Voltage in, one it the ground and the other voltage out?

Read first ask question second...duh! Thanks

Originally Posted by scareisburg

Ok so the next question is the Voltage Regulator has three terminals can I assume that one is for Voltage in, one it the ground and the other voltage out?

look at the link in my last email, there are a few components you need to add to adjust the voltage.

5VDC regulators are very common, you may be better of using one of those instead of this adjustable one

First I'm going to see if I can find a similar PIR that accepts 12V. Like electricty I take the path of least resistance

PIR Sensor Module

This one accepts 12V but has four terminals, why?

Yikes that one has three this one has four Compact PIR Sensor Module

Originally Posted by scareisburg

First I'm going to see if I can find a similar PIR that accepts 12V. Like electricty I take the path of least resistance

PIR Sensor Module

This one accepts 12V but has four terminals, why?

I would guess

GND
+V supply
Normally open output
Normally closed output

or

GND
+V supply
dry contact in
dry contact out