Help with a project???

I want to build a motion alarm, but I dont have my microcontroller stuff yet. I have a parallax PIR sensor module that I want to use for the sensor obviously. I have tons of other stuff, except avr stuff. does anyone know how I can set it up so it would work without a microcontroller?

Your PIR should have terminals for power and a dry contact closes on motion, you could connect a small PCB relay to control a bell or siren. Be sure not to exceed the current limit on the PIR

ghost309,

Is this you PIR? :

https://www.electro-tech-online.com/custompdfs/2008/03/PIRSensor-V12.pdf

Datasheets tell you a lot.

The output is a voltage...0V=no motion...+5v=motion.
You can use this to drive a transistor base (through a resistor) or a mosfet gate.
Are you familiar with using these?
They can in turn, turn on your alarm lights, buzzers,...

Ken

moffet, i had a 555 timer pulsing to a 4017 decade counter, it was working fine until i wanted to turn a pcb relay on to control larger watt lamps, i used one mosfet and nothing happened, so the electrician in me said paralell the mosfets and it worked, my question is what would you use so paralelling wasnt needed ? and also, about how much current can a mosfet typically put out, eventually i want to design a circuit with components for wig wagging like an emergency vehicle, i did it with led's but i need something that switches fast and not a pcb relay because electro mechanical would never switch that fast, i'd like your or anyone else's input, thanks jim

KMoffett said:

ghost309,

Is this you PIR? :

https://www.electro-tech-online.com/custompdfs/2008/03/PIRSensor-V12-1.pdf

Datasheets tell you a lot.

The output is a voltage...0V=no motion...+5v=motion.
You can use this to drive a transistor base (through a resistor) or a mosfet gate.
Are you familiar with using these?
They can in turn, turn on your alarm lights, buzzers,...

Ken

Click to expand...

Yes, that is my PIR, and no, I am not familiar with using those. Could you explain them a little bit?

First...jbelectric777...it's not considered proper to pop into a thread on a specific subject/circuit with an entirely different problem. Well it may have to do, in this case, with output drivers, but your circuit will probably divirge from ghost309's quickly. If you start a new thread, I'll be happy to jump in there.

ghost309... The output of your PIR is considered a "logic level" signal. This can be put directly into a microcontroller's Inputs. The PIR's output can also act exactly like a microcontroller's output, so can drive output devices such as lights, buzzers, LEDs, relays, the way a µC would. Since this a Parallax device, I'm sure you are going with the Basic Stamp for a microcontroller. A quick look at their documentation list didn't show me what I wanted to show you. (though it's probably there). So, I'm going to direct you to an interfacing manual for a µC I'm more familiar with.

https://www.electro-tech-online.com/custompdfs/2008/03/picaxe_manual3.pdf

Go to the section on "Output device interfacing". These circuits are for the outputs of a microcontroller, but that will work as output drivers directly from your PIR. If you have specific devices you want to turn on and off, I'll help with the best driver. Overall that manual is a good basic read no matter who's µC your using.

Ken