PIR motion sensor questions

Goofball

Hi guys I'm a little knew to robotics and electronics in general. So forgive if I come across as an idiot.

I'm trying to build a simulation claymore that is motion activated. I'm using the·PIR module seen here. http://www.parallax.com/Store/Sensors/ObjectDetection/tabid/176/CategoryID/51/List/0/Level/a/ProductID/83/Default.aspx?SortField=ProductName%2cProductName
I just have a few question as far as the wiring and operation of the sensor

1. It says that the maximum voltage is 5V, now would it damage it at all if I ran at 6v instead since that's the power supply I'm using.
2. Do I have to use a micro controller with the sensor in order to activate a simple circuit, or could I wire the output pin directly into the circuit
3. How high would the output voltage be if 5v or 6v was used as a power source.

Thanks in advance for any help.
·

Mike Green

1) The documentation says 5V. If it were designed to work up to 6V, they would likely have said it. Assume it can be damaged if operated at 6V.

2) Read the documentation. The output can be used to trigger an external transistor switch. I wouldn't try to drive anything else directly.

3) For a 5V supply, the output is likely to get up to about 4.4 to 4.6V. Anything over about 1.2V is normally considered to be a logic true value for some circuits. Other circuits assume that anything over 1/2 the supply voltage is a logic true output.

Goofball

thanks alot, like I said I'm kinda new to this stuff and just want to make sure I fully understand how it works.

Goofball

Ok new problem, I hooked the sensor up and the signal output is giving a constant .5v reading according to my multimeter and it doesn't react at all when I move infront of it.

·My power supply is 4 nimh AAAs (4.8v total).

Mike Green

A 0.5V reading is a logic zero. Make sure the sensor is jumpered to stay on with multiple triggers. The default (I think) is to put out a separate pulse every time it's triggered and the multimeter can't react quickly enough for you to see the pulses.

Check the power supply voltage. You really need 5V. If the batteries are a little low, the sensor may not work.

william chan

I measured the output logic high and I got only 3.6v with a 5V regulated power source.

My question,

How many milliamps can the output safely supply when the output is high?

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