Two PIR sensors to actuate one device

terry.shitcrumbs · 2015-09-09T07:42:26+00:00

Hi. I'm pretty sure that what I want to do is fine, but might someone with know ledge/experience of such matters please help by confirming? I want to rig up an outdoor device actuated by PIR sensors. There will only be one device, but I'd like to have it respond to either of two sensors, t o get broad area coverage. Is it as simple as wiring both sensor power outp uts to the supply terminals of the device? Clearly, the device will only dr aw the power that it wants to draw, regardless of whether one, other, or bo th PIRs are activated. However, I'm not 100% sure whether standard outdoor PIRs (e.g. from Toolstation) might be designed such that the output termina ls becoming live in the absence of PIR sensor activation would be a proble m. This circumstance would occur if only one PIR is activated, since both o utputs would be connected via the supply terminals on the device. Cheers. Terry.

Sep 09, 2015 89 Replies

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Jim Thomas 10 years ago

That is connected differently, for just that reason.

So that even those as stupid as you are less likely to kill or significantly injure yourselves.

But not everyone understands that stuff.

But the current is what matters and you can be killed by a lot less current than it takes to blow the fuse.

I don't worry. I do however have enough of a clue to check if a car is coming before crossing the road and do things safely when that is just as easy as doing things dangerously.

In your case it was survival of the most stupid.

That was the reason for the change.

Must be why you whine about having to comply with the requirements to get benefits.

No point in one when completely unemployable.

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Jim Thomas 10 years ago

Then your head would implode and that would look bad on their records.

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Jim Thomas 10 years ago

Not when the cat triggers the PIR that has not been turned off.

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John Rumm 10 years ago

And let's say someone wanted to work on the switched live - adding an additional lamp perhaps?

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Tough Guy no. 1265 10 years ago

What part of "walk in front of both PIRs" didn't you understand?

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Jim Thomas 10 years ago

What part of "PIRs which has no indication that its been triggered" didn't you understand?

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Tough Guy no. 1265 10 years ago

The wires you're working on would become live, and your meter would indicate this.

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Jim Thomas 10 years ago

But you can't see the meter when you walk in front of both PIRs.

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Tough Guy no. 1265 10 years ago

What kind of s*it meter do you have? Doesn't it have a max/min function?

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Tough Guy no. 1265 10 years ago

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