MS20C PIR help required

[Arrowhead]

I assembled the MS20C PIR per the instructions on the page.
I hooked up the battery 9.6v panasonic and I let some smoke out :).

First I had one of the trace's smoke and I re soldered it, then I put the battery on it again and another trace smoked. Too large an area to re-solder.

Anything I might be doing wrong? Have you experienced anything like it? A guy I work with thought there was a short somewhere.

The instructions call for relay PN RS275-005, I could only find 275-005A which is a SPDT, your instructions say to use a SPST.

Do you think it might just have been a bad PIR board?

[Archilochus]

Hi Arrowhead,
Very not good to let magic smoke out of a circuit - makes it stop working ;)
>>>
To have enough current flowing to actually burn off a trace on the board means there MUST be a short somewhere. ###Re-check all the wiring (perticularly the polarity of the diode at the relay coil). ###Check that this diode is not failed shorted. ###Hopefully the sensor circuit has not been destroyed. ###The possibility of a bum sensor from the factory always exists, but even the cheapest factories test their products for gross failures such as this.

Good Luck,
Archilochus

[SWAMPFOOT]

arrowhead
that relay is fine i use it w/all of mine no problems. ###it is a 9v spdt relay it works great.

[wfontjr]

the 005a and 005 relay are the same, radio shack adds an "a" on the inventory, make sure the polarity is right on the battery, i once hooked a 12v battery backwards on the ms20 and fried the circuit, had to throw it away and start with a new one

[Arrowhead]

Thanks guys. I'll check it out tomorrow at work.

[Arrowhead]

Thanks for the help guys.

It was two bad diodes. I had bought another MS20PIR and wired it and it's ready to go.

Thanks for the help.