Please help identifying a device.

[calli]

I found this device on the street, several cars did go over it.

I checked resistance just something about 0.6Ohm, does not change with temperature as it seems.

Diode test shows both poles are equivalent.

Block is steel or nickel maybe, a magnet attaches to it. No reed contact.

Plug is 2.3mm. Two poles.

Wild guess: Some sort of antenna? Some inductive thing? But cable is not shielded...

Your guess?

Thanks,
Carsten

[isometrik]

It might be a temperature sensor.

I onced used a 10K? thermistor based temperature sensor that had a very similar case form factor. See https://www.digikey.com/products/en?keywords=615-1082-ND

Since your device has such a low resistance, could it be a thermocouple ?    Try measuring the open circuit voltage while having the metal case at different temperatures.

[chris_leyson]

Might be an induction loop pickup or maybe a proximity detector.

[Twoflower]

Could be a reed contact for window/door open alarms. And yes there are NC reeds out there.

I should read the full text first...

[calli]

0V  No Termocouple.

And I guess for all frequency/induction stuff one would use either symmetrically lines or at least shielding.

Reed switch i guessed first, could be always close when broken, but I guess a reed would not be in a ferromagnetic case.

Last resort would be to crack it open.

Carsten

[edpalmer42]

Bimetallic temperature switch?  It's closed now, but if it gets too hot (or maybe too cold) it snaps open.

Ed

[SeanB]

rersistance is suspicious, check it is not just a diode in there, as it will be around 0.6V one way and open circuit the other. Likely a diode temperature sensor, meant to be plugged into some controller or the other for use in air temperature measurement.

[Gyro]

Curious that something like that would have a consumer grade 2.3mm jack on the end, not what I would expect for an overtemperature switch. Maybe some sort of accelerometer or vibrating device/sounder?

Just a though (but these days...), hopefully it's not something that does something nasty or dramatic if you put power through it! 

[bktemp]

Maybe a reed switch for a cheap window alarm sensor? Many of them are normally closed.
The cable doesn't look heat resistant, so I doubt it is a overtemperature sensor. Consumer grade temperature sensors are typically NTCs in 1k-100k range.

[Twoflower]

One other try from my side: A position sensor (e.g. mercury switch)?

[calli]

Bimetallic: Heated it with a torch up to about 70°C nothing.

The resistance changes from 0.6Ohm to 0.8Ohm or such then....

Diode Test does not show any diode type characteristcs.

Orientation or accel does not change any resitance/continuity

Next:

- Check on Oszi component tester
- check (how) for being a active component
- send it dave as mailbag :-)
- your idea?

I am still hoping someone will recon this piece :-) Curiosity kills me...

Carsten

[calli]

Component tester shows a vertically line.

Carsten

[calli]

Broke it open. Take "broke" literally. That was quite hard gunk (sp?!) inside.

What I found and broke was something looking like a reed contact. Really.... In a magnetic hull?! Still confused about this device. 
 
Still could have been (grammar?  ) a bimetallic thingy. But Google does not find anything looking like a reed but beeing bimetallic.

Carsten

[JolyGoodDay]

Looks like.

Magnetic sensor, paired with a magnetic for a door/window/ect to detect closed/open state for a alarm system. Maybe missing its plastic housing that has screw mounts.

Never seen a 3.5 connector on one before tho... I would consider it a bad idea.

I can see it coming from a blister pack product at Walmart, labeled as "Easy Home Security" powered by 2 AA batteries with a piezo alarm.

Then again what do I know.

[fcb]

Might be the sensor from one of those 'hotel door alarms' you used to be able to buy. How long is the cable?