Space Heater Tilt Switch

[Excavatoree]

The space heater works just fine, but this switch rattles intermittently - it starts and stops at random.   I can't find anything like it on parts sites like Digi-key, and there's no information on the thing at all, other than the numbers 1-4 and a picture.

It rattles, but it's not just a ball and contacts, as there's no continuity between any of the four terminals, either tilted or not. 

Does anyone have any info about this crazy thing?  I wanted to simply replace it to see if that helped.     Diameter is ~17mm.   Terminals are in a .1 x .4 inch rectangle pattern.

The heater brand is Honeywell, but I don't think that means anything.  It's no doubt made in China with the US brand slapped on.

[andy3055]

You should be able to use a mercury tilt switch.

[fzabkar]

Maybe it's an active device, like this ...

https://www.romanblack.com/tilt/SFH7710_angle_sensor_using.pdf
https://www.romanblack.com/tilt/SFH7710_angle_sensor.pdf
https://www.romanblack.com/tilt.htm

Does it have Vcc, ground and output pins?

[Excavatoree]

Does it have Vcc, ground and output pins?

The question reminded me that I was being lazy and hadn't reversed engineered this as I should.  I was doing so, and noticed the power supply was a lot like the one in the larger heater Dave repaired in his recent video.  I also noticed a filter capacitor (220 µF, 35v) right next to the dropping resistor.  I thought, "might as well check it."  Turned out to be completely dry.  The capacitor checker didn't even recognize it.   (No capacitance, near infinite ESR)  It looked good.  No bulges, no leaks that I could see. 

So, as a first step, I changed it, and of course it isn't acting up (rattling) now.  I'll continue to operate it and see if the rattle returns.  It'll be embarrassing if that's all it is.

[james_s]

It may just be a metal ball bearing sitting in the middle of some contacts. As someone else suggested a mercury switch may work as a replacement.

Edit: I read your post again and see now that you said there isn't continuity. Maybe it needs more current to have continuity or maybe it's worn out and has gone high resistance? You could try temporarily bypassing it for testing.

[fzabkar]

So, as a first step, I changed it, and of course it isn't acting up (rattling) now.  I'll continue to operate it and see if the rattle returns.

Are you saying that the rattling was due to a bad supply? That would suggest that the device incorporates a normally open relay of some sort. :-?

[Excavatoree]

Are you saying that the rattling was due to a bad supply? That would suggest that the device incorporates a normally open relay of some sort. :-?

More like hoping rather than asserting.   I'll admit it doesn't make much sense.  It does have two relays, one for the fan, one for the element.  (similar to the heater Dave worked on.)

The thing works without the tilt switch in there, so I'm guessing it provides a signal to the microcontroller when the thing is tilted.   If my wife weren't using it at work, I'd just leave the damn thing out of it.  I can't come up with a logical explanation as to why it'll rattle for a bit, then go for minutes, hours, or even days without.  Plus the difficulty with getting it to rattle is making troubleshooting more difficult.

EDIT:  I've been thinking about it, and the switch is directly next to the relay.  How ridiculous is the idea that the unfiltered DC applied to the relay coil would make the ball in the switch rattle?   

[ledtester]

It rattles, but it's not just a ball and contacts, as there's no continuity between any of the four terminals, either tilted or not. 

Here are some 4-pin tilt switch offerings from alibaba:

https://www.alibaba.com/product-detail/RBS380100-electronic-tilt-switch-DIP-installation_62021775261.html

https://www.alibaba.com/product-detail/RBS040110-rolling-ball-tilt-sensor-switch_60529879325.html

https://www.alibaba.com/product-detail/Switch-Heater-Tilt-BL-1250-Series_62119555960.html

https://www.alibaba.com/product-detail/A2TS-H-Horizontal-installation-small-photoelectric_1600115805305.html

In particular, the first one is described as a "photoelectric switch" and mentions this patent:

https://patents.google.com/patent/US9863802B2/en

and the markings on the case clearly indicate which pins are used for the LED and the phototransistor.

So perhaps yours is also like this one.

[fzabkar]

This looks like the one:

https://www.alibaba.com/product-detail/Wide-Range-Useful-12v-non-mercury_1600154862237.html



https://img1.exportersindia.com/product_images/bc-full/dir_146/4369871/tbl_spec_92279_p_2897532.pdf

[Excavatoree]

That is indeed it.  I can' thank you enough.

 I was wondering why I couldn't find a direct ground connection as I tried to trace out the circuit.    It's used just as the data sheet suggests.

It's so cheap I went ahead and ordered some - might as well try exchanging it if the rattle continues.