I am building a series of handbuilt toys that need to be "ON" when positioned down and "OFF" when 180-degrees reversed or up. The devices are completely self-contained so using a positioning sensor is not an option. I can build a functional switch with a ball bearing housed in a closed tube with 2 contacts on 1 end and nothing on the other or use a mercury switch. As it is a toy, I don't want to do that. So, what is the substitute for a mercury switch?
TYIA, Thomas
"mechanized_robot" wrote in news: snipped-for-privacy@j44g2000cwa.googlegroups.com:
Tiny weight on the end of a lever on a microswitch?
I would google for (replace mercury switch) but what do I know?
"Homer J Simpson" wrote in news:uw08h.17992$C94.13625@edtnps82:
Try "mercury switch or" in Google. There, you know a bit more now. >:)
There are tilt switches made with a liquid metal which is not mercury and is supposed to be less toxic (something like a gallium eutectic alloy with some other metals).
There are tilt switches made with a ball and mechanical contacts.
There are tilt switches made with a ball and an optical sensor.
There are tilt sensors made with a liquid and differential capacitive sensing.
You can use an accelerometer if it has response down to DC (eg. the MEMS type).
There are, no doubt, others that I've not mentioned.
Only the 2nd one above is likely to work well for you. The ball and optical sensor is nice, but the current draw for the LED would quickly drain the batteries on a battery powered toy.
Google on "tilt switch". There are commercial switches made as described, but they may not be very easy to find in tiny quantities. Eg.
Best regards, Spehro Pefhany
ISTR a chain and contacts also.
First thing I checked; then I posted here.
That is a good idea, thanks!
"Tilt Switch", thank you!
How about a moving magnet and reed switch?
If its any help, scrap CD/DVD drives contain several tiny low force switches that could be ideal for your application !
Regards,
Boris Mohar
Got Knock? - see: Viatrack Printed Circuit Designs (among other things)
void _-void-_ in the obvious place
Some soft toys have a soft switch in a hand or somewhere that turns it on and it times of after a little while. Might be better than relying on turning the toy over.
John G.
Assemtech do a range of tilt/vibration switches. Many consist of a gold-plated ball bearing in various contact configurations
The generic term is "tilt switch" or "tumble switch", try searching the catalogs for that.
Even more generic and without moving parts, are accelerometers. Some make analog outputs, others digital for interfacing to a microcontroller.
Tim.
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