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I'm looking for a mechanical on/off rocker or toggle switch that can be reset to a default state and position upon the removal of power.

The application is in a vehicle where I want the switch to return to a default position once the ignition is turned off.

I know how to make such a switch using some digital logic and a momentary action, but the application requires better tactile feedback (and the ability to operate the switch without looking at it).

Does such a mechanical switch exist?

I found: Resettable latching switches and http://en.wikipedia.org/wiki/Relay#Latching_relay, which are close, but do not physically put the switch back in the original position.

EDIT: To clarify, the switch is to control a GPS tracker. I want the tracker to be "on" whenever the vehicle is powered up, but the operator needs the option to toggle the GPS unit on/off while they're moving around. I don't want someone to accidentally leave the switch in the "off" position and have the next operator forget to activate it. It's vehicle-voltage (24V in this case), low current (10's of mA).

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  • \$\begingroup\$ Knowing what your switch controls is important. No, this switch does not exist but there may be some alternatives you can use. \$\endgroup\$ – HL-SDK Nov 25 '13 at 18:24
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    \$\begingroup\$ digikey.com/product-detail/en/A8GS-S1305/SW1533-ND/4248837 maybe try one of theses and have a cap charged to 5V, a depletion-mode fet that is held off when your power is on and dumps the 5V charge through the coil when power is off? \$\endgroup\$ – scld Nov 25 '13 at 19:02
  • \$\begingroup\$ Chris, this is the coolest switch I have ever seen. I have project ideas already... \$\endgroup\$ – HL-SDK Nov 25 '13 at 19:24
  • \$\begingroup\$ Chris, that's exactly what I was thinking of, but failed to find on my own. Thank you! A Normally Closed function would work best for me, but I can work with that switch. \$\endgroup\$ – danpat Nov 25 '13 at 20:00
  • \$\begingroup\$ They're great. I know that more types exist and the one that I use daily is on a Kepco high power supply. I know the main "breaker" switch is externally reset. edit: I'll put this as an answer for future people to see. \$\endgroup\$ – scld Nov 25 '13 at 20:14
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http://digikey.com/product-detail/en/A8GS-S1305/SW1533-ND/4248837

Maybe try one of these. You could have a cap charged to 5V, a depletion-mode fet that is held off when your power is on and dumps the 5V charge through the coil when power is off? This would allow the switch to manually be reset even if power was lost and not purposefully reset.

edit: If it just needs to pop "ON" when the car turns on, have "ON" be the reset position. When the car turns on, have a circuit that momentarily 'resets' the switch to the "ON" position and then the switch will be toggleable.

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