I have to find a radio channel controlled momentary switch that simply bridges a contact (No load applied). It is to take the place of a physical SPST momentary switch in a lighting control system.

I tried to use the Turnigy type switches, but they won't work when just trying to complete a circuit.

Use the Turnigy switch to drive a relay ?

you could always use a micro servo to push the switch

Yeah, that's what i have now- high incidence of failure when making mechanical contact. The points fail because of vibration.
I'm trying to avoid a relay, but thanks for both suggestions.

Could you make your system work by receiving a 5v signal, or do the contacts actually have to be bridged? If you just need a 5v signal you could use an ATTiny micro-controller. I have one setup to translate a servo signal into an on/off signal for a lighting system, but you could easily program one to act like a momentary switch. If you want something pre-built look at this:
http://store.3drobotics.com/products...switch-v10-kit
It is the same idea, it would just need programming.

Originally Posted by m056678

Could you make your system work by receiving a 5v signal, or do the contacts actually have to be bridged? If you just need a 5v signal you could use an ATTiny micro-controller. I have one setup to translate a servo signal into an on/off signal for a lighting system, but you could easily program one to act like a momentary switch. If you want something pre-built look at this:
http://store.3drobotics.com/products...switch-v10-kit
It is the same idea, it would just need programming.

That might do it. I'll have to read more tonight after work! Thanks

You know, i wonder if there is a remote shutter switch out there that might do it?
Aren't some of them just an electronic momentary switch that bridges a contact?
Anyone know of one?

You mean like an analog switch.... Something like the ADG333 ( or MAX333 ) does just that, although it's a quad SPDT in a 20-pin DIP package. If to wires need to be shorted, however, and there is no need for it to remain floating. You can simply tie one down to GND, and switch the other to ground with an N-channel MOSFET -- small package, reliable and low power. Otherwise, something like the analog switches above might be necessary to retain some small isolation.

Martin Jay McKee

Originally Posted by Jarold C

Yeah, that's what i have now- high incidence of failure when making mechanical contact. The points fail because of vibration.
I'm trying to avoid a relay.

Useful information to have included in your original post then.

Why are the points in a lighting system (whatever that means ?) being subject to vibration ?

The points in the mechanical micro-type switch go bad quickly from any type of vibration. They don't last in a plane, car, heli, or motorcycle. They are happy only in a stationary project (model trains). Even then they go bad after a couple hundred cycles.

Originally Posted by mckeemj

You mean like an analog switch.... Something like the ADG333 ( or MAX333 ) does just that, although it's a quad SPDT in a 20-pin DIP package. If to wires need to be shorted, however, and there is no need for it to remain floating. You can simply tie one down to GND, and switch the other to ground with an N-channel MOSFET -- small package, reliable and low power. Otherwise, something like the analog switches above might be necessary to retain some small isolation.

Martin Jay McKee

That's what I'm looking for! Should work! Thanks!

Somebody in an electronics forum said i could just use a J-fet, but that was the limit of his answer. Makes sense, but my electronics education is sadly lacking and dates back to tubes. I did find an spst analog switch that i think will work- thanks all!

Originally Posted by mckeemj

You mean like an analog switch.... Something like the ADG333 ( or MAX333 ) does just that, although it's a quad SPDT in a 20-pin DIP package. If to wires need to be shorted, however, and there is no need for it to remain floating. You can simply tie one down to GND, and switch the other to ground with an N-channel MOSFET -- small package, reliable and low power. Otherwise, something like the analog switches above might be necessary to retain some small isolation.

Martin Jay McKee

If I understand the datasheet for the MAX333, you would still need something to convert the PPM signal coming from the receiver to a logic high or low signal to feed in to the MAX333 (like an Atmel micro-controller).

Yep, a modified turnigy remote switch

Originally Posted by Jarold C

Somebody in an electronics forum said i could just use a J-fet

Quite likely, or standard junction transistor.

Whereas an analogue switch might not work.