building speed controller out of solenoids?

i was thinking about building a cheap bang-bang speed controller today and came across this:

http://www.ukrobotics.com/html/hints&ti ... ontrol.htm

has anyone tried this or have any wiring diagrams?

You wire up the contacts of the solenoids in an h bridge and the coils of the 'diagonal' solenoids together and have a microswich to turn on each coil pair.

http://www.6x6world.com/forums/conte...ridge.jpg.html

Pretty similar to that but with two microswitches instead of a switch.

thanks :D

This may be ok :D

http://cgi.ebay.co.uk/WINCH-SOLENOID-24 ... dZViewItem

I'd recommend using solid state relays instead of solenoids.

http://www.jaycarelectronics.co.uk/prod ... BCATID=754

These would happily do the job. Mount it to a metal chassis for heat dissipation and these will keep running all day long. Stalled a small mag for 5 seconds or so with one of them. The mag was nackered but the relay was fine.

I'd suggest you weigh carefully the price of building a cheap bang-bang speed controller versus that of proper motor controller.

thanks for all the reply's :) i probably won't use bang-bang control. i was just thinking about using it temporarily until i can afford a proper one. but i'll just wait and hope someones able to sell me one used :D

Quote:

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Originally Posted by typhoon_driver

I'd recommend using solid state relays instead of solenoids.

http://www.jaycarelectronics.co.uk/prod ... BCATID=754

These would happily do the job. Mount it to a metal chassis for heat dissipation and these will keep running all day long. Stalled a small mag for 5 seconds or so with one of them. The mag was nackered but the relay was fine.

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These only close one way, so using them in an bang bang system would short the connection to the battery. Unless you put a hefty diode in front of every SSR. They are very good though, we've used them in our spinners as well.

SSR H Bridge
Take a R/C servo ... remove motor..... and replace with SSR H Bridge using the two spare wires on the left of pic.

This will/should give a crude fwd/rev speed control.
The negative MUST be common to both the R/C receiver /servo and the main battery... if your using a BEC it will be.
[attachment=0:2qo9qx0x]ssr h.JPG[/attachment:2qo9qx0x]

The contactor I suggested is a motor controller in itself with forward / stop / reverse all there with two units and 2 servos with micro-switches you have a simple bang bang controller for 2 motors. but I would still recommend a PWM controller.