Alternative to diodes that limit control of one device between 2 circuits?

eagletalontim

To explain a little better, I have to controllers that control one motor (positive control) depending on which one the user wants to use at the current time. When one circuit is powered up, the other's power is removed and visa versa. The grounds are always connected as I cannot change the factory circuitry which is naturally grounded. Right now, I am using 2 diodes in "parallel" and due to the size of the diodes, it is quite bulky and it costs me more time and money to solder 3 wires to each "diode pack" then put heat shrink on everything to seal up the connections. Is there a better device that will do the same thing?

Factory Circuit ------------------->|-------------|
                                                  |--------------------------Motor being controlled
My Circuit ------------------------>|-------------|

The reason for the blocking diodes is to prevent either circuit from being supplied power when the user has selected the other circuit to be in use. The factory circuit cannot handle this. I am looking for a single package that does not require being switched on or off and can handle 2 amps without heating up. Any ideas?

Phil Pilgrim (PhiPi)

Which diodes are you using now, and what's the maximum voltage?

-Phil

eagletalontim

This is the one. Bought a bunch awhile back and decided to try and use them for this project. The max voltage would be 16V and the max amperage would be 2A. The "forward voltage" must be as low as possible.

http://www.digikey.com/product-detail/en/6A10-TP/6A10-TPMSCT-ND/773698

Tubular

You want a Schottky diode that will significantly reduce the forward voltage drop. I imagine Phil's on the case if not I'll look one up later.

Sapphire

You could use one of these, on a small PCB with a 3-position screw terminal.

Tubular

Yeah thats the kind of thing

I found this one
http://www.vishay.com/docs/94252/94252.pdf

Forward voltage about 0.5v at 2A, but drops as it warms up. You can easily screw or clip a heatsink on if you like.

jmg

eagletalontim wrote: »

The "forward voltage" must be as low as possible.

If a diode drop is too large, google Ideal Diode or Mosfet OR'ing Controller, and you can find ICs designed to do this using MOSFETS to get very low drops.