Building a switch to invert current

I got a small electrical engine the other day, and I have to hook it up to two switches so that one switch starts the engine clockwise and the other counter-clockwise. My initial thought was to simply hook it up to two separate batteries each with a switch and one with the current reverted (like illustrated). But I'm wondering if there's a better way to go about this. For instance I have no idea if accidently activating both switches simultaneously will blow up the engine :s

Picture of Building a switch to invert current
sort by: active | newest | oldest
1-10 of 13Next »
Jaycub7 years ago
Don't worry, if you turn on both switches in this circut nothing bad would happen to the motor. It would just be shorting-out the batteries in series.
comodore7 years ago
What you need is an H-bridge, that's just the thing used in toy cars, so it can go forward and reverse.
Here is an Instructables on how to make it.

Hope it helps! :D
Flark (author)  comodore7 years ago
This does look like exactly what I need :) thank you for the suggestion (thanks to gmoon also).
comodore Flark7 years ago
ok, just trying to help. :D
more about transfer switch
what? :)
gmoon7 years ago
You might search on instructables (or elsewhere) for H bridge, there are several examples...
Flark (author) 7 years ago
Thank you for the suggestions. I do need the two switches to be separated though as they need to be pressed in two physically different locations, so I'm not sure if the DPDT-switch would work. I've found some schematics for DPDT switches, so will look into those to see if the logic can be transferred into something home-made. Again, thanks for the suggestions :)
you can do like this. youll need 1 dpdt (6 entries) (simple 2 state one without center off) and 1 simple switch (2 entries) each switch makes the motor work in 1 direction when both switches are on the motor just defaults to 1 direction if you want it to be off when both are on you need spdt (3 entries) instead of the simple switch
. You can use two DPST switches, but you will lose the "interlock" feature (you will be able to close both switches at once). . The wiring is much simpler than it appears at first glance. You just have to look at it for a while. The X that BinaryBoy mentions is what swaps polarity. . If you are familiar with house wiring, a three-way switch is a SPDT. Glue two 3-ways together (and bond the toggles together) to get a DPDT.
1-10 of 13Next »