auto reverse polarity switch

Thread Starter


Joined Oct 10, 2011
Hi, I'm looking for a auto reverse polarity switch or circuit (small) to be used
with a on /off switch(mom on), replacing the original forward/reverse switch
(on-off-on). The original switch operates a battery powered screwdriver gun, 4 to 9 volts dc. It is a low RPM,high torque screwdriver gun.
The new switch or circuit needs a cycle time of 1 to 2 seconds in each direction (forward then reverse ) continuously when the on button/switch is pressed. Due to space,a mechanical solution isn't practical. I'm all thumbs in electronics. Any help is welcomed and greatly appreciated. thanks


Joined Nov 27, 2012
It would help to know how much current the motor draws especially when it works hard.

Are you able to measure that?


Joined Aug 23, 2012
Switch → NE555 Mono astable → NE555 Toggle Switch → Relay → reverse polarity

Search on google : NE555 Mono astable
Search on google : NE555 Toggle Switch