type of diode/protection

[david watters]

im trying to figure out what type of diode or type of protection to use for my setup. im switching my sons baby swing over to dc power with a wall wart and a buck converter and that works great so far but my wife also wants to keep the ability to use the batteries. what can i use on the battery pack to keep it safe in case she forgets to unplug the adapter lol.

edit: its all running on 6 volts

 

[davenn]

im trying to figure out what type of diode or type of protection to use for my setup. im switching my sons baby swing over to dc power with a wall wart and a buck converter and that works great so far but my wife also wants to keep the ability to use the batteries. what can i use on the battery pack to keep it safe in case she forgets to unplug the adapter lol.

edit: its all running on 6 volts

Hi David
welcome to EP

6V and what current ?

 

[david watters]

thank you i cant believe i havent found this forum before

4 d cells worth lol one second and ill get a measurement
the meter set at 10amp i get spikes up to .6 but sits at .02 once up to speed

 

[hevans1944]

Perhaps you could wire in a simple DPDT toggle switch with a center-off position (ON-OFF-ON). Common terminals wired to swing motor, contact terminals wired to battery pack on one side and to wall wart supply on the other side.

 

[david watters]

ya thats my plan if i cant figure out some other way to auto switch it lol

 

[AnalogKid]

A SPDT relay with a 6 Vdc coil. Power the coil off whichever source you want to power things when both sources are connected (we'll call it the primary). When the primary source is removed, the relay will drop out and whatever is connected to the NC contact will run things until the primary comes back.

NC - secondary power source
NO - primary power source
Common - output to device.

ak

 

[hevans1944]

I suppose a rectifier diode (1N400x family) inserted in series with each supply, with the anode of each diode on the positive terminal and the cathodes tied together and connected to the swing motor would also work... at the expense of one diode forward drop (about 0.7 volts) decreasing the voltage to the motor.
That's why I suggested the mechanical switch: no losses. But if you want automagical switching try the diodes.