Community Question

I am very new to EZ Robot. I have an EZ Robot kit. I'd like to hack an old toy a Fisher price ride on car that is powered by a single motor. I think 6 v. Would I need an Hbridge for this? If so which one? Or is there another way to connect and control this motor?
I'm considering taking the handle bars off and glue/screw a servo to the steering mount so I could control the steering with Ez-B. I think this toy could be a great chassis for building a larger robotic form factor.
I can provide a photo if needed.
Any thoughts or assistance would be greatly appreciated.
Thanks,
Keri
kd208
Commented September 2017
Will this work?
driver: L298N; driver power supply: + 5 V to + 35 V; driver output current (max.): 2A; logic power output Vss: +5 V to +7 V (internal supply +5 V); logic current: 0-36 mA; controlling level: low -0.3 V to 1.5 V, high: 2.3 V-Vss; enable signal level: low -0.3 V to 1.5 V, high: 2.3 V-Vss; max. current: 25 W
Found this t our local microcenter.
Thanks
thetechguru
Commented September 2017
That is very similar to the EZ-B one (2amps instead of 2.5, but same controller so will work the same).

Again, the key is how many amps the motor draws. If it draws more than 2 amps, you will see magic blue smoke.

Alan
kd208
Commented September 2017
After researching this am afternoon, it looks like the toy car outputs 4 amp hours or 4 now. So if that us true then I would need something like this I think.
http://www.jameco.com/z/RS011MC-Dagu-HiTech-Electronic-Motor-Controller-4-Channel-4-5A-4-5-12V-for-Rover-5-Chassis-Supports-Encoder-Mixing-_2150539.html?CID=GOOG&gclid=Cj0KCQjwr53OBRCDARIsAL0vKrNJij-mw2owUFBlMO-TtCxl5UIUTI4NrfwACQw-rrOzhIaOBwPenCsaArdqEALw_wcB

Does this sound correct?
Thanks and sorry for all the silly questions.
thetechguru
Commented September 2017
That is a 4 amp H-Bridge, but you say the toy outputs 4 amp hours. That sounds like the battery rating, not what the motor draws. A 4 amp hour battery can put out a lot more than 4 amps. 4 amp hours means that it will last for 1 hour while having 4 amps drawn from it. It would last 1/2 hour having 8 amps drawn from it, less the more power you draw. You really need to know what the motors draw to make the correct decision.

I just realized you said this was a rideable toy. Is it a Fisher Price Powerwheels? I think those motors are closer to 20 amps. (I know the fuse is either 20 or 25 amps)

That also may change the suggestion that you could steer it with an HD servo. It should be OK just driving the thing on its own, but if you put a child on board, I am not sure if the servos could handle turning it under full weight. They are strong, but there are certainly limits.

Alan
JustinRatliff
Commented September 2017
(What Alan last said.) Right, guys, remember he is talking about the Powerwheels cars for children to drive and ride inside! Not a toy RC car.

Josh did a Power Wheels conversion here

And so did Robotz
Question
Avatarby kd208
Published Sunday, September 24, 2017