Asked — Edited
Resolved Resolved by Rich!

Doc Motors/H-Bridge

Hello everyone.

Am sort of a noob to robotics but I want to get my old RAD robot back to life, and for the two motors I know that it needs an H-BRidge. I saw the manual on how to connect it and all that fun stuff but one of my questions is, If I were to use an H-BRidge on different motors how would I know if the motors would run properly? I guess what I really mean how do I know what types of motors to use and what motors not to use?

Also the H-BRige does say 2.5 amps but is that how much amps it can hold?

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OK, first off, a H-Bridge doesn't hold any current. The 2.5A is how much current it can handle or in other words, how much current the motors can draw from it.

With that in mind, you would require motors which are rated no higher than 2.5A maximum current draw, often marked up as peek current or stall current.

The datasheet for the L298n states the absolute maximum currents are as follows; Peak Output Current (each Channel) 3.0A - Non Repetitive (t = 100µs) 2.5A - Repetitive (80% on -20% off; ton = 10ms) 2.0A - DC Operation

So, what motors can you use? Any which fit and are under 2.5A peek. Avoid anything above that as the H-Bridge will not be able to cope with the current draw for longer than 100µs.

As far as voltage goes, according to the datasheet the L298n absolute maximum voltage for Vs is 50v.

Having a RAD myself I was very pleased (and surprised) by the stock motors in it. Sure, they are noisy however that's more the gearbox than the motors. Personally I didn't change them and saw no reason to.


Awesome info Rich! I would also recommend keeping the motors that the RAD comes with.


Thank you so much for your response and time Rich, I think I understand this a bit more :)


Thank you for the recommendation DJ I'll keep those motors