Will this work as expected?


Joined Jul 9, 2011
Nope, no luck....

It doesn't really matter though. If the schematic on post #9 works that is... does it ?

No I don't think it does under load. When the switch is off, I think the upper PNP could turn on too, obviously not good.

Since your input is not a switch and your output doesn't require a Push-Pull why don't you tell us what I asked in one of my previous posts?

Is the input a high or low side or push-pull switch and do you want to sink or source current at the outputs?

Thread Starter


Joined Jul 17, 2011

thank you for answering!

This +/- or -/+ will be fed to this arrangement of switches and diodes that's built in a commercial linear actuator (these are mechanical components that I prefer not to modify).


The and result - at current DC motor's poles - will be three states:
open circuit/forward/reverse
which I plan to feed to the servo driver circuit instead.

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Joined Feb 19, 2009
Let me see if I understand this.

You currently have a BLDC motor and BLDC Controller.

You want to swap the Motor out for a brushed motor.

You now need control for the brushed motor in the form of reverse/off/on.

Is this correct so far?

Do you know how R/C servos work?

Please post a complete schematic of your solution, including diagrams so I understand what I think you are trying to do.

The servo signal is a pulse train, and an H-Bridge will NOT be able to interpret it at all.

A brushed motor ESC is $20, probably less than you'll end up spending on this project, which will most likely have issues even if you do get it to function correctly.

Thread Starter


Joined Jul 17, 2011

I currently have a linear actuator with a brushed motor that I want to replace it with a more powerful brushless one.

The Electronic Speed Controller will be an off-the-shelf R/C component - one that costs 20 bucks or less - so it needs a R/C servo input signal.

This servo pulse will be provided by a servo driver circuit. Yes I do know how R/C servos work.

I'll draw a block diagram of what I am trying to accomplish. Thanks for all the help!

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