# Motor PWM Controllers Too Good to be True [closed]

I am working on a project which involves driving 2 high power 60amp stall 12v motors from an arduino. I had been browsing available drivers, and everything on the market seems to be quite expensive (examples: this, this). However, I was browsing on Ebay and came across this generic board. It seems to have the correct specs to control one of my motors. Granted it doesn't have current sensing or anything else fancy like that, but does that really warrant an extra $150? If there is something wrong with that board, could you recommend me a cheaper alternative to either of the examples above? Thank you. ## closed as off-topic by PeterJ, Daniel Grillo, Nick Alexeev♦Nov 27 '15 at 22:06 This question appears to be off-topic. The users who voted to close gave this specific reason: If this question can be reworded to fit the rules in the help center, please edit the question. • Hah! I was just looking at a HHO controller on eBay as you posted this... – Ignacio Vazquez-Abrams Apr 25 '14 at 2:32 • @IgnacioVazquez-Abrams What is a HHO controller? – W5VO Apr 25 '14 at 3:52 • @W5VO: "HHO" is a colloquial name for oxyhydrogen, specifically when used as a dopant for petroleum in ICEs. A "HHO controller" presumably controls (via PWM) the current used for hydrolysis in HHO generation. (I wasn't specifically looking for HHO controllers, I happened upon one when looking for voltmeter modules.) – Ignacio Vazquez-Abrams Apr 25 '14 at 4:07 • You get what you pay for. – tcrosley Apr 25 '14 at 6:49 ## 3 Answers I'm not sure the one you found will be easy to interface with an Arduino as it is obviously controlled with a potentiometer. If you want to go on the cheap road, you should have a look at ESC for RC models. Brushed motor versions are rare as everyone uses brushless motors now, but you can still find a few of them. They are controlled with a ~30Hz PWM which is easy to produce with your Arduino, it's just like controlling a servo: http://playground.arduino.cc/Learning/SingleServoExample • Interesting. Out of curiosity, what would you consider to be the disadvantages to using either an esc or generic PWM vs a standard motor controller? – nanogru Apr 25 '14 at 4:14 • A standart motor controller like the one from Pololu will probably report error conditions (undervoltage, overcurrent, overheat etc...). An ESC for RC models will just stop in case of error. – martinm Apr 25 '14 at 9:02 They seem to have substantially different capabilities - and US design and manufacture increases cost. The Talon ($59) claims increased efficiency at stall - suggesting it may be energy converting to get stall current rather than just dropping excess V linearly - and is specifically robust and debris proof.

The Polulu ($200) includes a range of interfaces and mentions quadrature encodes, PID control and rather more. The$14 'HHO' is pot controlled, has vast quantities of heatsunk TO220's (or larger?) suggesting linear control, and probably doesn't know its PID from its quadrature. It's probably effectively an electrically variable electronic resistor bank - it MAY do speed feedback using motor back emf or may be wholly open loop. It MAY do what you need but may well fail valiantly.

Depending on your task (which you have not described so we do not know what you NEED) the \$14 may work. If there is a moderate chance the trying one and taking due care of your motor investment may be a good idea. May.

I am posting this answer as I have just realized the biggest disadvantage to cheap PWM controllers (and hobby ESCs): no reverse. That makes these controllers impractical for many applications (including my own) which require multidirecional control.