DIY speed control with reverse

[bigandy]

Good morning all.

Can anybody recommend, or does anyone know of a diy electronic speed control for brushed 540 class motors that has a reverese function? I'm looking to build a controller to use on a RC boat project. To start with I'll be using some standard 540 motors, but if all goes well I will be putting in a modified 14turn car motor.

So I could do with a speed controller that can handle a fair amount of current, both forward and reverse.

I've done a fair bit of searching on the internet, but I seem to be able to find is fairly low amp designs without a reverse (meant for airplanes I guess). Is it possible to uprate these existing designs by adding more power transistor/FET stages in parallel with existing ones, until a suitable current handling capability is reached?

Thanks for any help/advice.

Andy

[clipclop]

Andy,
Read this thread http://www.rcgroups.com/forums/showthread.php?t=259623
This speed controller can be programed to do what you want , and yes you just need to use enough good fets to handle the current you want .
Stewart

[Bruce Abbott]

A bi-directional ESC must have either a relay or an H-Bridge to change polarity of the motor leads. A relay can easily be added to a forward-only ESC, but is bulky and may be unreliable. Most commercial reversing ESC's use the H-Bridge configuration.

Here's a website with circuits for several ESC's that use relays, and one H-Bridge:- Barry's Model Control (http://www.kleefeld.freeserve.co.uk/model/barry/pic01/rc_speed.htm).

Here's a complete Russian design for an H-Bridge controller:- http://www.rcdesign.ru/rus/electronics/esc_rev/esc_rev.zip, and a French one:- http://perso.wanadoo.fr/claude.dreschel/variateur_pwm/.

With the specified FETs they can only switch about 12A unless you use a large heatsink. Current could be boosted by using better FETs, or simply wiring more FETs in parallel. If you don't need full power in reverse you might get away with using lower spec MOSFETs in the reverse half of the bridge.

[odalaman]

Hi bigandy,

Try this thread; http://fmxstart.tripod.com/projects/mc_pic16/rc_speedcontroller.html

I have built two of these a year ago for my RC car and my hovercraft and they are still working good.

Enjoy

[soren]

Hi.

There was a fine (simple) analog construction in the Swedish magazine: "Altt om hobby" issue 7 - 1995. I have build more than 25 pcs. of these all working perfect.
Look my homepage: at: http://users.cybercity.dk/~ccc16084/ follow the "electronic page" link

You can find the Swedish magazine "altt om Hobby" at: http://www.hobby.se/

Good luck

Soren

[Buckey29]

If anyone builds these and wants to sell a couple, email me.
buckey29@yahoo.com. I need it to handle 8-10 amps max.

[lazy-b]

Here is my home made esc with reverse build on April 3,1989, its 15 years old, just use readily available components, I use IRFZ40 or you may use IRF530, I guess there a newer FET that can give even lower On resistance.

the 1st schematics diagram with 2 transistor direct drive, but have up dated it using opto-coupler, I use this on my Dual motor Clodbuster, work perfectly....for small load, u can use less FET, or can use more FET on Forward, and use less on reverse.

[marker]

http://www.oatleyelectronics.com/kits/k161B.html