GB plans for brushless motor controllers?

[glennmlewis]

Hi! I'm curious if GB ever plans to get into the controller business too, either by selling kits or by providing plans for the do-it-yourself -type person to make their own?

For example, it would be wonderful to have plans for something like the Hacker Master 77-3P Opto brushless motor controller (or another comparable controller (Jeti, etc.) that can handle up to around 70 amps and around 40 volts) on this site. I've seen some photos of similar controllers, and it appears as though some use an Atmel AVR processor to control it, which are fairly easy to program.

Thanks!
-- Glenn

[ScubaSteve]

Ummmm.......... :?

Gonna have to refer this one to KreAture :shock: :lol:

[budfly1]

YES YES Please

I would like to see a controler for the GB size motors! :P
It would be great to fly your own creation with your hand made motor AND ESC.

[ScubaSteve]

making your own ESC is MUCH more difficult than a GB kit, but we'll see :roll: ... :wink:

[Jay C]

If you want DIY, Speedy BL (http://www.torcman.de/peterslrk/SPEEDY-BL_eng.html) is the only kit I've seen. But it isn't cheap, and you need some test equipment to aid in troubleshooting. No way I could recommend Steve go that direction.

Jay

[Steve30]

Another thread on the subject:

http://www.rcgroups.com/forums/showthread.php?t=70373&highlight=diy+controller

Steve

[Catkicker]

this would be nice, being a flyer on a budget making my own gear is about the only way i can go bl. esc's are still the biggest cost.

[Happy|Harry]

i can't really see the problem here, CC PH10's can be had for under $45 nowadays :? sure the home built will cost less in materials building for the power levels we need for these motors(10/15A) but the time needed to build one surely outweighs the cost difference, and soldering smt components is very difficult to learn!

phil

[Catkicker]

yeah, but im nasa certified in electronics assembly, so i can do it. i would agree though, most would have problems if it were all surface mount stuff, but i'd hope they'd have a single chip system that could be used.

[Steve30]

The worst part about SMT components is dropping them on the floor :lol:

It depends what price you put on your time! I don't think I could be arsed! And I don't have a scope to fault find when it doesn't work :wink:

But if the design allows for addition FET upgrades and the price is cheap enough then it will appeal to some.

Steve

[Catkicker]

it wouldnt be worth making a kit with surface mount parts, too few people could work with them. heck, i'd have to give up pepsi for a week just to do it myself. and its been years since i did anything that detailed. they'd have to have a pretty simple system that used a single chip and just needed IO rigging for a kit to be viable.

[Steve30]

heck, i'd have to give up pepsi for a week just to do it myself.

I just keep my alcohol levels topped up :D No shakes here :lol:

Steve

[Happy|Harry]

if the design allows for addition FET upgrades and the price is cheap enough then it will appeal to some.

Steve

this got me thinking, the PH10 uses fairchild semi FDS6679 fets (check the spec's on the datasheet, VERY interesting! ;)) that cost about $0.90 each, if i had the patients i'd try doubling up the fets on one of my PH10's for an uberlight 20/30A esc :D

phil

[Steve30]

I couldn't find a datasheet, but I've seen FET's doubled up by soldering another over the top to double output capacity, the only concerns is are the components on the output up to the extra ampage!

Come on Phil break out the electronics catalogue.

Ste

[Steve30]

Phil,

Warning!****************************************** ***********
I've had a lot of beer / vodka and I'm watchin' the osbournes, but.......
************************************************** **********

If you need help with the soldering / electronics side of this thread I'm up for it, but doubling the output could seriously affect the esc (not sure without the circuit diag), but if not this could be the biggest thing since free SKY TV (joke, please do not contact me).

Ste

[Happy|Harry]

i'll check the rest of the components out tommorow as the print is much too small to see in artificial light, but for the fet's you can check the datasheet HERE (http://www.fairchildsemi.com/ds/FD/FDS6679.pdf), these fet's aren't that small (SO-8 ) so i'll manage those n/p but if the resistors and caps need changed too i'll need help as those are all about 2x1x0.5mm :o (sorry never worked with smt so i don't know the correct type No: ) i'll post back tomorrow ;)

phil

[Cyberman]

Well I'm sure you are well aware of this but making a brushless Electronic Speed Control is non trivial.

For example you need to make a 3 phase bridge output stage, this sounds simple enough, but it's not simple at all. Especially if you go over 20V because the gate drive voltages of the fets become a problem. Most solve this by using PMOS fets for the high side drivers. This is a partial solution however, you will have a LOT to consider.
Once you get the bridge design done and the proper layout to drive them (there are a bunch of parts you need just to keep the FETS from going ape with high frequency ringing).

Now you have to sense the back EMF, to guess the phase angle of the motor.

After all that you have your control algorythm to implement. Plenty of stuff on the net reguarding it, however it's still not simple. The controler choice for example is important. Size weight of components. Board layout for a 4 layer board, it's a high frequency circuit so you need ground and power planes to prevent nasty noise problems. Then you have to consider, low voltage cutout, current limiting and other features.

I'll get around to working on the one I started sometime, however still got work to do with other projects :D

Cyb