inexpensive BRUSHED DC motor controller??

MrDude_1

100 kW
Joined
Aug 17, 2012
Messages
1,016
Location
Charleston, SC
I am hoping someone here can help point me the right direction.

I recently acquired a kid-size electric kart. I plan to start a build thread soon. It has a massive "1hp"-24v-42amp continuous Ohio Motor on it. Manufacturer data allows 550+ peak amps. :shock:

I dont need that much amperage... but 300 peak, 100 continuous would be nice. Something similar to a 12fet Lyen controller... except its brushed, so while that lyen brushless controller has 4 FETs for each phase, I only have one phase... so if you shoved all 12 FETs into PWM for one phase, it would be perfect.

so my thought was.. there would be a 12fet brushed controller like lyens somewhere.

I cant find it.

I found the "YK43B controller". It has 12FETs and people rave about it with kids toys.. but there is no current limiting at all. No cutouts. nothing more than power in, power out, and throttle.
The other options seem to be golf cart controllers (HUGE in size) or small EV-car controllers (expensive, and large).

The YK43B controller was only $30.. so I have one on the way.. and it will be fine for myself to test... but I can not let kids ride it with it. No current limiting. no brake cutoff.. not programmable. a kid holds the brake and throttle.. it would melt something. kid hits the throttle, it will go too fast. no way to dial it back... and last, I plan on running used EV lithium, so I want some kind of current limiting.


So... where can I find a 24-100 volt DC controller that is 100a continuous, 300-ish amps peak, with programmable amp limits? Im flexible on the voltage... but if it cant go as low as 24, it would have to have a speed limiter too.
 
Look into Alltrax, Curtis, Sevcon, Navitas. Kelly looks good but actually suck. Used golf cart controllers are an option though most are 36 or 48 Volt.
 
Why do you want 100/300 amps on a kid kart ?
That yk43 probably wont push much more than 30amps at best, so you need not be concerned for the kids, and if you want to restrict it further you could always fit a throttle limiter.
Running 100+A at 24 volts will need a spendy controller and some serious wiring upgrades.
 
Parallel two cheap controllers.
 
MrDude_1 said:
so my thought was.. there would be a 12fet brushed controller like lyens somewhere.
The closest thing I have any experience with is
http://www.4qd.co.uk/product/4qd-range/
but it is also priced up there ...

It's not "programmable", as it's a fully analog controller (no MCU), but it has a number of things that can be adjusted via controls on the unit (potentiometers, IIRC).

They're not all that large, either. I had one on CrazyBike2 that ran the powerchair motor on there several years back, before I went hubmotor...and it did really well, given what it went thru. :)


Side note: The FET counts for brushed aren't the same as brushless, because brushed has only two bridges, not three, and they operate in a different way.

Most of the time only half the FETs are ever even used---only if you engage the reverse function does a four-quadrant brushed controller use the other FETs (and then it turns off the forward half).

There is some good tech info about how brushed stuff works on the 4QD site.
 
amberwolf said:
The closest thing I have any experience with is
http://www.4qd.co.uk/product/4qd-range/
but it is also priced up there ...

It's not "programmable", as it's a fully analog controller (no MCU), but it has a number of things that can be adjusted via controls on the unit (potentiometers, IIRC).

They're not all that large, either. I had one on CrazyBike2 that ran the powerchair motor on there several years back, before I went hubmotor...and it did really well, given what it went thru. :)
analog works too. Im in the US, so I dont know my pounds to USD, but I think 300 pounds is almost 400 dollars. seems expensive for an analog controller, but I have it bookmarked just in case I cant find anything cheaper.


amberwolf said:
Side note: The FET counts for brushed aren't the same as brushless, because brushed has only two bridges, not three, and they operate in a different way.
Most of the time only half the FETs are ever even used---only if you engage the reverse function does a four-quadrant brushed controller use the other FETs (and then it turns off the forward half).
There is some good tech info about how brushed stuff works on the 4QD site.

I only need forward, so really just PWM on one set of MOSFETs works for me. lol... but yeah, I know what you mean. Thanks for the website link. Have any more tech info sites on making your own controller circuits? Im very tempted to make my own here.. The newest large mosfets are amazing... they rival IGBTs in power ability, but switch super fast. (not that I need fast switching PWM in this case, but its good for current limiting with minimal spikes)
 
4QD do a much cheaper, non-reversing controller if you can live with 100A continuous: http://www.4qd.co.uk/product/porter/

Current exchange rate is 1.3 USD to 1 GBP
 
major said:
Look into Alltrax, Curtis, Sevcon, Navitas. Kelly looks good but actually suck. Used golf cart controllers are an option though most are 36 or 48 Volt.

yeah... the usual suspects. lol.
The problem I have with them is they cost more than the whole kart... I'm not trying to build a car. And Kelly... they're just downright misleading with their specs.
I already know the cheapie unregulated controller I have coming out performs their largest mini DC controller stuff.

Another reason I want a programmable controller is voltage range. I dont want it to over discharge, as kids will keep going until it cuts out... but I want to run as high as 66v.



Hillhater said:
Why do you want 100/300 amps on a kid kart ?
That yk43 probably wont push much more than 30amps at best, so you need not be concerned for the kids, and if you want to restrict it further you could always fit a throttle limiter.
Running 100+A at 24 volts will need a spendy controller and some serious wiring upgrades.

why? because I dont want it to suck.
This is a former rental track kart. Its the "kids" cart to them because of the frame size. I still fit in it at 6ft, but just barely. Its all steel, overbuilt with real race kart brakes, slicks, steering, etc. Unlike a true race kart thats built to be light, this is overbuilt to be beefy. I could put a motorcycle engine on it without reinforcing...lol
This isnt for just young kids, kids of all ages will drive it. This is whats going to convince the next generation that electric vehicles dont have to suck. Think teens that are motorsports fans... Think grown adults that fit. I even have the silly idea of running it at a few local SCCA autocross events.

How do I get 100/300 amps?
Right now, using 4 goped lead acid batteries. they're in a 2p2s config making 24v and capable of just over 100a.
I tested the cart with a contactor and switch. from a dead stop I pull that 100a and its just meh. It doesnt totally suck, but I also am no where near the traction limit or wow factor... its just that these batterys cant do more.
A kart like this should burnout if I floor it from a dead stop, and it has slicks so its going to take some power first. lol. Remember how everyone brags about the "instant torque" of electric motors.. but then most builds make less power than their gas equivalents. I want these kids to go "wow, my kart cant do that" not "oh, thats neat" or "my kart is faster". At the very least I want to launch out of the autocross start.
I plan on running Leaf or Volt cells, whatever comes up first locally. In either case, pulling 300a bursts will not be an issue.
This is at low voltage, so we're only talking 2400 watts at the moment (100a) and 7200 peak watts as a goal(300a). The non-kiddy karts are 8200watts already (11hp)
Another reason it has to be an amp limiting controller, is that I will eventually raise the voltage to increase top speed, and I want to keep peak wattage reasonable. I wont be pulling 300a at 66v, as thats almost 20kw. lol.

as to wiring upgrades.. I snagged plenty of wire from the other karts, so I have a couple hundred feed of very flexible fine stranded wire about 1" dia with the jacket, that was intended for commercial kart use on 11hp karts. wiring, contactors, and controls wont be an issue, I hit the jackpot!

I plan to make a build thread soon, I just havent had good weather yet. Im on the east coast and storms keep sitting just off shore, throwing rain every evening.

heres a pic for a better idea.. I already took off the "ring" bumper, stickers and hit it with the pressure washer a bit to clean the rubber off the plastics.
20160918_174938 (Medium).jpg
 
Another random thought... if the cheap "dumb" controller works, I can just run a Cycle Analyst V3 for current limiting, temp limiting, brake override, etc.
 
MrDude_1 said:
I found the "YK43B controller". It has 12FETs and people rave about it with kids toys.. but there is no current limiting at all. No cutouts. nothing more than power in, power out, and throttle.
Do you have a link about the YK43B innards? I've looked at the brushed offerings in the past and it seemed a used Alltrax or Curtis was the budget choice in programables.

Hillhater said:
That yk43 probably wont push much more than 30amps at best, so you need not be concerned for the kids
:lol:

Subject: Dequinox's HIV Build - new frame acquired!
dequinox said:
…I'm consistently drawing surges of 101-140 amps (36v) out of what is supposed to only be a 1000w controller!
Subject: 36v controller for a currie Ezip
flyinmonkie said:
I use the yk43b and it is a beast. I have seen peaks of 130amps and over 5000w with 12s of lipo, so 50v off the charger. I average about 2000w and maybe 40amps. I run it with a currie 1000w brushed motor. It doesn't limit amps, so make sure the rest of your system is up to it because you can see some big spikes.
Clay
 
gogo said:
MrDude_1 said:
I found the "YK43B controller". It has 12FETs and people rave about it with kids toys.. but there is no current limiting at all. No cutouts. nothing more than power in, power out, and throttle.
Do you have a link about the YK43B innards? I've looked at the brushed offerings in the past and it seemed a used Alltrax or Curtis was the budget choice in programables.

Yes, but only if you read Polish! lol Heres the google translated version.
https://translate.googleusercontent.com/translate_c?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&tl=en&u=http://forum.arbiter.pl/viewtopic.php%3Ft%3D1683%26postdays%3D0%26postorder%3Dasc%26start%3D0&usg=ALkJrhhybQZxKfZ2WC8bpj7yv1Pmgm8r-g


you cant see it in the translated one, so I'll attach the only two images I found online.
kontroler YK43 plytka.jpg
kontroler YK43.jpg

I had to laugh a little at the Hillhater comment too... He probably just looked at the spec printed on each one.
The KY43B appears to be a 12fet PWM one side controller with the other side straight in and out.. there is no current limiting of any kind. 80v caps too. the logic power supply is whats limited to a 60v max.

also in the link below, you will find a chinese claim of 820a peak.. I laughed a little at that too, but its only 68 amps per FET... so if the FET spec sheet says 70A.. LOL. (yeah right)

http://zjmy-lu.en.made-in-china.com/product/OXbJLZYxrCkh/China-Brush-Electric-Tricycle-Controller-24-60V-500-1000W-Yk43b.html


in anycase, it will put out whatever the motor asks of it, until something smokes.
 
Thanks for pics. The potting must of been a mess to remove.

I can't remember anyone using a C-A on a brushed motor. It senses the timing of the 3-phase for distance/speed, so that part wouldn't work. The rest measures battery amps, so it might work for motor limiting?
 
gogo said:
Thanks for pics. The potting must of been a mess to remove.

I can't remember anyone using a C-A on a brushed motor. It senses the timing of the 3-phase for distance/speed, so that part wouldn't work. The rest measures battery amps, so it might work for motor limiting?
The hall sensor option for speed is common, but they have an external speed sensor version for geared hub motors, and other devices. It works well for any DC circuit. It's a pretty awesome device.

Really it's all one version, just different wire connections.
 
gogo said:
I can't remember anyone using a C-A on a brushed motor. It senses the timing of the 3-phase for distance/speed, so that part wouldn't work. The rest measures battery amps, so it might work for motor limiting?
It'll work on pretty much any kind of DC-powered motor setup that uses a voltage controlled throttle or RC-PWM type throttle.

Speed sensor on a common BLDC motor only uses one of the 3 halls for the speed, and that only on a direct-drive hubmotor--every other version (almost) has to use a separate speedo sensor (usually a reed sensor on the frame detecting a magnet on the wheel spokes, just like any typical bike speedo/computer).
 
Just a follow-up to this controller... constant back to back 300a+ pulls never popped it and it was pulling enough to max out my 300a meter.
the wires eventually got hot enough to melt through, but I stopped and the controller still works. I now am looking for a new motor, as I sheared the shaft off on it.
for any toy needing a controller that will max the motor, I recommend this... as long as you dont need any safety features.
 
I've reverse engineered an older YK-42-3. The older version is very similar but used all through-hole parts. These things can really crank out some amps if the motor and batteries are up to it. Easily does 60A. LVC should be "programmable" with a resistor change. The newer ones apparently do not have any kind of current limiting. I once designed an add-on current limiter for them.

The YK-43 or clones are pretty inexpensive, so might be worth tinkering with.

Another one I have kicking around in the garage is an Alltrax. These were aftermarket Curtis replacements. 48v max, but big amps made for a golf cart. Search eBay for used ones.
 
No one has mentioned a VESC, yet. It is an open source controller that is capable of 240A for a few seconds or about 50A continuous depending on cooling. 8V-60V range. You can configure amp limits and safe voltage cutoffs.
 
Yeah, the VESC is cool, but its intended for brushless applications.
Since I am not limited in space, if I was running a brushless motor, I would just get a 24 mosfet ebike controller. same price, huge power.

The problem is that middle ground where I have a large DC brushed motor, but the common kiddy controllers are not large enough.
 
They do make RC controllers for brushed motors. Might work with some additional heat sink.
Random example: https://hobbyking.com/en_us/quicrun-wp-crawler-brushed-1.html $36. Says 80A rating.
 
fechter said:
They do make RC controllers for brushed motors. Might work with some additional heat sink.
Random example: https://hobbyking.com/en_us/quicrun-wp-crawler-brushed-1.html $36. Says 80A rating.

I have some experience with them and electric skateboards/scooters. Their problem is that they have no current sensing or limiting. So if you were to take the largest of these, 200a range 1/8 scale car ESC... it would still burn up with a motor this large, because it will try to sink all 300a.... and then the FETs pop.
I have been told some of the newest large brushless ones can be programmed into brush mode and do have current sensing, but im not sure what ones. I think they would have a similar fate as the YK43B... they would have issues with the peak amperage
 
I designed a current limiter circuit for the YK42 years ago. There are several possible variations on this, but this one used the battery cable as the shunt and just pulls down the throttle line when the limit is reached. It was built on a piece of perf board and stuffed inside the controller. It seemed to work OK. If I designed it today, I'd probably use a different op amp.

EZ Current Limiter 2.jpg
 
this is a really good idea.... :lol:
 
Another option: This place has some brushed controllers with current limiting:
http://electricscooterparts.com/speedcontrollers.html
 
fechter said:
I designed a current limiter circuit for the YK42 years ago. There are several possible variations on this, but this one used the battery cable as the shunt and just pulls down the throttle line when the limit is reached. It was built on a piece of perf board and stuffed inside the controller. It seemed to work OK. If I designed it today, I'd probably use a different op amp.

EZ Current Limiter 2.jpg

hey fechter! Not long after this post, I sheared the motor shaft on this kart. Had it sitting these last couple years. I decided to bring it back with a nice beefy motor, but was thinking about how someone posted a current limiting circuit... I searched and found this.

You mentioned you would use a different op amp today. What would you use?
Also, would you still pull the signal to ground or do you think running it in series with the signal so it hits a true ground is a better method?
 
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