Crystalyte 35a controllers

The amp rating.. and the voltage rating are not the same thing.

a 36v controller can be run at 48v.. but not 60 +..



You need a controller rated at 72v to run 72v.


the 35/40 amp rating is how much current the controller will alow the motor to consume on full throttle or heavy load...

A 36v controller.. run at 48v will be ok.. but will not cut-out when your battry pack hits rock-bottom... 36/48v controllers are the exact same thing except the LVC = Low Voltage Cut-Off.

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A 36/72v controller can be run at up to 99v.. but same thing.. will not cut out until the voltage hits 29v.. wich will not happen with a 72v pack. (Unless you run it to the ground.. )

http://www.poweridestore.com/Brushless-Controllers/Series-500-Controllers/35A36V-72V-X-5-Motor-Controller

8)

I'm not sure if I trust the pictures to be right, but the standard "black
box" Crystallyte contollers have FETs and caps rated for 100v, which means you can run 72v no problem.

As Ypedal points out, the real difference in the voltage ratings is the low voltage cutout. This can be easily modified to be whatever you want it to be.

If the 35/40 amp controllers use two of the same FETs in parallel as used in the 20 amp controllers, are the 35 and 40 amp controllers exactly the same except for the shunt value?

That's what I would guess. We would need to read the numbers off the FETs on a 40 amp model to be sure.
The 35 amp one uses IRFB4710's

Before I bought the 72v 35amp controller from the poweridestore, I wrote electricrider for info about their 48v40a crystalyte controller. The owner replied that the 48 volts meant 48 volts, and would not handle 60+ volts. He told me there was no reason to go for a higher voltage anyway, as 48 volts and 40 amps was plenty. :?

72 Volt will give you a more range in miles. ie: Amps = torque and volts = mileage.

How to determine the optimal amp limit for an ebike:

1. Figure out what's gonna blow up your components.
2. Back off a little.

Mathurin said:

How to determine the optimal amp limit for an ebike:

1. Figure out what's gonna blow up your components.
2. Back off a little.

Click to expand...

Well I can say for sure that my 72/35 controller did not like 45 amps. Even if I only wanted to run 35 amps, I'd feel a lot better with upgraded FETs that don't run anywhere near meltdown.

the "brick" sized black controllers sold by crystalyte and powerpack motors are all basically the same except for the voltage rating. the 48v will work up to 55v and the 72v unit will work up to 100v. the difference is the voltage rating of the fets and the big electrolytic caps on the main power bus.

the fets in the 72v controller have higher on resistance than the ones in the 48v unit, so it wastes a few more watts as heat. as was mentioned, the biggest difference is the low voltage cutoff, which is controlled by a string of resistors near the edge of the pcb below the pwm chip.

the 35a and 40a controllers are identical except that in the 40a an extra conductor has been added to provide the higher current limit.

the design of the 35/40a controller is very similar to the 20a unit with the exception of the fet drive circuitry and having twice as many fets in the 35/40a. they just use two fets in parallel for the low side switch, but on the high side, where the PWM switching takes place, the extra gate charge of the two fets is too much for the ir2101 driver, so they add a transistor drive stage to the high side fets.

i have posted before about how i am using the irfb4310 in these controllers as a general 100v replacement. they seem to be performing reliably and putting 8 of them in a 20a controller and modifying the shunt seems to make it a reliable 35a unit. i have not checked these in very hot weather, so it will be important to watch it when it gets hot and see if more heat sink is called for. the lower Rds-on would lead me to believe it will not be needed.

-bob

So there are no other differences between a 35 and 40 amp controller, besides the current limit itself? I guess that makes sense if a 40 amp controller is essentially 2 x 20 amps in parallel.

Mathurin said:

How to determine the optimal amp limit for an ebike:

1. Figure out what's gonna blow up your components.
2. Back off a little.

Click to expand...

That's exactly how Colin Chapman performed the engineering work on his Lotus F1 cars. The results speak for themselves as Lotus held the record for the most F1 wins up until a few years ago when Ferrari with Schumacher surpassed them, & Lotus had been out of racing for over a decade!

While it's nothing official, I think Lotus also killed more of it's pilots than any other builder with this kind of engineering.

bobmcree said:

the "brick" sized black controllers sold by crystalyte and powerpack motors are all basically the same except for the voltage rating. the 48v will work up to 55v and the 72v unit will work up to 100v. the difference is the voltage rating of the fets and the big electrolytic caps on the main power bus.

Click to expand...

I'm not sure about that. The ones I have were 24v / 36v and all the parts are rated for 100v. The only difference is the low voltage cutout setting.
I'd be interested if they made them with anything other than a IRFB4710.

the 48v will work up to 55v

Click to expand...

This is what I was told by electricrider. In reply to my query, the owner wrote me that none of their controllers handle 72+volts:
http://www.electricrider.com/parts/controllers.htm
He stated he sees no reason to use 72 volts, that 48v is more than enough. Bah humbug!

xyster said:

the 48v will work up to 55v

Click to expand...

This is what I was told by electricrider. In reply to my query, the owner wrote me that none of their controllers handle 72+volts:
http://www.electricrider.com/parts/controllers.htm
He stated he sees no reason to use 72 volts, that 48v is more than enough. Bah humbug!

Click to expand...

Nobody would ever need more that 640k of RAM....

I think electric rider simply did not have it in stock... either they ran out of them.. or are not willing tp pay what crystalyte wants for them ( Ask me why i know !!! ) ! lol..

A good dealer would have suggested an alternative to this problem......

Hello

Whilst the controllers can be run at 72V they are right near the edge on reliability with the stock fets. They use cheap no name fets in the controllers and I have found at 72V they are more vulnerable to back emfs from the motor. They will work fine at 72V but you have to treat them with more respect at 72V.

I think the 150V fets that Bob mentioned would be a good Idea if people want to regularly run 72V at 40A. I also agree that 48V is enough with maybe 60V tops at 40A being as much as you need on a bike, but of course people always want more.

At 48V the controllers seem bullet proof and I have been running my Kol everyday at 40A for 8 months with no failures or problems at all. I have found at 72V on the Xlyte and the Kols and even the Puma motors that the controllers are more sensitive to blowing, I have also heard this from people that have contacted me off list as well when they try to run the controllers hard at 72V on all manner of different motors.

I am keeping a close check on the motors I test and if I find it to be a problem I am going to upgrade the fets in the controllers with 150V fets, it seems some controllers are ok and others blow pretty much as soon as you run them at 72V.

I would only recommend running the 72V controllers at 72V if you are confident you can A get it repaired or upgraded, or B return it under warranty, Mark has spoken to Kenny about this as I have found some are ok and other are not.

I am going to beef some up along with a current limit adjust, although I suspect that motor back emfs are what is blowing the controllers as some of the spikes at 80V can be very high indeed.

It will be interesting to see how Bob fares as he is going to be running 72V all the time.

Cheers

Knoxie

knoxie,

what will be the fee for replacing my fets ?????


D

Yo

Dont worry we will sort your controller out if it fails, the problem doesn't exist at 48V mate but they are definitely more sensitive at 72V, but not all of them! its a weird thing, maybe as a lot of the Chinese stuff it just simply boils down to QC as always seems to be the case.

I am confident that a bit of an upgrade will really benefit the controllers, I just don't run 72V all the time so I don't see the problem and have only blown one controller myself at 72V whilst really abusing a motor at 72V.

We will beef you up should it need it Mate

P

it is not well known, but some of the 48v controllers are actually the 72v model, depending on who you buy them from. there is at least one vendor who deliberately underrates his controllers to avoid people using them at the higher voltage. have seen a 35A controller with the 55v irf3205 devices in it, but most do have the 100V irf4710.

the latest 72v controller i bought has 160v electrolytics, some of the 48v ones i have seen had 63v or 100v. i think it has changed a bit over time, so you really never know unless you look.

the 40A and 35A are identical, the change to the shunt was made to let the X5 motors have the extra current, the capacity was there already in the 35A controller. As for it just being 2-20A controllers, that is really not quite true. the 20A and 35/40A use the same low voltage regulator, controller chip, and pwm chip and a similar current sensor, but the drive to the fets is a bit different. There was a controller once that used two separate controllers in parallel but this is not it.

when you put two fets in parallel you add up the gate capacitance and the charge it takes to turn the fet on and off. the driver chips used in the 20A controller don't have quite enough capability for the PWM switching of the two high side fets, so they added a discrete transistor buffer stage after the ir2101 driver in the higher current controllers. this stage seems to have enough drive capability to handle even better fets than the 4710 they are using. i have switched in the 4310 and it works great.

-bob

Hi Bob

Yes thanks a lot for your input, I think it may be a good idea to bump the fets up as the controllers that I have seen fail were 72V controllers and had 160V caps and 100V 70A fets, so I was surprised that they blew.

I think the higher voltage rated fet is a good Idea Bob, it seems some of the newer fets have lower on resistance which is a good thing also!

Cheers

Paul

"the 48v will work up to 55v and the 72v unit will work up to 100v"

You're pretty sure about that 55v limit, Bob? I've put about 800 miles on my rig powered by a 48v 20ah lipoly, that charges up to 58.9v. The 4835 controller was pushing a Clyte Phoenix Cruiser motor. I think the controller has indeed finally sizzled, tho. I've ordered another one, a 4840 this time, but maybe my "hot" battery is the problem? Love the performance, BTW. I've read somewhere that the voltage limit on those controllers is 60v, in which case I should be OK?

The 72V controller often fails to work at 72V, let alone 100V, which is why there have been so many threads about modifying it. Also, the voltage can spike, so you need FETs that are rated for well above the actual voltage you're running, from what I understand.

Hi Steve

Yes on paper they are supposed to but many fail when being used at 72V, esp Lipo as they dont sag and they settle at 83V, I have seen so many of them fail at 72V its unreal, the only way they can be reliably run at 72V and 35 amps is by fitting better fets and properly insulating the fets from the heatsink as it seems that the rubber insulation breaks down and the tabs on the fets short to the case quite quickly at high power levels.

I found this after a lot of testing and messing about, some of the older controllers are ok but many of the newer ones are terrible.

I have a 150V controller that I modified myself, fitting 150V 80A fets and its working great so far.

Cheers

Knoxie