Lyen controller not working at 37V

[cwah]

Thanks guys, I'm going to try to remove the R12 resistor and use 1:Comm GND when programming.

[cwah]

This little resistor is sooo small:


How do I desolder that? There isn't even solder on the other side of the board. I may just burn it???

[NeilP]

You are not supposed to be removing that one, that is R12 itself, you are supposed to be looking for annextfa one on the back of the board, a normal one , possibly in a piece of heat shrink sleeving.
Take that off and you will likely have to send it back again
Show us a pic of back of board

[cwah]

Thanks Neil. Lyen contacted me and told me it was the little one with brown red red. I've only found this one:


On the front I haven't found anything that look like this:


Hope it's going to be the right one this time.

[cwah]

Ok, has been confirmed by Lyen. Going to remove it

[NeilP]

If you are going to be workng with this sort of stuff, and are not familiar with colour codes on normal resistors, or the number codes on the SMD resistors

try this little freeware app...Windows only

http://www.schematica.com/resistor_colo ... sistor.htm

[cwah]

I downloaded the program, will use it if I have to desolder other stuff in the future.

It's working at 37V now, so nice

Thanks all and Neil and also Lyen for his advice

[NeilP]

That is good to hear

But one question
Why after buying a high voltage controller have you decided to run at such a low voltage?

[cwah]

Good question!

Why I purchased my controller, I wasn't really sure of the performance my my conhismotor mini hub. But I wanted to reach 30mph. So in case if my 74V set up is not enough to reach 30mph, I can still increase the voltage without having to change the whole set up.

Now, most of the time I won't rum at 37V, I'll use it only for long distance journey in which low speed amd high efficiency is required.

This choice isn't that random lol

[NeilP]

yes, makes sense, but even from 74 volt, you col dhave stil gon up to 24S and 100 volt with the standard controller. just needed the R12 mod, and only then if you needed the regen

[cwah]

Yeah, but I wasn't sure about the voltage I would need. Better to have something adaptable rather than having to change the whole system. I found that the weight was identical to a normal controller, so I preferred to get a higher voltage one for safety

[NeilP]

Yes, se your point, but less current with the high voltage ones, so less acceleration

[Jeremy Harris]

Using a high voltage controller for a lower voltage application also means less efficiency. There is a fairly linear relationship between FET on resistance and maximum voltage, such that 100 V capable FETs will have around double the on resistance (and hence double the losses at a given current) than 50 V capable FETs.

It's for this reason that I changed the FETs in my boat controller (that works at around 20 V max) to IRLB3034 FETs (40 V maximum. These have only 38% of the loss that the 100 V max IRFB4110 FETs commonly used in ~80 V controllers, and only 15% of the loss of the 150 V max IRFB4115 FETs frquently used in 100 V + capable controllers.

If you want best efficiency, then go for a controller fitted with FETs that match your operating voltage range, don't go for a controller with an unnecessarily high voltage spec.

[NeilP]

Ah yes, forgotten about that.

Is this the same controller that you have the 400W for 12mph thread going about or is this a different bike? This could account for a few more watts lost. OK, probably not the full amount, but a little bit here and there, all soon adds up

[cwah]

Yes, it is the same controller. Actually I wanted to be able to transform my 74V8AH battery to 37V16AH for maximum distance when required. But I didn't know that higher voltage controller would be less efficient...

Hopefully, I know that I can always increase the speed and voltage If I want/need to!