Paul & Sabrina's cheap DIY 144v motor controller - Page 335 - Fuel Economy, Hypermiling, EcoModding News and Forum

steiner · 04-19-2010, 10:12 AM

Paul,

The charger board looks nice. Do you have a seperate thread on it or just posting the information here? I am interested in the specs and any schematics you might have. I already have a BMS (Peter Perkins design) but I do need a charger that I can communicate with.

Rick

MPaulHolmes · 04-19-2010, 10:43 AM

Hi Rick! It's a series of like 8 screen shots for the schematic. Or you can download pcb artist and I can send you the schematic that way. Do you have an email I could send them to? I don't have a thread for it yet. I've been sort of sloppy on the documentation. Just sort of doing it.

MPaulHolmes · 04-19-2010, 12:18 PM

Hi Louman! I forgot. you wrote a while ago. I forgot to respond. I had run out of microcontrollers, and I placed an order for more but they aren't here yet.

The bms will be posted. I have a thread for it, but I've been slacking on that.

How old is your chip? If it's the earlier version, when the 12v is powering the control board, the light could be off if the code wasn't running (like if an error, such as no throttle, no current sensor, etc...). Now, when there's no throttle and no sensor, it blinks. The old chip blinked when everything was hooked up right.

You could check pin 15. That's the pwm pin. My guess is that it will show 0v. Do you have a serial port on your computer? You could see what version it is that way.

MPaulHolmes · 04-19-2010, 01:23 PM

Hi Louman! The august chip doesn't have serial communications.

It was just a "put it in a completed controller and drive away, praying that you made no mistakes." hahaha. That would be called version 0.01. It works fine, but still.

MPaulHolmes · 04-19-2010, 01:41 PM

YOu would need to attach a current sensor to it (or fake the signal) and also attach a 0-5k pot (or twist the pot wires together).

Paul

Weisheimer · 04-19-2010, 08:18 PM

Quote:

Originally Posted by MPaulHolmes

Do you have an email I could send them to?

Paul,

Would you do me the kindness of sending the SR schematic file too?
You should have my e-mail address, but let me know if you don't.

Thanks
Mark

bones007 · 04-21-2010, 12:10 AM

I have a question about pre-charging the controller. Is there any reason why we shouldn't just put a resistor in parallel with the main contactor and just leave it there. If we do so then the controller caps will always be charged up and there is no need to wait some time before closing the contactor.

I remember a long while back that there was some problem with the order of turning things on: Turn controller on, apply high voltage, run for a while, remove high voltage, shut down controller. Is this the reason for disconnecting the pre-charge resistor? But, wasn't this solved when all the opto-isolators went in (ver 2c). If so why are some of you disconnecting the pre-charge resistor using a relay?

ga2500ev · 04-21-2010, 08:22 AM

Quote:

Originally Posted by bones007

I have a question about pre-charging the controller. Is there any reason why we shouldn't just put a resistor in parallel with the main contactor and just leave it there. If we do so then the controller caps will always be charged up and there is no need to wait some time before closing the contactor.

It's a safety issue. Caps charged to battery voltage can give quite a zap. So having a precharge resistor that can be switched by relay means that the car can sit with the caps discharged (and relatively safe) when not in use.

It's only a few seconds anyway.

Quote:

I remember a long while back that there was some problem with the order of turning things on: Turn controller on, apply high voltage, run for a while, remove high voltage, shut down controller. Is this the reason for disconnecting the pre-charge resistor? But, wasn't this solved when all the opto-isolators went in (ver 2c). If so why are some of you disconnecting the pre-charge resistor using a relay?

The above has always been my understanding as to why.

ga2500ev

Tweety · 04-21-2010, 08:47 AM

That plus the precharge resistor tends to build heat as it's a bit owerwhealmed by the current... So leaving it connected might not be a good thing long term...

dave koller · 04-21-2010, 03:42 PM

Quote:

Originally Posted by Tweety

That plus the precharge resistor tends to build heat as it's a bit owerwhealmed by the current... So leaving it connected might not be a good thing long term...

In my humble opinion, once the caps reach pack voltage - there is no current drawn through the pre-charge... and keeping the value (resistive) high should not overheat it much in the initial stage of pre-charge - just take a bit longer..

I wondered if cl-30 inrush thermistors would be a good,fast, pre-charge alternative.. I use them to cushion the inrush to the DC/DC - any thoughts?