So I killed my DrainBrain again...

M

Mathurin

100 kW
Joined
May 24, 2006
Messages
1,166
Location
Quebec
Last time I'd plugged a motor straight and it died when I flipped the switch, with Justin's help shorting out two pins to the backlight led fixed that. Awesome. (it was that or digging out stuff to change said led, and he made it sound like it sucked so I opted not to).

Well this time I was checking voltage on a battery pack that was charging, except the second time I did that I'd accidentally reversed polarity and it did a spark. Uh oh. But doesn't it have 100v reverse polarity protection or somesuch? Anyways it's dead Jim, and I'm an equine technologist, not an engeneer. Soo, I shot another email to ebikes.ca and we'll see what happens.
 
nutsandvolts said:
...(seems sacrificing parts is standard when you play around over 72V).
Click to expand...

Only if you act like a bull in a china cabinet or push further than spec. I've been running at 84V topped off charge for a while now and no problems. I was told my controller wouldn't like > 85V, so I stay below that limit. Otherwise it's just another voltage. Even if you've got just 12V batteries, you still have to be careful of shorting the terminals.

Sorry to hear about your DrainBrain. My 1st CA will arrive this week, so I'll take care in installation.

John
 
John in CR said:
I've been running at 84V topped off charge for a while now and no problems.
Click to expand...

Ditto with 4110s. 87v no problem. My CA is likely not pulling the 5v power correctly though because it's reading 100+v (even though I know it's only 87v) and the screen fades away to nothing. Anything under about 90v and it reads just fine and correctly at that. I think I affected the 5v power source by applying too much heat to the shunt area when modifying. All wire connections are secure so I think I partially fried a trace or something. Beyond me.
 
Welp, I received an email from Justin (!) telling me the reverse voltage diode probably died along with the LED, and the spark probably meant really bad things. He offered me a rebate on a new one, very cool considering it was my fuckup that killed it. But it seems it's really dead, so now I need to find an appropriate funeral for it. Maybe give it back to him when he stops by Doctorbass'es place? Kill it with gasoline and a lighter? Fill it with expllosives and turn it to dust? Dunno.
 
Keep it please! 8)

Mine also had trouble tonight!..

No prob at 89V or 75V.. but this time at 99.8V it died instantanuously when i put the switch on.. Why?... .. o the spec that's indicated +100V -100V.. so it should operate?

Maybe it's my controlelr that dont supply it correctly with 5V.. and at 100V , the 5V may increase too much?.. unfortunatly the controller wiork nice at that voltage.. but not the cycle analyst...

Any idea??

I would really love to get the schematics of the input voltage area on the little C-A pcb.. the part with the "big" square transistor.. i think it's thisone that could have blow?.. maybe it's a voltage regulator?
 
nutsandvolts said:
Looking at the ICs on mine under magnifier ... this is DB2Rev7 board ...

Microchip PIC16F690 microcontroller, brain of the drainbrain
Microchip MCP6002 dual opamp
Microchip MCP607 dual opamp
ST Micro MJD112 darlington power transistor

That last one is perhaps what you are referring to?
Yeah I think its a DPAK package, this one
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=497-2462-1-ND

Doc, FYI I have a small SMT soldering oven, if you ever want to use it, you are welcome
Click to expand...

Thanks for this offer!

Regarding for the specs of the darlington, i can see that the MAX breakdown voltage is 100V.. hummm!.. so i condiser that using it at 100V is too close to the breakdown voltage and is risky..

I just wonder if Justin consider 100V the max allowable voltage in the spec of the cycle analyst
even though their breakdown limit is 100V too .. that's strange to me...
 
nutsandvolts said:
There appears to be NPN darlington power transistors in same package (DPAK) rated 350V 4A instead of 100V 2A, ON semiconductor (motorola) NJD35N04, not sure about compatibility though, I suppose Justin will chime in eventually.
Click to expand...


great find for the 350V.. but i just wonder if it fried and gors short.. if so, that would mean that the 5V would have reached 100V and blown every 5V supplied IC component... :(
 
Doctorbass said:
Keep it please! 8)
Click to expand...

Actually last I wrote to Justin I mentionned it would be awesome to meet him at your place, he replied that with the help of your equipment it should be possible to figure it out! So, we'll see, it would be pretty cool to fix it. Also to add a red backlight
 
No prob!

I know hor to mod some normal led to fit into LCD!..
 
Mathurin said:
Well this time I was checking voltage on a battery pack that was charging, except the second time I did that I'd accidentally reversed polarity and it did a spark. Uh oh. But doesn't it have 100v reverse polarity protection or somesuch? Anyways it's dead Jim, and I'm an equine technologist, not an engeneer. Soo, I shot another email to ebikes.ca and we'll see what happens.
Click to expand...

So... you're not using black and red powerpoles? I have powerpoles on my battery(they're connected together), and accidental reversal is pretty much physically impossible.
 
nutsandvolts said:
Hey Doc, Justin confirmed that a 350V NPN power transistor in DPAK package would work with his circuit. The one I mentioned was 4A versus 2A on the original 100V part, both are fine and are over-rated as only milliamps are required. To support 200V, this transistor and few other part changes are required, basically some resistor changes I think.
Click to expand...


Thanks for the info.. but i'll wait for Justin that should arrive at Quebec soon.. This time i'll keep it as is without opening it.. so Justin will be able to judge what happened ..why it blown instantanuously at 99.8V.. and that it just worked fine at 88V few minutes before...
 
nutsandvolts said:
Doc, you can get parts couriered via purolator from digikey with delivery next day.
So if you find out right away what parts you need, maybe you can get it repaired
and 200V capable. I kinda doubt he carries SMT resistors with him. But then again,
Justin is full of surprises, maybe he does.
Click to expand...

Thanks for the digikey idea.. i've always though that it is complicated top order drom thes and that the shipping cost is too high with(at least when using their shipping calculator)...
I have many electronic component in stock including variety of smt on different used pcb.. i dont bother with that :wink:

Now the main problem is that i dont know if it's only the dpak transistor or more component.. like the pic orothe zenner..or lcd controller.. i just hope the damage are low...

Doc
 
And now it's alive again! Justin frocked wit it for a while, seemed to enjoy it. the reverse voltage diode was shot and something was still amiss after replacing it. Turns out there was a blown resistor and indeed the back light LED was dead. I was half dead too at this point, laying on the floor in pain. After a while he shows it to me with a big smile on his face, red back light like I'd asked for too! Justin is magic!

 
yes, and red doesn't kill night vision.
 
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