Paul & Sabrina's cheap DIY 144v motor controller

[TheSGC]

I like the idea of multiple beta testers to get a broad range of information. I'd be willing to test if there is a need on my 96 volt Civic once I get my FB1-4001 installed. I know have a Kelly and I could do a straight comparison at 96 volts between the two.

Anyways, I'm itching to see version 2 and find out what the real cause of the bust was.

[ga2500ev]

Originally Posted by MPaulHolmes

I also am adding a zener diode (I never knew what those really were until today. Don't tell anyone! It's a secret. I'm the "expert" hahahaha!) to not allow voltage spikes from gate to source. It will clamp the voltage from gate to source to no more than 20v. The voltage from gate to source can now freely rise to 20v, and then all of a sudden, BAM! NO MORE! HAHA! If even a small voltage spike of 30v hits the gate, it can destroy the mosfet. That could have been what happened last time. Now, that potential problem is eliminated!

!

Two quick notes on the zeners:

1) Make sure that the zener is tied after the gate resistor. Zeners need to be current limited, or they release their magic smoke.

2) Do a quick power rating check to make sure that the zener is beefy enough, If you have a 20 ohm gate resistor and are clipping the voltage to 20V, then a 30V spike will draw a half amp's worth of current (30V-20V)/20 ohms and would need 5W to dissipate.

ga2500ev

[MazdaMatt]

Roger, thank you for your explaination of the pack voltage details... you filled it in a little better than me

SGC, it would be great if we could do some multiple voltage level beta testing

ga, I don't think you need to worry about that. We are not trying to protect from someone hooking up a 30-volt power supply. We are just trying to protect from spikes. A 1us spike may generate 5W for 1us, but that won't generate any heat. As long as it can handle the peak current and voltage that we need to clamp, it is no issue.

As for prototype PCB professionally made... Did I ever mention that is exactly what the company that I work for does? I had a word with someone here. THIS IS NOT OFFICIAL INFORMATION. If Paul were to source the parts from Digikey and source the boards from PCBCart.com or one of the other el-cheapo custom board houses and put all that in a box and send it to us... we could ship him 10 control boards, wave soldered for under 500 bucks. This would be visually inspected, no special certifications, etc. The more we make, the better the "per board" price. The more we do (sourcing parts, surface mounting, post-testing) the more cost.

So Paul... PM me if you are interested. I would not bother with less than 10 as the fixed costs would make the board price a little silly.

On the other hand... I'd seriously find the time to solder everything by hand myself for Beta testers...

[KijanaKiume]

Dude. One word: WOW I spent 7hours reading this today and all i have to say is wow. You did it. WHOOT WHOOT!!! Cheering you on!

[MPaulHolmes]

I talked to Fran, and I have a few things to change now. Really sneaky subtle things! It's all pretty easy to change though. Nothing too hard. After a few more iterations to make sure everything is good, I'd like to breadboard it to try it out before getting PCBs made.

Thank you Kijana! This thing is getting really long, huh! 7 hours! geeze!

[KijanaKiume]

yeah. im on spring break so i was bored. read all of ben's electric metro coversion. then found the link for this and read it all. yikes huh? its pretty darn sweet.

[Wherewolf]

Originally Posted by MazdaMatt

On the other hand... I'd seriously find the time to solder everything by hand myself for Beta testers...

What I personally think would be really cool: Make up some basic instructions (maybe videos?) that would show techniques for hand soldering different types of components - when to use more heat, when to use less, the use of flux , desoldering, etc....I know there are clamps to dissipate heat to protect components, what to buy, additional tips, resources, etc... to help the others involved in this.....just a thought....
Shared Knowledge is Best...Put the forums to the Test.

Wherewolf

[esoneson]

Wherewolf,

I found several soldering instructions on YouTube and I think there are some at the instructables web site too. Google is my friend.

Eric

[TheSGC]

I have no problem soldering components together, but I do have a problem with the milling of the PCB. I don't have the tools to do it, but this summer I might play with PCB liquid etching.

Maybe if "Beta Kits" were made, like all the Buss Bars and PCB was already cut to spec, then the the "Beta Kit" tester just soldered everything up. It would make an excellent test of the kit from start to finish.

[Wherewolf]

Originally Posted by esoneson

Wherewolf,

I found several soldering instructions on YouTube and I think there are some at the instructables web site too. Google is my friend.

Eric

I understand that there are instructions out there, I was thinking more of specifics related to this project - any tricky issues with soldering the components particular to this controller - caps, mosfets, diodes etc....

Wherewolf