Paul & Sabrina's cheap DIY 144v motor controller

[Johnstan]

Paul I am still trying to read your 150 odd pages have just sent my second donation.
Re attaching mosfets to heatsink the Curtis 1231c screws the center leg to the heat sink attached photo of my blown Curtis. At 72 years age your pages have convinced me to try to learn basic electronics circuitry so I can keep up with you. A story on my car is on the latest AEVA newsletter

[squiggles]

Originally Posted by NiHaoMike

For the power stage, what about oil cool it? Put it in a sealed container, seal up the power and control lines, connect a cooling system with a pump and transmission cooler, and fill it with transformer oil. Something like one of those speciality PC power supplies. JonnyGURU.com - Power Supply Reviews and more! - Reviews - Koolance PSU-1200ATX-12S Liquid Cooled 1200W power supply

Just checked out that power supply, please tell me it was released on April 1.

[NiHaoMike]

Originally Posted by squiggles

Just checked out that power supply, please tell me it was released on April 1.

It actually exists (and a newer revision is out) and is intended for multi CPU workstations and servers. It would be sized about right for an 8 CPU Britney workstation with a high end Nvidia Quadro back when that was considered the best out there. Now, it would be good for a large Xeon workstation with 2 or 3 of the latest Quadros in SLI.
Water cooling systems, pc liquid cooling kit, cpu, video card, hard drive

It's the PC equivalent of a V12 but it works great in the right application. Can get great efficiency for what it does, too.

[dcb]

And you could plumb the radiator under your desk and displace one of those little foot heaters

[wjdennis]

I have a question about those PC power supplies. Can you connect all the 12V outputs together and get 85A to power one device? Are they regulated so that each leg will not supply more than its rated amperage?

Thanks.

Bill

[slurryguy]

DEATH WISH 9
Starring Paul "Charles Bronson" Holmes.


*****WARNING!!! EV Enthusiasts and Electronic Geeks should ask small children to leave the room before reading further. This list gets pretty ugly. Adults with weak stomachs may not want to read it at all. The writer of this list is not responsible for any angry rages by overly sensitive readers or for anyone losing control of their bowels. Each reader is responsible for cleaning their own pants if they lose control. YOU HAVE BEEN WARNED!******


Following is a list of the most common, most horrendously abusive ways I could think of that might possibly KILL a controller (and/or other expensive parts of an EV.) My questions to Paul "Charles Bronson" Holmes, is how would the controller handle each situation? Will the controller fail? If the controller fails, will it fail safely?

1. Installer mistakenly hooks the tracktion pack up to the controller with reverse polarity.

2. Installer mistakenly hooks the Accessory Battery up to the controller with reverse polarity.

3. Installer mistakenly hooks traction pack voltage to the Accessory Battery input terminals.

4. Accessory Battery (or traction battery) accidentally hooked up to the throttle input terminals.

5. Installer mistakenly shorts the motor cables to each other by attaching both of them to the same terminal on the motor. Somebody gets in the car, turns it on, and FLOORS IT for 30 seconds.

6. Installer mistakenly hooks the motor to the battery input terminals, and the traction pack to the motor terminals. (or any other possible screwed up combination of connection FUBAR.)

7. Somebody turns on the car, leaves the parking break fully engaged, puts the car in gear, and floors it for 30 seconds.

8. After watching a Football game with a group of guys everyone is getting in their cars to head for home. Of course... the EV driver can't just drive away. He must try to show off. He turns on the car, and tries to do a burnout (it's a testosterone thing) by riding the brake and flooring the accelerator simultaneously.

9. While waiting at a stop light, an extremly attractive girl walks by. Instinctively the guy that's driving decides to show off and rev the motor while the car is sitting in neutral. (It's a testosterone thing.) This person floors it for 30 seconds. (Motor grenade alert?)




I'm confident others may come up with other horrific possibilites that could be added to this list. Feel free to do so.

I think it's very reasonable to think about what happens to the controller when it gets abused in any of these ways.

[dcb]

Build a few and try all those scenarios and get back to us.

[slurryguy]

Originally Posted by dcb

Build a few and try all those scenarios and get back to us.

And post the video of each test, right?

[nubie]

Assuming that you are going to blow up certain parts, like the legs on the Mosfets, I would imagine that you would just go through and replace whatever part was damaged.

It should be designed so that a massive failure would make fire or thermal runaway very rare.

As long as the board isn't damaged you can probably repair most anything. I would expect it would be cheaper to provide protection for the control circuit due to the low power draw.


At the end of the day you just can't have clueless people hooking up the car. Anything is dangerous if you do it wrong.

[MPaulHolmes]

These are really really good questions! Let's keep this up! YOu should be a beta tester! I'm about to go out, but I'll try to answer the easier ones before I go. (I'll add to it later today)

2. Control section reverse polarity:
SAFE & NOT DESTRUCTIVE -
There is reverse polarity protection. The controller wouldn't turn on, and nothing would break.

4.
If 12v supply connected to throttle input:
SAFE & NOT DESTRUCTIVE - There would be at most 0.01 amps flowing. No power to controller. You would just sit there.

If 144v supply connected to throttle input:
SAFE & MILDLY DESTRUCTIVE - There would be at most 11.25 watts being dissipated through a quarter watt resistor. The resistor would fail, and it would eventually open like a fuse. Replace resistor and possibly burned up PCB tracks on control board.

7 & 8:
Flooring it while parking brake or brake on for 30 seconds:
SAFE & NOT DESTRUCTIVE - (See Ben's video of version 1)
Here's where the hardware overcurrent protection comes in handy!
The current would quickly shoot up to 500 amps, and would hold around 500 amps (or a little less) for 30 seconds. Your batteries may be sort of angry at the end of the 30 seconds. If the controller gets too warm, it would automatically lower the current limit based on the temperature.

9. Flooring it in Neutral:
DESTRUCTION OF MOTOR (But at least the controller will be fine. hehehe) -
The motor would over-rev and be ruined. In the next version, I'm going to add an RPM sensor to control max RPM.

So, in the next version, this would result in the motor revving to maybe 6000rpm, and holding around 6000 rpm. The guy would feel really cool!

MORE LATER!