Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Paul & Sabrina's cheap DIY 144v motor controller

MPaulHolmes · 05-11-2009, 03:45 AM

I'll get that stuff up on Adrian's space. Thank you Adrian!

I've been thinking about acceleration and deceleration. Curtis uses a 3.5 second ramp down from full throttle. I thought that seemed really stupid, but I think they do it so the car doesn't feel like the power got shut off like a light switch each time you take your foot off the accelerator. It made for really jerky driving. I never noticed how often I took my foot off the accelerator while still moving. It's actually pretty annoying to feel that jerk when there's an immediate loss of torque. Right now, I have deceleration happen 4 times faster than acceleration, and it's fast enough that it feels about how it does in a regular gas car.

The benefit of granny mode is that it makes it very easy to have really really smooth control at low rpm. Man, I always get ideas while typing! You can have the best of granny and Grand Prix Mode (for grand prix people only). In Grand Prix Mode, If the throttle changes fast, then change PWM stuff fast, if the throttle changes slow, then make everything as if it were in granny mode, with the full 8192 resolution (or whatever) of PWM changing slowly. I've been making the fine PWM signal change by at most 1 each throttle read, which makes for ramping similar to the Curtis, which has a minimum ramping time from 0 to full PWM duty in 3.5 seconds, and max ramp setting of 0 to full PWM duty in 15 seconds.

I think it would be pretty easy to make the changes to allow for the various modes. That's a good idea, Eric! We could have the mode be inputted through the RS-232.

By the way, the gerber files are done for the control section. Heck ya! They were all squishy too, and my son ate them. Then he took his gerber knife, and gerber baby food, and gerber files and blah blah blah.

Here's the deal. I'm sending the gerber files to futurlec, and the cost is about $35 each board. I'm getting 3 boards done. The expert with all the fancy test equipment is assembling them, and doing testing on them. The cost of components on the control board is about $43.00 or so. Whatever the heck the BOM says on the website. I have 30 200v diodes, 10 mosfets, maybe 20 old capacitors that were removed from the blown up controller, and lots of 3 ounce copper pcb.

I'm going to do Ben's controller for free, because I have pretty much all the parts for 1 controller, thanks to all the donations. So, should I wait for awhile to make sure nothing blows up? I might secretly set his on granny mode. haha! Or are there 2 people that want to pay for parts to the other 2 controllers? They could either put them together themselves, or I could do it. I sort of want to test the new alternate power section layout concurrently with Ben's controller, which has the old one. The problem is, I don't have the money to make the other 2! Does anyone want a controller for the cost of the parts to build it? This is a 3 controller limited edition run. hehe. Ben's, and 2 others, on a new and dramatically improved control section. Now, could it last a week, and then blow up? Sure! I doubt it this time, because there has been a lot of thought put into the possible failure modes. The guy that made the anti-land-mine machine, the expert with all the fancy test equipment,... etc.. They have all given their help.

I can't guarantee that all 3 would be done really fast. My main work time is during my son's nap, which is from 3pm to 4:30pm each day. Maybe I should figure out how much they will cost, and then see if anyone wants to pay that. One thing I'm really curious about is whether or not the 3 ounce copper is enough for a 500 amp controller. My guess is that it is fine. I know that 4 ounce is good up to a 600 amp controller, so 3 ounce is probably fine for a 500 amp controller. Lord knows I have enough of that crap in the garage. Just no more 4 ounce stuff.

Hey Wolfman! Where the heck did you order that 4 ounce stuff, anyway? With the alternate layout, 6"x8" is plenty! The alternate layout also means I can use the copper bus bars you sent too! Heck ya, dude! They will all soon be in their own controller. I'm also going to tin them with TINNIT Bright plate. That will be cool.

05-11-2009, 03:45 AM	#1184 (permalink)
MPaulHolmes PaulH Join Date: Feb 2008 Location: Maricopa, AZ (sort of. Actually outside of town) Posts: 3,832 Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000 Thanks: 1,368 Thanked 1,202 Times in 765 Posts	I'll get that stuff up on Adrian's space. Thank you Adrian! I've been thinking about acceleration and deceleration. Curtis uses a 3.5 second ramp down from full throttle. I thought that seemed really stupid, but I think they do it so the car doesn't feel like the power got shut off like a light switch each time you take your foot off the accelerator. It made for really jerky driving. I never noticed how often I took my foot off the accelerator while still moving. It's actually pretty annoying to feel that jerk when there's an immediate loss of torque. Right now, I have deceleration happen 4 times faster than acceleration, and it's fast enough that it feels about how it does in a regular gas car. The benefit of granny mode is that it makes it very easy to have really really smooth control at low rpm. Man, I always get ideas while typing! You can have the best of granny and Grand Prix Mode (for grand prix people only). In Grand Prix Mode, If the throttle changes fast, then change PWM stuff fast, if the throttle changes slow, then make everything as if it were in granny mode, with the full 8192 resolution (or whatever) of PWM changing slowly. I've been making the fine PWM signal change by at most 1 each throttle read, which makes for ramping similar to the Curtis, which has a minimum ramping time from 0 to full PWM duty in 3.5 seconds, and max ramp setting of 0 to full PWM duty in 15 seconds. I think it would be pretty easy to make the changes to allow for the various modes. That's a good idea, Eric! We could have the mode be inputted through the RS-232. By the way, the gerber files are done for the control section. Heck ya! They were all squishy too, and my son ate them. Then he took his gerber knife, and gerber baby food, and gerber files and blah blah blah. Here's the deal. I'm sending the gerber files to futurlec, and the cost is about $35 each board. I'm getting 3 boards done. The expert with all the fancy test equipment is assembling them, and doing testing on them. The cost of components on the control board is about $43.00 or so. Whatever the heck the BOM says on the website. I have 30 200v diodes, 10 mosfets, maybe 20 old capacitors that were removed from the blown up controller, and lots of 3 ounce copper pcb. I'm going to do Ben's controller for free, because I have pretty much all the parts for 1 controller, thanks to all the donations. So, should I wait for awhile to make sure nothing blows up? I might secretly set his on granny mode. haha! Or are there 2 people that want to pay for parts to the other 2 controllers? They could either put them together themselves, or I could do it. I sort of want to test the new alternate power section layout concurrently with Ben's controller, which has the old one. The problem is, I don't have the money to make the other 2! Does anyone want a controller for the cost of the parts to build it? This is a 3 controller limited edition run. hehe. Ben's, and 2 others, on a new and dramatically improved control section. Now, could it last a week, and then blow up? Sure! I doubt it this time, because there has been a lot of thought put into the possible failure modes. The guy that made the anti-land-mine machine, the expert with all the fancy test equipment,... etc.. They have all given their help. I can't guarantee that all 3 would be done really fast. My main work time is during my son's nap, which is from 3pm to 4:30pm each day. Maybe I should figure out how much they will cost, and then see if anyone wants to pay that. One thing I'm really curious about is whether or not the 3 ounce copper is enough for a 500 amp controller. My guess is that it is fine. I know that 4 ounce is good up to a 600 amp controller, so 3 ounce is probably fine for a 500 amp controller. Lord knows I have enough of that crap in the garage. Just no more 4 ounce stuff. Hey Wolfman! Where the heck did you order that 4 ounce stuff, anyway? With the alternate layout, 6"x8" is plenty! The alternate layout also means I can use the copper bus bars you sent too! Heck ya, dude! They will all soon be in their own controller. I'm also going to tin them with TINNIT Bright plate. That will be cool. __________________ kits and boards Last edited by MPaulHolmes; 05-11-2009 at 03:53 AM..