Hello To all!!! My name is Miguel and for about 2 years I have worked on this project. (Little by little) I am by no means and expert nor a professional by any stretch of the imagination.
Also this is the first thread I have ever posted any where! So go ease on me. That being said about 3 years ago I wanted to build another project car, and something about cents per mile really had my attention. At first I was going to build an EV but soon realized the parts required was going to hurt
The figure I had in mind of what another vehicle should cost.
Since I wanted to build almost all of the components minus motor/batters for obvious reasons I put the entire idea on the back burner. Till I found a 1971 suzuki TC125 for 100$
Then the conversion hamster started to run. I decided to convert that old wheezing 2 cycle in to something much more quite. And as it turned out MUCH more fast
I started to think about all of the things that make sense to me about What an E-bike should be. First off there's nothing wrong with pedaling a bike, I'm just too lazy to do it. If I'm going to spend the time money and effort to build an e-bike there won't be pedals on it. Second it's always good to have a bit of danger in something you're riding, you WILL respect it much more. Lastly it should look mostly inconspicuous. If it looks crazy and it draws more attention and the fuzz will not approve. Any way I knew that the motor and batteries would cost the most so that's what I got first. The motor I had chosen was a LEMCO D135RAG. Due to its impressive power to weight ratio and compact size The batteries I had chosen was A123 battery systems 20ah Prismatic pouch cell. Due to its continuous current draw of 200 amps and burst rating of 600 amps for 10 seconds. And 3000$ later it had arrived at my house. The motor controller however was up in the air. I had tried several attempts of different styles of motor controllers utilizing mosfets then igbt's all ended up in a puff of smoke. I finally had enough and decided to purchase one off of eBay, that was New Old Stock of a Kelly controller. KDH12600. I'm not a big fan of buying things overseas.
But the controller I purchase through eBay was $124
I had heard of many mixed reviews both positive and negative feedback from the company Kelly controller
And decided that $124 that if it failed I would have a nice enclosure to build one of my own design. remarkably the controller has not failed yet but was never able to blow a 120 amp fuse. "600 amp for 10 seconds"
I will post pictures soon of all the progress, sadly I never took pictures of my self building the frame and swing arm and down tube.
The reason I started this short thread was to show that it's not terribly hard to build a e-bike. With nothing more than a mig welder and an angle grinder and a drill press. And lots of patience. So as far as looks go I wanted my e-bike to look like a bicycle at first glance as to not draw too much attention as I wiz by people on the bike path. For the drive train. from the motor 23 tooth sprocket size 40 chain to a 25 tooth sprocket
With a one way roller type sprag. To a jack shaft with a 13 tooth sprocket to the rim sprocket of 46 tooth sprocket. The entire reason I started this thread was to freely spread the knowledge I've gained over the past years in my purely amateur attempts of power control semiconductor design
As a semi large company manufacturing motor controllers the biggest thing they have to look out for is total cost in whatever model they release. I on the other hand I'm not that unfortunate. As as far as a business model goes this will not make money, as the parts I have chosen are relatively expensive. If you are unfamiliar with any of the terms I'm using or have used Google is you're friend. Checkout subcooledheatpump on you tube as this is where I got a large part of the information. I am a huge fan of a simplistic approach in many aspects of my life. And this controller I've made is no different. I have used an igbt module (qiq0645003) this igbt brick is specifically used as a low side chopper. There is no currant limiting circuit, no type of logic of any kind in fact. The only type of safety I've implemented is a 200 amp fuse. And 2 thermal (75c) switch mounted directly to the heatsink as close as I could get it to the igbt itself, designed to activate a relay to pull the enable/disable pin high/low on the gate driver (IXDD414IP) the pwm sorcerer is produced by a SG3525 module from ebay. I've made all the pcb using pcb droid / paint a laser printer and the toner transfer method. I will provide schematics at a later date. The caps (EGXF161ELL151MK30S) are from mouser electronics x60 at 150 uf giving me 9000uf of capacitance
As for the snubbed caps kemet 1000v 2uf x2