DIY Open Source EV Charger

[watt-a-mezz]

Originally Posted by apowers

My charger is bolted to the vehical and I have a ground fault breaker to interupt
the power, just in case. It has worked a time or two when the acid made a short
to the frame. I have since isolated the batteries better.
Alvin

Alvin, you had said a few pages back, you had built one of these. I was wanting to try, but not sure what to do for the inductor. What did you
use? Thanks, Watt

[apowers]

watt-a-mezz
I used the transformer from an old microwave. The "E" and "I" are welded together
but can easily be hack-sawed apart. The weld is soft and only about 1/16" thick.
I had been using a light dimmer to control voltage for acceptance part of charge
The dimmer will not hold the voltage down anymore. I am in the process of basically
building a controller to replace the dimmer. I am using athe MC33033 chip (not smart)
but should work...maybe. I used the fan from the microwave to cool everything.
I am using the small transformer from the control board of the microwave to power the contoller from the mains.
I know this is not how the Bonn charger was designed but I did not have
any luck with multiple leads from the inductor. Lee Hart had told me that the transformer
from an old battery charger would work.
Alvin

[jackbauer]

Laying out the box. Fan will be installed above heatsink. Here we have some welder , plasma cutter , computer , tv , power supply and pinball machine parts

[watt-a-mezz]

Originally Posted by jackbauer

Laying out the box. Fan will be installed above heatsink. Here we have some welder , plasma cutter , computer , tv , power supply and pinball machine parts

Impressive collection, I would not have a clue how to hook it all up. I wanted
to ask if you could tell me how to wire up a multiple voltage charger
transformer, to run in a bonn type charger? It has 1 input and 3 tabs
for the switch, 2 E and a loop on the other side. Just want to be sure
I dont mess it up. Thanks, Watt

[esoneson]

Originally Posted by jackbauer

Laying out the box. Fan will be installed above heatsink. Here we have some welder , plasma cutter , computer , tv , power supply and pinball machine parts

You a magician, Jack Bauer, make that magic happen!

Eric

[jackbauer]

Originally Posted by watt-a-mezz

Impressive collection, I would not have a clue how to hook it all up. I wanted
to ask if you could tell me how to wire up a multiple voltage charger
transformer, to run in a bonn type charger? It has 1 input and 3 tabs
for the switch, 2 E and a loop on the other side. Just want to be sure
I dont mess it up. Thanks, Watt

I guess your wanting to use the transformer as an inductor to limit the charge current? I'm guessing its a triple voltage transformer from your description. If so connect the live to the 0v tap and use the other 3 as outputs. The different number of turns will give different inductance and thus higher or lower charge currents. If you can post a pic of the transformer mabey i can give a better description. You might want to consider a sodium lamp ballast. Ready made current limiting inductor

[apowers]

watt-a-mezz
On the diagram of the bonn charger you rewind the core and bring out taps.
The end you start with is #1 it comes ac hot. the other taps should give different
voltage. any one of those taps you choose goes into rectifier ac. The neutral ac
from the mains goes into the other ac on rectifier. The switch between the inductor
and rectifier lets you toggle or select a different tap. Like I said I did not get any difference in voltage from different taps. (must have done something wrong)
Alvin
edit : If you are using a microwave transformer. Do not hook power to it
as is, those things output 2000 volts and will kill you.

[jackbauer]

What about a saturable reactor like on old welders:
Saturable reactor - Wikipedia, the free encyclopedia

[watt-a-mezz]

Hello Jack & Alvin. Thanks for the feedback. The transformer I wanted to
try is from an old Harbor Freight Multiple voltage 12v 6A charger. It had
a switch to change from 12v 6a, 12v2a and 6v 6a. the thing weighs about
about 8 lbs. I tried to take pics of it, and they are on Photobucket.com
(watt-a-mezz, nissan ev). Seems to be fairly straightforward, input(black
wire) output to bridge rectifier(red wire). Every time I think something is super simple, it comes back to bite me. As evil as this thing looks, I
dont think I will be testing it off of a wall socket. Thanks again, Watt.

[watt-a-mezz]

Just found out my photobucket account was messed up. Wanted to
thank everyone for their help. Will keep working on the charger. Watt.