DIY Open Source EV Charger

[adamj12b]

Originally Posted by apowers

Yes I think it is a transforner. I'm not sure I can use it for anything other than a boat anchor.
Alvin

It looks like dual primary's and dual secondaries. Depending on the winding of it, you might be able to use it for an isolation transformer for an non isolated battery charger. If you wire the primaries in series and the secondaries in parallel you can get a pretty powerful step down transformer.

Did you measure the voltage outputs yet?

-Adam

[apowers]

I put some DC voltage through it from a tiny 9 volt battery. I don't want to kill myself. That is not easy to measure voltage from it . On the primary side there is 4 taps plus a black wire that seems to be a common. The primary is wound with 17 gauge wire 5 in hand and the secondary is 14 gauge 8 in hand. The common wire has some type of sensor or something mounted tight to the coil under the wrapping.

I have a small transformer that I can run some AC through it. The small battery would just sag to nothing. Just tapping the battery contact was giving lots of different readings. It did burn out a small 12 volt bulb just using the 9 volt battery after it was down to less than 8 volts.

This thing weighs 30 pounds. The wire is copper but a magnet is attracted to the core.

Alvin

[KUSAW]

Dear Alvn,
please put small AC voltage, then you'll get the output voltage. after that you will have the N ratio of primary and secondary, just use simple mathematic.....

[flores]

I think DC in a transformer does not work.. or does it?

[KUSAW]

It doesn't work

[adamj12b]

Originally Posted by apowers

I put some DC voltage through it from a tiny 9 volt battery. I don't want to kill myself. That is not easy to measure voltage from it . On the primary side there is 4 taps plus a black wire that seems to be a common. The primary is wound with 17 gauge wire 5 in hand and the secondary is 14 gauge 8 in hand. The common wire has some type of sensor or something mounted tight to the coil under the wrapping.

I have a small transformer that I can run some AC through it. The small battery would just sag to nothing. Just tapping the battery contact was giving lots of different readings. It did burn out a small 12 volt bulb just using the 9 volt battery after it was down to less than 8 volts.

This thing weighs 30 pounds. The wire is copper but a magnet is attracted to the core.

Alvin

Transformers only work with AC. The battery was just being shorted out though the copper wire.

The small sensor you see is most likely a temp switch. When the transformer gets too hot, it will open and cut power. This is usually connected to the primary winding.

The core will be iron. Most likely laminated plates. This would be a low frequency in the range of 50-400Hz.

-Adam

[apowers]

There are 4 taps and a commom on the primary. I connected 125 volts AC to each one. The output with the secondary leads in series is 17.4 volts, 27.4volts, 30 volts,and 48volts. Half of the secondary leads halves the output.

I guess that answers my question, it is a transformer. Thanks to everyone for your time.

Alvin

[jackbauer]

Soon my 10kw water heater .... ooops I mean battery charger will be ready for action. Muhahahaha

http://www.youtube.com/watch?v=RFqI0DLOGFU

[jackbauer]

Mounted the radiator on the enclosure today with a piece of aluminium angle and some 6mm threaded rod. Still not sure if I will mount the radiator in the passenger cabin. Depends on the amount of heat it pumps out!

[jackbauer]

Some more progress on the charger build. Got the control stage built up on a piece of 6mm clear polycarbonate. All of the i/o to the control board are terminated on a piece of barrier strip. Also mounted on the polycarbonate are the display screen and the push buttons. Mounted two epcos 4700uf 400v caps in the main enclosure and a piece of din rail for the input rcbo , earth point and output fuse. Also mounted a 12v 5A dc power supply for the logic and coolant pump.

Can't wait to fire this thing up