03/12/2021
JChargers....
What is a JCharger?
Any electric vehicle charger or system that allows for the use of a J1772 public charger plug as it's AC input.
Simple.. no charger cable. Just get it close and plug your EV into a level 2 public AC Charge port. Same place you charge your Leaf or Tesla.
The technical point is that a J1772 is only a 208/240 single phase supply. You can't split a leg to get 120. Since you can't run current down the Ground... it would trip the GFI feature.
The hard point is getting a decent charge power in a small enough volume to matter. You have to 240 rectify, 240 isolate, and then buck down to your EV battery packs needs, keeping aware of the BMS Lithium needs, and getting a serious amount of charge power into your smaller EV... So... you have to put a few cubic feet of power electronics... into a manageable volume, and cool it enough to keep it alive. I have a pile of EVs.. all have different battery packs and voltages and chemistries, all need a hand tweaked manually adjusted charger to fill up with. I want a single J1772 handle to charge them all. Not a dozen setups on a 15 year old PFC40. So this PCharger has to be small, powerful, Iso, and have a programable, and scan able charger. So Everything I have done to date in a coffee can... Kinda like the Minibike from hell BLDC drive, but a Charger. Small stupid powerful , smart. Meets all codes...and common sense safety. And doesn't have 25 lbs of cables hanging off it... Same socket for every EV.
Think I can sell a few?
What power levels and voltages are needed?
12 to 400 volts? Input is from a J1772 EVSE, but My stuff also runs on 120VAC if, you can get it to the Jsocket. Clearly I will have current control by the pilot signal active.
These Jchargers will have many of the same features our PFC charger have now. But with Iso. that limits some currents and voltage to the limits of a internal high frequency transformer. So doing 12v to 450v on a single design, like I can do with the PFC stages is not all that possible. I will have to build to a range of voltages, and currents, and not cover ALL in a single build. They will be 1/4 the volume of our current chargers, and most likely will be under 5kw. More like 1Kw for the 12 to 24volt crowd. I see this as a charger for the under 96 volt EV. Since 30 amps of 240... that's what a standard J1772 port can move... 1800 watts will allow for 4 JChargers to be fed by one Public Card swiped connection. Dreaming here... But doing a 1800 watt Jcharger seams prudent. I am starting with the old PFC15i parts.... and shrinking them down to a 6x6 cube, the length will depend on the needs. More as I refine my ideas. Hope to show a proto type in hours.
