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What EVSE to replace dead Origin/ChargePoint?

Posted: Fri, 13 Jan 2017, 13:30
by jeffthewalker
reecho wrote: Inside the earlier version of the Nissan/MMAU EVSE..

Note the transformer. It may be able to be swapped easily for a multivolt version...??

Google Drive link


There is a relay inside that is 12V. The 19.6VAC would be rectified and used to supply the relay, the plus and minus 12 for the comms and 5V for the processor.

What EVSE to replace dead Origin/ChargePoint?

Posted: Fri, 13 Jan 2017, 14:07
by Johny
Adverse Effects wrote: output 19.6VDC that seems strangely a very specific and odd voltage
It gives enough headroom for a 12V regulator. Note the heat-sunk regulator type device (TO220 case) on the upper left.

Edit: As jeff says - rectified. It's 19.6VAC now I look again.

What EVSE to replace dead Origin/ChargePoint?

Posted: Fri, 13 Jan 2017, 16:23
by coulomb
That's a 50 Hz transformer. You don't see many of those any more. [ Edit: in consumer goods. ] Transformers only work on fixed AC voltages, in this case 230 V and 19.6 V.
Without a lot of work, the best you could do was a transformer with 2 120 V primary windings, and a double pole double throw switch of some sort that arranges rhe windings in series for 240 V operation, or parallel (with care for the correct phase) for 120 V operation. Sadly, it's all too easy to accidentally use the wrong switch position.

It might be possible to use a wide input DC power supply, providing some 27 VDC (19.6 V x sqrt(2)). A 24 V adjustable output model turned up to maximum might just do. The rectifier will not harm anything, merely dropping a volt or two. But that presumes that nothing is expecting AC. It's a reasonable guess, but not guaranteed.

What EVSE to replace dead Origin/ChargePoint?

Posted: Fri, 13 Jan 2017, 19:11
by jeffthewalker
coulomb wrote: That's a 50 Hz transformer. You don't see many of those any more. [ Edit: in consumer goods. ] Transformers only work on fixed AC voltages, in this case 230 V and 19.6 V.
Without a lot of work, the best you could do was a transformer with 2 120 V primary windings, and a double pole double throw switch of some sort that arranges rhe windings in series for 240 V operation, or parallel (with care for the correct phase) for 120 V operation. Sadly, it's all too easy to accidentally use the wrong switch position.
Keeping the LEAF supplied EVSE "as is" is important to me as it is my primary charging option.

To be able to use solar(/storage) I will go ahead and design an EVSE based around the OpenEVSE kit. I will build a PIC based controller to follow the solar output starting at the J1772 minimum of 6A at 120V which is an excess solar requirement of 720W. If the solar output is handling that well, I will up the draw one amp at a time and follow the "excess" solar and I will be able to leave the LEAF "on the charger", unattended, for days at a time. I will be using a 120V 3000W PSW inverter so I will limit the maximum draw to 2400W (absolutely necessary on these 35+°C days).