Guru
Joined: 21/06/2018
Location: AustraliaPosts: 1187
| Posted: 12:19pm 08 Mar 2024 |
The controller card is powered using an onboard 12V output un-isolated switching regulator. It accepts from ~ 17V to 75V input and provides 0.5A. There is an option of another regulator type that has similar input voltage span but provides 1.0A
Following that is a small 5V switching regulator fed from the 12V pre-regulator that provides 5V @ 0.5A which is ample for the LCD etc - current requirements for the controller with LCD is less than 0.1A.
The cost for the two regulators is ~ $7.50 (total) from Digikey and probably Element 14 and others. If you plan to run the 2 fans from the onboard regulator depending on their current, budget for 12V fans with a maximum of no more than 400mA each and select the 1A 12V regulator.
With this controller you can run a 24V or 36V or 48V inverter with essentially no changes to the electronics. The Toroid and the choke are the only parts that need to be changed to suit the DC input voltage and Power output requirement. Of course the Nano low voltage shut down will need to be modified to suit the input used.
The FET Power board is galvanically isolated from the controller card high power circuitry as far as the isolated Gate power supplies and opto drives go. There is a ground connection and a VCap sample output on the connector to the controller so the controller knows the state of the Caps voltage during pre-charge.
The following mainly refers to 48V operation:
Due to the Galvanic isolation and that the Power PCB & FET drives are powered from the controller card has some neat advantages. You can Power the controller card from ~15-16V onwards. Meanwhile the FET power boards high current connectors can be powered from 0 to 50V. As the SPWM drive from the controller will be at 99% (maximum from software as AC feedback is too low to regulate) it will still produce a nice sine wave even from 0.5V supply to the main FETs. This makes fault finding and testing before applying full battery voltage very simple and pyro technic free.
Or the whole inverter is low voltage friendly so without changing they wiring, any voltage from 16V up will produce a nice clean sinewave albeit starting from about 80VAC for 16V in. Note the controller card has a Jumper (J11) for this type of testing and operation so it ignores the low voltage input that would normally keep it in shutdown until above the Vlow threshold.
Edited 2024-03-09 09:49 by wiseguy