AVR powered by a DC-DC module

This is the generator that failed one of its aux power supplies in the engine, which is responsible for supplying the AVR Power.
There’s a trick to fix this,
First measure the coil voltage from known good coil (this diesel yanmar gave AVR 30V-ish AC)
Then multiply the voltage by 1.414 and set the DC-DC board to the multiply result(30*1.414=42.42), then hook it up to AVR and 12v DC source (power on wire and ground) and done.
The typical AVR circuit has built in rectifier before actually using the power, so we can directly apply DC voltage to the AVR, but the voltage after rectifier will go 1.414 times higher than AC voltage we measured.
Not every AVR is going to work in the same way, so read your circuit diagram carefully before doing this yourself, I won’t pay any responsibility for any damage you guys have done.