Aobao 2pcs High Voltage DC-DC Boost Converter 8V-32V to 45V-390V ZVS Step-up Booster Module Capacitor Charging Power Supply Module Adjustable Voltage Output

Meets voltage and current specs. Heat sink runs close to room temperature with output running at 200 v 5 ma. Output voltage seems to hunt plus our minus 1 volt with a constant load and some “noise” on output but still is an off the shelf inexpensive answer for many needs. Just keep in mind this is a Flyback inverter not a linear power supply and great for many projects.

I am able to get the high voltage to 400 needed for testing.

It's a decent high voltage supply for the cost. It's not a ZVS circuit, but is based on the UC3843A current mode PWM controller IC. It provides a reasonably stable output, though the peak to peak voltage can be a few volts when operating with low loads at high output voltage. The design seems to set the maximum switching current pretty high, which is fine, but results in the controller operating in pulse skip mode most of the time, so the unrectified secondary output can't really be used in a multiplier circuit. Overall pretty nice. Here is a composite shot of the controller with some annotations in case anyone else wants to tinker with the board.

This supply cannot be used on its own - unless you’re looking for a sawtooth output waveform. The designer did not properly incorporate an output filter. I supposed a CRCRC filter would work consisting of 2.2 uF, 450 volt film capacitors and 47k ohm, 5 watt resistors. Even then, you’ll still see some noise on the output.

tired to use these to charge my cars EV battery, these are greatly underpowered for that purpose. the first one let the magic smoke out within 10 seconds.

Needed 50V and ~400V for a project from a 24V source. I was able to get to 392.8V which worked perfectly. They hardly get warm, even with the one maxed out. Zero complaints. A great value.

The most I could get out of the units after buying four all at once, They all worked at 32 V DC with a maximum output of 366 V DC Be aware Did the negative side of the input is straight through to the output if you put these devices in parallel, you will need to use steering diodes to Prevent coupling of the positive outputs being fed back in to one another