Vulcan Power Supply
The power supply is one of the real core pieces of the lab. It needs to fulfill many purposes.
Goals
- V/A limiting output
- Multiple isolated outputs
- Wave Generator
- High power 3 phase output
- High power ESC
- Welder driver
Design
I think it will be computer controlled, with it's own dedicated computer (like a RasPi).
There are probably going to be about 8 outputs.
High Power
There will be 3 high power outputs with a common ground. These are used to drive a 3 phase motor. One of the outputs will be rated for welding.
Isolated Lab Outputs
These are much lower power but designed for current limited and much cleaner. I may make one of them analog regulated.
Stages
Input
Can take 220V, a single 110v or two 110v which it will check are 180° out of phase. Current limit can be set.
Rectification
Can be done with a diode rectifier though I think an active rectifier with an H bridge would actually be more efficient. Output is smoothed with a cap.
Oscillator
Converts the DC to a high frequency AC tuned to the powdered core.
Transformer
Using the oscillator allows us to use a cheaper powdered core transformer, possibly even a DIY version. There will be several secondary windings. Enough to compose a few into voltages within 20% of any desired voltage, plus a few extra to drive mosfets.
1.5 Bridge
To be able to output 3-phase, we need 3 half bridges. And because we'll be supporting a wide range of voltages, this get to be a lot of fun.
- Driver Logic: Takes a signal for what gates to turn on and off and makes sure the high and low side of one bridge are never both on. Each bridge can be in 3 states (high, low, off). So 9 total states rounds up to 16, so 4 bits of input.
- Charge Pump: When it's on, it produces Vcc+10v for driving the high side fets
- 10V: just need a 10V reg for the low side
- Opto-Isolators: these sit between the driver logic and the gate drivers. Because of the wide current range they each need a current regulator on the diode side.