| Converter Schematic | Master uC Schematic |
|---|---|
 |
|
The schematics for the converter and the master uC boards are separate files. Each schematic is intended for a separate board. For proper operation, one master uC is needed and up to four converter boards may be used.
You may also download our board layouts. This zip file contains the board layout for both the master uC as well as the converter boards. It was made using FreePCB v. 1.3.5.3
Known Errors
- The diode specified for D6 on the converter board schematic is too small. The diode will have a peak reverse voltage of 480 volts under normal operation. Use a diode rated for Vr of 600V or more.
- The trace impedance between the power mosfets (M1,M2) and the IR2110 driver chip is too low. A small series resistor (10 ohms) needs to be inserted into the trace to prevent the mosfet driver from damaging itself due to overcurrent.
- Resistors were accidentlly omitted from the keypad on the master uC board. Without a 1k resistor on each row, it is possible for a user to press two buttons and short out the master controller's power supply, resetting the entire Power Melder.
- The master uC uses a 3.3V line to drive the LCD. Our LCD requires 5V to work properly. The remedy to this situation was to move the power supply from the connector and connect it to the 5V microcontroller bootstrap supply. The contrast (0-3.3V) does not have to be changed.