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0-30V/10A Adjustable power supply - Index

These documents describe building a microprocessor controller power supply, capable of delivering 0-30V output at 10A.

Project Index




Top view of the inside. Most of the mechanics have been finished. Just behind the main transformer, you can see the bridge rectifier with 100nF caps across each diode. Left of the rectifier is the mains relay. The power-on switch on the frontpanel switches on the secondary transformer. It is up to the microprocessor to activate the mains relay to switch on power to the main transformer.



Closeup of the pass transistors, 4x TOP3055 mounted on the heatsink through a opening in the PCB. Clearly shown is the 34.000uF capacitor across the rectifier with a bleeder resistor in parallel. Just behind this capacitor, there was some space left for a smaller transformer. This transformer supplies the +12V, -12V and 5V rails for all the analog- and digital circuitry. These circuits will find a place on a eurocard size PCB that sits on top of the aluminum pillars surrounding the big capacitor. Between this capacitor and the frontplate, there is sufficient room for the LCD display and all the buttons and switches needed.



Parallel to the development of the firmware for the power supply, I wrote a small PC application that allows you to control the PSU from the PC. In addition to that, the PC program also allows to produce graphs and displays the settings you make on the PSU frontpanel in realtime.

Next - Part 1, Transformer modification

2006-2007 combotec.com - PA3CNJ