Posted by DerrickRe on February 21, 2002 at 23:16:10:
This is for people familiar with electronics and can Burn a Microchip 12C508A microcontroller.
For my rotating monitor I needed an easy way to auto degauss the monitor. So I wrote this PIC. All you need is the prorammed(burnt) PIC, 2 microswitches and a 10k resistor. Mount the switches to activate at the Horiz. and Vert. limits. N.O or N.C. switches can be used but both have to be the same. (See the degauss.asm file for more info)
Then you have to find the degauss relay in the monitor. It is connected to the degauss coil. There is a transistor that drives the relay. Connect the 10k resistor to the base of this transistor.
For power look for a TTL IC and patch across this for the needed 5V. If you have to ask how, then get out of the monitor (sorry). Wire the rest of the IC as per the degauss.asm file.
All info is in the degauss.asm file, which can be read with a text editor. The degauss.hex file is the HEX file needed for burning the IC.
Sorry I can't explain better. Maybe I'll post more when the cabinet is done. Just thought it might help someone.
And remember... the degauss circuit has a thermistor that heats up to reduce power to the degauss circuit. This slowly reduces the magnetic field for proper degaussing. The thermistor has to cool before you can degauss again. 1-2 minutes minimum is needed to allow the next degauss to be at full strength.