DIY Eprom Eraser

[Hiwi]

Hi,
i had a traditinonal UV Eraser with a tube which was not working again, the tube was worn out. I use it for burning ROMS for my HP PortablePlus and for the CMT ROM Drawer for the HP71 and other hobby projects.

Looking for a replacement I saw prices from 200 bucks and much more.

I tried these cheap chinese eprom eraser, but they don't work reliable. I think the wavelength of the leds is too long.

Meanwhile I took a so called sun lamp from the 1950's with IR and UV quartz lamps.
This works good but produces too much heat and ozon. It is a kind of a hell machine and i have much respect :-)

There are on TAS some 100mA uv led with just 250nm of wavelength. Search for UV-C LED 0.1A.

I ordered two for litte money from china and gave them a try. And guess what?
I works perfect! Only 3 minutes and the eproms are empty!

I made a small cabinet with a switching integrated powersupply of 12 volts 3W and a constant current source with a simple LM317 delivering 100mA.

The eproms are mounted on the cover with a piece of foam rubber. During operation the cover is inserted into the cabinet.

The leds come mounted on a copper carrier with power terminals for soldering. I soldered them parallel on a piece of copper pcb for best heat dissipation, but this is not nescessary since there is only minor heat.

May be i add a 5 min timer with a CD4060 one day.

But I am happy like it is: