Not too long ago, enthusiasts developing microprocessor-based projects needed access to an ultra-violet (UV) eraser. Unlike current technology devices that can be electrically erased in seconds without even removing them from circuit, older EPROM-based devices have to be exposed to ultra-violet light to erase their contents.

The Jaycar "UV Anti-bacterial Cleaner" kills germs on toothbrushes and shavers and with a small modification can also erase EPROMs.

With the advent of electrically erasable memories (EEPROMs), the requirement for a UV eraser has gone by the wayside and it is unlikely that most hobbyists will have one in their kit. However, if you need to modify or repair older equipment that uses EPROMS or want to dabble with any of the microcontrollers that use EPROM-based program memory (such as the PIC16C745/65), then an eraser is still a "must have" item.

Dedicated UV erasers are available but at around $300 or more, they would be considered too expensive by most experimenters. Even home-built units could prove expensive with tubes costing around $70. Of course, exposure to sunlight for a week or so may erase the chip but don’t hold your breath!

A cost-effective solution lies in the Jaycar GH1507 toothbrush holder ($24.95). In its intended use, the UV light from the fluorescent tube in this product kills germs in your toothbrushes and shavers. As luck would have it, the light spectrum used for germ eradication also works well for erasing EPROMs.