pete_pumpkin
New Member
Reading a few recent threads I've come across some people trying to wipe their EPROMs out in the sunlight - well no need to suffer any more 
For around $20 you can have your self a UV EPROM eraser. The procedure and initial idea comes from Silicon Chip magazine march 2005.
http://www1.jaycar.com.au/
What you need is a 'toothbrush sterilizer' which is available from Jaycar electronics for $19.95 Jaycar CAT GH1507 This unit normaly sits up on your bathroom wall and holds a numberof toothbrushes and a razor. It's run by six AA bateries. What happens is when you stick your toothbrush in and close the door, the UV lighs switches on and does it stuff for around 3 minutes. After that the internal 'RC' timming circuit switches the unit off.
3 minutes isn't really enough for the UV light to do its stuff on an EPROM. So you need to alter the timming circuit so that the combination of components, (typically consisting of a resistor and a capacitor) will increase the time the light is on to about 20 minutes (recommended in SC mag).
So what you do is increase the capacitance by sticking another one in parallel with the appropriate one which is allready there (220uF). Below are some photos showing where you need to solder the other capacitor. SC mag recommends a 1000uF electrolytic capacitor with a 25V rating. My built unit gave me 14minutes and 50 seconds. SC magazine says 15-20 minutes should be the result. Eitherway I think 15 minutes should be OK to wipe an EPROM?
You need to solder it in parallel so neg to neg pos to pos etc. You can solder your wire directly to the pad or as seen in the pictures below you can use a sharp knife to scrape some of the laquer off at the same electrical point. You can use flux and pre-tin your wires and pads etc to make the job easier.
In the magazine it shows a novel way of mounting the EPROMs. As I only just bought the unit a few days ago, I still haven't fabricated anything. You basicaly can use a couple of dowels in place of two toothbrushes with a strip of cardboard, plastic or watever attached to the dowels. On the plastic or cardboard you can glue a peice of antistatic foam which will hold the EPROMs in place.
And that's it I guess. I just need to get my self a burner now. BTW I found a good source of eproms - old PC motherboards and video cards. Their mainly 27c256 or higher.
Good Luck fellas, if you have any questions don't hesitate to ask, as you can see though it's pretty easy.
For around $20 you can have your self a UV EPROM eraser. The procedure and initial idea comes from Silicon Chip magazine march 2005.http://www1.jaycar.com.au/
What you need is a 'toothbrush sterilizer' which is available from Jaycar electronics for $19.95 Jaycar CAT GH1507 This unit normaly sits up on your bathroom wall and holds a numberof toothbrushes and a razor. It's run by six AA bateries. What happens is when you stick your toothbrush in and close the door, the UV lighs switches on and does it stuff for around 3 minutes. After that the internal 'RC' timming circuit switches the unit off.
3 minutes isn't really enough for the UV light to do its stuff on an EPROM. So you need to alter the timming circuit so that the combination of components, (typically consisting of a resistor and a capacitor) will increase the time the light is on to about 20 minutes (recommended in SC mag).
So what you do is increase the capacitance by sticking another one in parallel with the appropriate one which is allready there (220uF). Below are some photos showing where you need to solder the other capacitor. SC mag recommends a 1000uF electrolytic capacitor with a 25V rating. My built unit gave me 14minutes and 50 seconds. SC magazine says 15-20 minutes should be the result. Eitherway I think 15 minutes should be OK to wipe an EPROM?
You need to solder it in parallel so neg to neg pos to pos etc. You can solder your wire directly to the pad or as seen in the pictures below you can use a sharp knife to scrape some of the laquer off at the same electrical point. You can use flux and pre-tin your wires and pads etc to make the job easier.
In the magazine it shows a novel way of mounting the EPROMs. As I only just bought the unit a few days ago, I still haven't fabricated anything. You basicaly can use a couple of dowels in place of two toothbrushes with a strip of cardboard, plastic or watever attached to the dowels. On the plastic or cardboard you can glue a peice of antistatic foam which will hold the EPROMs in place.
And that's it I guess. I just need to get my self a burner now. BTW I found a good source of eproms - old PC motherboards and video cards. Their mainly 27c256 or higher.
Good Luck fellas, if you have any questions don't hesitate to ask, as you can see though it's pretty easy.
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