Old overhead projector blowing bulbs, diode issue...

[rplydon]

So I have an old Elmo HP-355 overhead projector that just started blowing bulbs. The bulbs are of the 82v 360 watt variety. I am fairly certain that it is using some sort of diode to drop the voltage down from the rectified 110 line voltage to get the 82 volts. As I do not think that there is a replacement part for this anymore, what sort of diodes would I need to replace this part with modern components? Thank you very much.



https://www.dropbox.com/s/ja7345gb580vsox/IMAG2773.jpg

 

[duke37]

You can normally check a diode with a meter, they will either be open circuit or shorted. In your case a shorted diode will give too high a voltage

If it is a diode, which I am not sure, then a 400V 10Amp diode would do. It would need to be in the same configuration to fit to the heat sink. Is there a number on it?