Diode help... HELP!

Bill: You should test your diodes with an OHM Meter that has a high enough test voltage to overcome the barrier potential of approx 700mV for a silicon, and about 300mV for a germanium device. What sort of application are you looking use it for? For high current/voltage applications, silicon is pretty much your only choice, as they can be made with very high PRV (peak reverse voltage), and higher power rating. For small-signal use, germanium diodes work best; they have low barrier potential and lower 'ON' resistance (sounds like this is what you want). Used to be, the glass diodes RS used to sell were a mixture of both types. You can tell the difference with a DMM that has a 'diode' test range; the DMM will put enough voltage across the device to foreward bias it (turn it 'on') and display the apparent resistance of the device. Germanuim devices will have a lower apparent resistance. Another way would be to apply a (low) voltage across the device with a resistor in series, and measure the voltage across the device. Of course, all diodes have some reverse leakage current, and all diodes exhibit this 'barrier potential' phenomena; the trick is to find one with a low enough 'on' resistance that will satisfy your requirements. I used to get diodes from RS to make crystal sets; in those days, I found the best ones by wiring it into the set to test it! Jeff On Tue, 22 Feb 2000 16:06:49 -0500 "Bill Sudbrink" <bill(a)chipware.com> writes: ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj.