HIMNL9
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- Joined
- May 26, 2009
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Anyway, it's cheap enough to just made a constant current driver, to keep around for test your leds ..... just use the old, good, abused LM317 circuit ..... with only a pair of modifications .....
Place only a small capacitor on the output, like, 100nF ceramic in parallel with 1uF tantalium, and in parallel to them, place a 100 ohm 1W resistor, so you're sure that the capacitors don't have any residual charge, when you connect your diode ..... also, between the output of the LM317 and the capacitors, place a 3,3 ohm or similar, 1W, resistor, for safety ..... and, ofcourse, no on-off switches, just a pushbutton, so you cannot forgot it turned on (you can also place a led with its resistor, on the output pin of the LM317, just as indicator)
You can power up this circuit from your bench PSU, from a battery pack, from a 12V wall adaptor, or just incorporate it in the box, whatever you want ..... and for the ones that want and find good spring contacts, other than the wires with the alligator clips, you can place on it also "spring contact" sockets (can be helpful for test new, long pins LDs)
After all, you don't need a long time driver, here, but just a safe way for check your LDs, so this type of circuit is a good solution, is safe, is cheap ..... and if someone want to spend some more money and hook on it two lcd meters modules, one as voltmeter and one as ampmeter, you also end with a tester that not just test your diodes, but also gives you VF and current .....
Place only a small capacitor on the output, like, 100nF ceramic in parallel with 1uF tantalium, and in parallel to them, place a 100 ohm 1W resistor, so you're sure that the capacitors don't have any residual charge, when you connect your diode ..... also, between the output of the LM317 and the capacitors, place a 3,3 ohm or similar, 1W, resistor, for safety ..... and, ofcourse, no on-off switches, just a pushbutton, so you cannot forgot it turned on (you can also place a led with its resistor, on the output pin of the LM317, just as indicator)
You can power up this circuit from your bench PSU, from a battery pack, from a 12V wall adaptor, or just incorporate it in the box, whatever you want ..... and for the ones that want and find good spring contacts, other than the wires with the alligator clips, you can place on it also "spring contact" sockets (can be helpful for test new, long pins LDs)
After all, you don't need a long time driver, here, but just a safe way for check your LDs, so this type of circuit is a good solution, is safe, is cheap ..... and if someone want to spend some more money and hook on it two lcd meters modules, one as voltmeter and one as ampmeter, you also end with a tester that not just test your diodes, but also gives you VF and current .....