I think this, or something very like it is still available--look in the diode section of the mouser and digikey catalogs--I know I bought a variety a year or so ago. Not real precise--3-5%, but available in current ranges from 1 or 2 ma up. however, NOT cheap. Kelly At 02:56 AM 12/2/99 -0800, you wrote: >You can make a current limiter out of an LM317 with a resistor across >the "Output" and "Reference" terminals, if they just packaged such a die >with the resistor as a 2-terminal package, that sounds about like what >you have there. Nice discrete, it makes GOOD sense to use those for >LED's, wish I had some here! Great for a number of applications. >Car tail light LED units, for one. > >Related question; Wonder what happens when one parallels these >devices? I'd think the "conductances" would add, 2 paralleled 20mA >units should let about 40mA flow, but I haven't tested it yet. Should >get to that some day > > Mark > >Don Holtz wrote: >> >> Hello: >> >> I was recently in Japan, and visited Akihabara. While there I picked up a >> handful of really bright White LEDs. With each LED the vendor also gave me >> an interesting discrete device that looks like a standard small-signal >> glass encapsulated diode. >> >> I don't speak Japanese but I was able to get the vendor to draw a simple >> schematic, since I was confused about the device. >> >> The device appears to be a "current regulating diode" analogous to a >> zener.... 15mA! >> >> In this instance the LED and "current regulating diode" are placed in >> series, and the combination can be driven with a voltage between 4V and 20V. >> >> Further testing shows that below the "turn on" current level the device has >> a fairly low impedance (approx. 200ohm), above the "turn on" current level >> the device has a fairly high impedance of more than 100Kohm. >> >> The only marking on the device is E153. >> >> The symbol the vendor used in the schematic was a circle with a bar, kind >> of like an arrow head with a bar (for a diode). >> >> What is this device? Am I missing something simple? >> >> Cheers, >> Don > >-- >I ship small packages for small businesses, world-wide. >(And for private individuals at cost, just ask.) > > William K. Borsum, P.E. -- OEM Dataloggers and Instrumentation Systems & San Diego, California, USA