Hello, I'm new to this website, seems like a pretty great resource.
I'm having some problems with getting my project to work. I am familiar with electronics.
I'm trying to drive two high power LEDs (3W each, 3.6v (4vmax) forward @1000mA) with an LM338 chip. the input voltage varies from about 6-9VDC.
using the data sheet for the LM338 I used a 120ohm for R1 (between Vout and Adj) and a 330ohm for R2 (adj to ground)
this should give me about 5volts right?
I dont have much for equipment, but the voltage seems inconsistent. and when I put it in use, it only takes a couple minutes for the LEDs with 1ohm 10W resistors in series with them to either blow or get so hot they desolder themselves.
I bought these on ebay for cheap. could they be fakes? does my simple design make sense? thanks!
I'm having some problems with getting my project to work. I am familiar with electronics.
I'm trying to drive two high power LEDs (3W each, 3.6v (4vmax) forward @1000mA) with an LM338 chip. the input voltage varies from about 6-9VDC.
using the data sheet for the LM338 I used a 120ohm for R1 (between Vout and Adj) and a 330ohm for R2 (adj to ground)
this should give me about 5volts right?
I dont have much for equipment, but the voltage seems inconsistent. and when I put it in use, it only takes a couple minutes for the LEDs with 1ohm 10W resistors in series with them to either blow or get so hot they desolder themselves.
I bought these on ebay for cheap. could they be fakes? does my simple design make sense? thanks!