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I saw it mentioned in another thread that you don't need a test load made of diodes and whatnot to test driver output. One of the people in the thread said that he just used a high-wattage resistor as the test load and claimed that he never had a problem with it.
The logic put forth was that the laser diode drops 100% of the voltage put to it, and that the driver is going to apply whatever voltage it needs to in order to deliver its set current through the load. With that in mind, a high-wattage resistance that will keep the driver within its safe voltage limits should function as a test load.
Can I then put the DMM in series with the circuit for a direct current measurement? Or will it introduce oscillations and/or otherwise give a bad reading?
Curious about it; I have a dead 650nm diode here from a Lazerer LZCS, looks like an LPC-826 or similar. The driver seems ok, it will light up the LED'd diode. I'm guessing it's some kind of buck driver, or maybe a linear... it has a transistor and an IC, a resistor, some caps. No coil. Would like to see what current it's set to and whether I could use it for something else. If I put 8.2 ohms across it the driver should be fine because unless it's a boost driver (red diode, so it's not) then max v-out 3.7 volts, which would be at most 451mA with an 8.2 ohm load. Right?
I just wanted to find out ahead of time if I can use a power resistor and be fine with that, or if I do need to put together a test load with diodes and the like. I would hate to try it later, on a driver that I do care about, and have it die. Thanks for any clarification on the matter!
The logic put forth was that the laser diode drops 100% of the voltage put to it, and that the driver is going to apply whatever voltage it needs to in order to deliver its set current through the load. With that in mind, a high-wattage resistance that will keep the driver within its safe voltage limits should function as a test load.
Can I then put the DMM in series with the circuit for a direct current measurement? Or will it introduce oscillations and/or otherwise give a bad reading?
Curious about it; I have a dead 650nm diode here from a Lazerer LZCS, looks like an LPC-826 or similar. The driver seems ok, it will light up the LED'd diode. I'm guessing it's some kind of buck driver, or maybe a linear... it has a transistor and an IC, a resistor, some caps. No coil. Would like to see what current it's set to and whether I could use it for something else. If I put 8.2 ohms across it the driver should be fine because unless it's a boost driver (red diode, so it's not) then max v-out 3.7 volts, which would be at most 451mA with an 8.2 ohm load. Right?
I just wanted to find out ahead of time if I can use a power resistor and be fine with that, or if I do need to put together a test load with diodes and the like. I would hate to try it later, on a driver that I do care about, and have it die. Thanks for any clarification on the matter!
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