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Power Meter Calibration and Comparison

I would try pluging in the RED again to see if it still works then verify voltage of the PSU at the plug. If the reading is off then open the PSU and measure the output where the wire connect to the PSU to rule out problem with the PSU.
 





Also while you have the PSU open check the continuity of the wire between PSU end with the pin or pins of the plug. If there is a problem with the plug to wire connection you should see it here.
 
The plastic base on the plug screws off from the metal connector, which you should be able to see if there is an intermittent connection there... and you can test the voltage of the PSU from there as well, which now that I think of it, would be better to do before opening up the PSU since there are AC line voltages in there and one zap from a cap in there could be very bad (even if its unplugged).
 
not to mention it will allow you to see if that's where the problem is, if the connections are shorted or whatnot.
 
Laser calibration tip #814:
When you're bored while waiting for your laser reading to stabilize, don't wipe stains off your shiny zero knob >:(
 
so give us an update, pseudo.. what's the output voltage of the psu?
 
Nor have I and I've tried MULTIPLE times. Not just to contact him about this but to make payment for a calculator he sold me.
 
Well, I heard from Pseudo today and he indicated to me that he has mailed the defective laser back to me for repair. I'm 99% certain that it's just a matter of a basic short in either the plug or the driver. I will check it out and report back my findings. I would like to note, that he sent it express and it was supposed to show up today but has as of yet to arrive.
 
Kenom said:
Well, I heard from Pseudo today and he indicated to me that he has mailed the defective laser back to me for repair.  I'm 99% certain that it's just a matter of a basic short in either the plug or the driver.  I will check it out and report back my findings.  I would like to note, that he sent it express and it was supposed to show up today but has as of yet to arrive.
Click to expand...


Why does this happen EVERY TIME we start to run a group wide, meter comparison test? :D :P ;)

Peace,
dave
 
OK apparently the potentiometer broke inside the compartment.  I don't have any clue how that could have happened since it was TIGHT inside there.  What was the value of the potentiometer?  I may have a smt replacement here.

To clarify exactly HOW it's broken, the top of the potentiometer has literally come off the base. Without the wiper to adjust along the resistive circle it's useless.
 
Wow, that's really strange. I've never even seen one of them come apart and I've soldered and removed some a few times (and they get pretty beat up) with no problems...

Anyway, I replied to your email as well. But it's 50ohm 3mm Murata PVG3A, but the value isn't critical. The peak current will remain the same (as long as the pot's minimum resistance isn't more than a few 0.1ohm) no matter the pot's value, but the minimum output value will change. Do you know what approximate current you were running? You could even just replace the resistors on there to set a fixed output. The two resistors on there are in series, with the pot in parallel with the 2210 resistor, so the pot doesn't technically need to be on there for it to work, it actually is probably putting out about 5-6mA without it (likely why there was no visible output).
 
Well, I have some 100hm potentiometers taht I could easily slap in it's place. They are from the groove drivers so they are teh exact same size. So I'll swap it out.

I've no clue what the output was current wise. I set it to output not current. And since I've yet to find a good way to measure current after everything is assembled, I didn't measure it. I will replace this 50 ohm with my 100 ohm and turn it all the way down, then tweak it again to the desired output. I hope I can solder in that teenie space without removing any of the other components.
 
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