cheap Chinese ebay LPMs vs Coherent LaserCheck vs LaserBee

[Giannis_TDM]

I didn't experience any thermal issues, no. Bear in mind it is only rated up to 1 watt though. Mostly I use it for the low-end stuff. I have two other power meters, one that tops out at 6.5 watts and one that goes to 15 watts, so most of the time the Lasercheck is seeing Class 3B stuff only.

But it's a solid device that is surprisingly accurate and consistent. Just make sure you clip that damned resistor off as soon as you get it. Otherwise you'll have a dead unit in about 3 years, even if it's been sitting on a shelf the entire time...

Adam

I think I have a good idea for you Adam so you can replace the battery safely, what if you get a supercap in the 10-20 F range and solder it across the bat, let it charge up to voltage and solder a new battery in. That way the board should be powered during the process causing no data loss.

 

[Buffo]

what if you get a supercap in the 10-20 F range and solder it across the bat, let it charge up to voltage and solder a new battery in. That way the board should be powered during the process causing no data loss.

I suppose that would also work, but it seems like a lot of extra work to source the capacitor.

I changed the battery in my Lasercheck shortly after I removed the bleed resistor. I had already owned it for about 2 years and wanted to swap out the battery before it died. To maintain power to the board I soldered two small-gauge wires (# 28, if I remember correctly) to the battery leads coming off the board. Then I connected those wires to my bench DC power supply and dialed in 3.5 volts, which basically put the battery on a float.

Once that was all hooked up I just clipped the battery leads off really close to the battery and yanked the old one out. (This left two long leads sticking up from the board.) Then I had to trim the leads on the new battery so they were short enough to sit adjacent to the ones sticking up from the board without passing through the board. Then I just soldered the new battery leads to the old ones that were still sticking up from the board. After I got the new battery installed I just clipped off the two wires to the bench power supply and closed up the case.

I did have to add a wrap or two of black electrical tape to hold the case closed though, because I broke one of the tabs when I took it apart. But it's been working just fine now for over a decade since I swapped the battery.

Adam