T
treez
Guest
Hi,
Today I tried to measure the capacitance of a 100n ceramic cap on an unpowered PCB that had not been powered for several days. In service this capacitor has 339V pk on it.
I used a Tenma 72-8155 capacitance meter....
https://uk.farnell.com/tenma/72-8155/multimeter-lcr-83x172x38mm/dp/1283643
There was a “click” type sound as I probed the capacitor with the 72-8155 meter….which I guess was some excess charge on the capacitor discharging through the meter.
After this, the meter would not work.
I am surprised that the capacitance range doesn’t have overvoltage protection on it.
I wonder if anyone has a schematic of this meter?.... because maybe its just a crowbar circuit that has gone and blown a fuse.
Seriously, capacitors often have excess voltage left on them and its so easy to forget…so I’m amazed the meter was not protected against this.
Now neither the R, L or C aspect of the meter works..its totally dead.
How may i repair?
Today I tried to measure the capacitance of a 100n ceramic cap on an unpowered PCB that had not been powered for several days. In service this capacitor has 339V pk on it.
I used a Tenma 72-8155 capacitance meter....
https://uk.farnell.com/tenma/72-8155/multimeter-lcr-83x172x38mm/dp/1283643
There was a “click” type sound as I probed the capacitor with the 72-8155 meter….which I guess was some excess charge on the capacitor discharging through the meter.
After this, the meter would not work.
I am surprised that the capacitance range doesn’t have overvoltage protection on it.
I wonder if anyone has a schematic of this meter?.... because maybe its just a crowbar circuit that has gone and blown a fuse.
Seriously, capacitors often have excess voltage left on them and its so easy to forget…so I’m amazed the meter was not protected against this.
Now neither the R, L or C aspect of the meter works..its totally dead.
How may i repair?