david90
Advanced Member level 1
I'm trying to troubleshoot my FLUKE 1520 MEGGER. All functions work except for the high voltage 250/500/100V megger test. When I pressed the test button, I get no voltage on the output even though the display indicated that the unit is trying to output something.
I opened up the unit and I could see that it uses the IC ucc2805 as the dc-dc controller. I probed the drain of the mosfet that is connected to an inductor and I don't see any switching. I then probed ucc2805's output pin and I see this
peak voltage = .5V-.7V.
**broken link removed**
I apologized for the low quality scope capture above. I think the scope needs calibration ;P.
Could somebody tell me what the output means and why it's shaped like that? I'm hoping somebody with more experience can point me in the right direction
I opened up the unit and I could see that it uses the IC ucc2805 as the dc-dc controller. I probed the drain of the mosfet that is connected to an inductor and I don't see any switching. I then probed ucc2805's output pin and I see this
peak voltage = .5V-.7V.
**broken link removed**
I apologized for the low quality scope capture above. I think the scope needs calibration ;P.
Could somebody tell me what the output means and why it's shaped like that? I'm hoping somebody with more experience can point me in the right direction