Do I need a High Voltage Passive Probe?

Hi all,

I have a oscilloscope Lecroy Wave Ace 2014 (100MHz max input volt 400Vpk Cat I) with Lecroy PP016 probe (300MHz 10:1 10Mohm 12pF 600V(DC+pk.AC) Cat II rating)

The scope itself has the probe setting range from 1x to 1000x. So it should be able to view 5V - 5kV/div in the screen.

I wonder whether I could use my existing scope and probe on voltage after bridge rectifier where the Vpeak value is range 280 ~ 336V as shown in the diagram below without damaging my scope and probe?



Or do I need to get a probe that has 100:1 attenuation feature and with higher max input voltage rating? Or I need to upgrade to High Voltage Passive Probe?

a) MULTI-CONTACT 68.9838-120-23 Oscilloscope Probe, 300 MHz, High-Voltage Passive Probe, 1 kV, 100:1 (cheap cost)

b) TEKTRONIX P5122 Oscilloscope Probe, 200 MHz, High-Voltage Passive Probe, 1 kV, 100:1 (moderate cost)

c) LeCroy HVP120 Oscilloscope Probe 400MHz (expensive)

Thanks...Hope can get some advises..

Yes, you can use the scope settings. But be careful, rather very careful about the ground.

You are discussing a low frequency measurement, why do you worry about probe bandwidth?

If the voltage measured voltage actually doesn't exceed the probe voltage rating, it can be probed with a standard 10:1 probe. But as mentioned, it's only possible if the circuit under test is either grounded or perfectly isolated so that it allows grounding by the probe.

The usual tool for high voltage measurements is a 100:1 differential probe. Besides the relative expensive types offered by LeCroy, you can get third party probes with 20 MHz bandwidth, well suitable for most power electronics measurement problems.