HPS140 for car audio

Instruments HPS140 Handheld Pocket Oscilloscope
1

Hello,
I recently just purchased a HPS140 pocket scope to fine tune my car amplifiers, this is my first time using an oscilloscope so I had a couple questions…

I am going to be testing two amplifiers for clipping.
Amplifier A will be seeing voltages from 10-15 volts.
Amplifier B will be seeing voltages from 40-60 volts.

Should I be using the x1 probe setting for Amplifier A and x10 probe setting for amplifier B?

Also from what I am reading, once I change the probe setting to x10 all I would then need to do is go to settings and select x10? Once that is done am I good to go or is there anything else that I would need to do before I can test for clipping on the car amplifiers?

Thanks in advance.

2

Hey,
After some more reading up on oscilloscopes I think I should be able to use the x1 probe for both Amp A and Amp B.

Are my calculations correct?

If the max input voltage for x1 is 100vp then

100/(sqrt(2))=70.71 volts

Again, since x1 can handle up to 70.71 volts can I use x1 probe setting for both Amplifiers A and B?

3

x1 should be fine, however, it is always best to start at x10 when measuring unknown signals.
The scope is equipped with a ‘x10’ setting, so readouts stay correct.

4

Up to what AC Voltage can the x1 probe handle?
Is it 70 Volts AC, I know max is 100vp?

And is the x1 probe more sensitive than x10, what advantage do you have using x1 over the x10 at lower voltages?

I think to go from Volts AC you just multiple that value by 1.414 to get Volts Peak (vp) correct?

5

Scope can handle 100Vp at the input.
Probe can handle 600V at any range.
100Vp equals about 70Vrms for a sine wave.
Using ‘x1’ if possible results in higher resolution at low voltages.