HPS 140 Trigger Mode

Instruments HPS140 Handheld Pocket Oscilloscope
1

Good Morning

First of all, the HPS140 is a great device! Small, handy, and accurate!

Now i have some questions the manual does not answer:

1: What is the exact difference between the two trigger modes RUN and NORMAL?

2: When I want to measure the Wrms@8 Ohm, for example a Guitar Amplifier, i have to choose
the impedance of the loudspeaker cabinet, and connect the probe between + and - of the loudspeaker?
So when the cabinet has 8 Ohms I have to choose Wrms@8Ohm and have to get a sine wave as amplifier input?

3: The maximum Voltage for the HPS140 is 100Vpp, so when the Probe is in x10 Mode, i THEORETICALLY can
measure 1000Vpp. I work with CNC-Machines, they work mostly with voltages between 24V to 380V. So
with the probe set to x10 the HPS140 can handle the voltage up to 380V?

Thanks for your answer, the HPS140 will not be the last Velleman Instrument i buy!

2

  1. RUN: Unit triggers always.
    NORMAL: Unit waits until triggerpoint is reached before it triggers and starts drawing a trace.

  2. Theoretically yes, however, to save your speakers and ears, a dummy load is used. This is usually an 8 ohm power resistor of the proper wattage.

  3. Careful: supplied probe is a 600VDC type. 400VAC exceeds probe limitations. We recommend a x100 probe with proper ratings.
    http://www.velleman.eu/products/view/?id=384430