Today I would check a battery using the HPS140 but the voltage readout just flickered and did not show a stable DC value. It was done just after power on. Then I connected the probe to the test signal and also here the signal just rolled down the screen without a proper trigger. I have tried power off / on several times. I can’t see any of the settings is wrong and it is my impression that after power on you can just measure the test signal and a stable square wave shall be shown?
Any ideas of what can be wrong? …a “burnt” input circuit?
I just tried to connect the USB power cable to the HPS140 and charge the battery via my PC and with the power cable connected to the unit the trigger problem has gone. So my theory is now that the unit was low on battery power and this caused the trigger problem. I will see when it has recharged for some hours.
I wonder if a PC is the only source for recharging the unit? …or could I use one of the adapters with USB connector you plug into the main supply (5V DC output)?
If the problem is the above it could be nice with a “battery low” indicator and also a “full charged” indicator would be nice?
You can use a mains to USB adaptor or a 9V DC adaptor with the correct plug.
Unit will be fully charged after approx 6h.
Due to the low-cost nature of the unit, it is not equipped with a ‘battery low’-indication.
When the battery is fully charged, the ‘charge’-led will burn less bright.
Ok…thank you for the answer. I used a USB adapter to fully recharge the battery and now everything works as expected.
I have used the HPS140i to measure voltage above 100V with the probe set to x10. That was my interpretation that the 100V max. voltage is at the BNC connector and if you set the probe to x10 you can measure higher voltages than 100V? …as least it worked for me…but I was afraid that it was a wrong interpretation and this has caused a burnt input circuit.
Can you measure up to 1000V pp if the probe is set to x10?