How reliable is the Power Profiler II?

RE: How reliable is the Power Profiler II?

mathiaso — Fri, 29 Sep 2023 06:39:23 GMT

I understand. Please give me an update when you have tried with the resistors.

And as mentioned in my last reply, could you try to perform the measurements using 100 kS/s (especially to identify what's happening in the lower, downward spikes)? There is a suspicion that wrong calculations after the last update may be caused by averaging. Using 100 S/s or 1 kS/s wouldn't give a high enough speed to discover if this is the problem.

RE: How reliable is the Power Profiler II?

mahboud — Thu, 28 Sep 2023 07:20:09 GMT

1. The reason I was measuring in series is because of the numbers I was seeing when measuring just using the PPK. I had to verify the numbers, and also to see if that strange pattern was visible on the Fluke - it wasn't and it spanned 10 seconds so it should have been easy to see it on the Fluke.
2. I am using AMP mode. I have tried sampling 1000 and 100 samples per second. I didn't see an improvement.
3. The voltage is typically between 4V and 4.2V. I am using Lithium Polymer batteries that is pretty fully charged. I have been testing dozens of boards. They each have their own battery. I unplug the battery and place a little harness between the battery and the boards. That harness allows me to route the power to the PPK's Vin and Vout, with a ground from the battery negative to the PPK's GND.
4. I was thinking that the issue could be with PWM, but a 10 second period is something else.
I'll try sampling with some resistors.

Keep in mind that I've been measuring currents on these devices for about a year now, and it seems like a lot of the problems I have with the PPK, cropped up after the last update (which I can not roll back).

RE: How reliable is the Power Profiler II?

mathiaso — Wed, 27 Sep 2023 08:00:19 GMT

Hi again, Mahboud!

Some suggestions and questions for further investigation:

Try to perform measurements separately, as placing measurement equipment in series tend to have undesired side effects.
What settings are you using?
- SMU or AMP mode?
- Sampling speed (may cause averaging, which again may give wrong calculations)?
- Voltage level of measurements?
What are you using as voltage source? And what is the voltage level of this?
What is the current measured in the lower spikes of the curve (use 100 kS/s when measuring this)?
Could you also try measuring a component that you're 100 % sure is static (e.g., a resistor)? As the ESP32 is an MCU, it might be running PWM or other things causing an unexpected pattern in the current consumption.

Best regards,
Mathias

RE: How reliable is the Power Profiler II?

mathiaso — Mon, 25 Sep 2023 18:13:29 GMT

Hi, Mahboud!

I'm looking into your case and will get back to you.

Best regards,
Mathias