WTF, is the Batteriser output voltage really this bad? 1.85V output peak?
This explains why all the 1.5 V incandescent light bulbs Ysjoelfir tested were destroyed after some time. I guess these small light bulbs can follow the peaks very good, because they are so small and not slow like bigger lamps. Might reduce life time of the cheaper LED lamps with no regulation as well.
... and at around 11KHz for those transients, there's potential for other problems.
... and at around 11KHz for those transients, there's potential for other problems.
I don't get that either. Why would you switch at 11KHz with such small magnetics?
The weird...ripple, for lack of a better word...that you are measuring must be some larger-scale artifact of the control circuit.
The weird...ripple, for lack of a better word...that you are measuring must be some larger-scale artifact of the control circuit.That makes sense - as an explanation for the observed waveform ... but you have to wonder about it as an artefact of the design... especially as a design that has been implemented in the final product.
WTF, is the Batteriser output voltage really this bad? 1.85V output peak?
... and at around 11KHz for those transients, there's potential for other problems.I don't get that either. Why would you switch at 11KHz with such small magnetics?I believe earlier in the thread some other person zoomed in really close on the ripple and found that the switching frequency was something like 1.2MHz or 2.5MHz. The weird...ripple, for lack of a better word...that you are measuring must be some larger-scale artifact of the control circuit.
In the linked review:
... and at around 11KHz for those transients, there's potential for other problems.
I don't get that either. Why would you switch at 11KHz with such small magnetics?
I have no idea what is causing the 1.8V+ peaks before the Boost mode goes to sleep. Perhaps the chip design has a few design problems? Or do they deliberately force the output to 1.9V before sleep?
It just occurred to me: Did HKJ check the input voltage to the batterizer (from the Lab Supply / Cap)? Possibly the input already has stability issues, so the jump from 1.6V (1.4 + 0.2 boost amount) to 1.8V is not caused by the batteroo boost sleeve, but by the benchtop PSU supplying it.
It just occurred to me: Did HKJ check the input voltage to the batterizer (from the Lab Supply / Cap)? Possibly the input already has stability issues, so the jump from 1.6V (1.4 + 0.2 boost amount) to 1.8V is not caused by the batteroo boost sleeve, but by the benchtop PSU supplying it.
No, I did expect the Keithley 2460 to have it fairly well under control with a 4 terminal connection.
The weird...ripple, for lack of a better word...that you are measuring must be some larger-scale artifact of the control circuit.That makes sense - as an explanation for the observed waveform ... but you have to wonder about it as an artefact of the design... especially as a design that has been implemented in the final product.
Just because I said it was an artifact of the design doesn't mean I meant it was a intentional or desirable part of the design.
I think Dave nailed it with something causing the control loop to oscillate. It's too irregular to be anything intentional.
My review of the batteroo is up: http://lygte-info.dk/review/batteries2012/Batteroo%20AA%20UK.html
Awesome work
WTF, is the Batteriser output voltage really this bad? 1.85V output peak?
I can confirm similar but not as bad behavior with a 1.4V input, 150ohm load (resistor box), and a Rigol DP832 PSU input.
That does NOT explain the original, blue waveform. It is much too distorted to be an intentional kind of burst mode. Given that the output voltage is horribly distorted with the low input resistance, and perfect with an actual battery, it must be some kind of instability in the control loop.
Setup is as follows:
PSUA (Supply), HP 6632B, CV mode supplying the Batteriser input voltage
PSUB (Load), HP 6632B, CC mode loading/sinking the Batteriser output fixed at 125mA
That does NOT explain the original, blue waveform. It is much too distorted to be an intentional kind of burst mode. Given that the output voltage is horribly distorted with the low input resistance, and perfect with an actual battery, it must be some kind of instability in the control loop.
I am getting more and more suspicious about my power supply, maybe it did not deliver as stable voltage is I expected. I hope to look at it later and if necessary update the curves.
Anyway the curves with the alkaline do not have any instability from any power supply.
A simple fix would be to add a big electrolytic cap across the power supply output.
I'd hope that a PSU already has a big electrolytic cap across its output.