The circuit is an altered Joule Thief of my design that is driven by an AA or AAA battery. I’m observing the current at the battery anode with my DMM in series. (Extech EX330)
This circuit is extremely efficient (In relation to other Joule Thief I've build.) and does some weird stuff – like, it needs a pushbutton sometimes.
It is drawing 9.21 mA DC and 6.48 mA AC in series with the battery.
It shows 1.364 VDC and 0.010 VAC in parallel with the battery.
Output on the LED is 2.572 VDC and 0.011 VAC with no measurable frequency. (with my DMM at least)
All measurements are taken with the same configuration and voltage.
But how is it drawing AC and DC and how do I calculate power consumption?
–> Could it be because the emitter pin of the NPN is directly connected to ground?
–> Or is the circuit just "switching on and off"?
Download schematic: https://drive.google.com/drive/folders/1Vr9mQx449-RmjqclVZdgrnk5SyXjxTlG?usp=sharing
(I tried to simulate the circuit in LTspice. Thanks for making me aware of this amazing program, Sredni Vashtar!)
What the pushbutton is used for:
The pushbutton is used to "kickstart" the oscillation when it wont start by itself.
For example: I have to manually "oscillate" using this button to start the circuit if the capacitor is too big and battery voltage is low.
Pushing the button releases the energy in the transformer into the capacitor. If it reaches LED forward voltage the circuit keeps oscillating on it's own.
It does work without manual intervention when then capacitor in parallel with the LED is not too big, like <5000 µF, and it's a fresh battery.
Thank you for your answers! I'm learning so much! 😀