This new circuit uses a darlington pair of bc547 Low Noise Transistors 50V at 100mA. I am measuring the voltage across a 1 ohm resistor in the ground loop between the battery and the circuit ground. I am using a variable capacitor 50-150pF as well as a 500K ohm variable resistor. The toroid is wound approx 15 turns triple wired the extra winding provides the green led. The Green trace measures the input power. The Yellow trace measure the output voltage across the green led.
This circuit operates at 208kHz and is consuming on average 15-20 milliwatts. The output waveform is approximately 10V peak-to-peak. I am currently constructing a diode bridge to measure the output power.
It turns out that i was measuring the input power incorrectly.
I tried using two similar 1.7 ohm resistors and connected the diode bridge.
The yellow trace represents the output power. Green is the input power.
I must say this looks like an overunity.
There is a potiential problem with the probe capacitance this could be causing incorrect measurements.
ReplyDeletehi Georgie, interesting site! i'm also a 'softie' who dabbles with h/w (i'm the 'Doc' mentioned in your August post)
ReplyDeletea useful alternative way to measure electrical input energy (on small systems) is to power the circuit from a fairly large capacitor and measure the discharge energy
you need to know the capacitance more accurately than just using the label value (which is usually only +/- 25% say), but this can be done easily using a measured resistor, a DVM and a stopwatch
i was also interested in your 'copper steel battery' - you use cotton wool (and presumably get more volume for your 'electrolyte', as a result)
i use squares of cotton cut from linen serviettes (& hope nobody questions the holes at dinnertime) because i want to get the copper & zinc plates close together - also i think the honey i use is more of a dielectric than electrolyte, and i believe that this significantly reduces the corrosion of the electrodes (but provides less current?)
you could try replacing the steel plate with aluminium baking foil (NB. see dinnertime comment above) - this may give you increased o/p
hope this helps - keep up the good work!
doc_r