Joule Thief: Variation on Gadgetmall’s Low Current Circuit
By the time I processed this video, and halfway thru this upload, the battery voltage has climbed to 1.32 volts and the LED is moderately bright, somewhere between 7200 Hz and 8200 Hz with a very short duty cycle. So I made another short video showing the increased battery voltage, which I will upload in a few minutes. And…. Just glanced over my shoulder….. yep, 1.33 volts. So it’s still climbing. This is an alkaline AAA that is fairly fresh but was heavily discharged to about 1.2 volts earlier today, and has spent some time under enough load to draw it down to 0.84 volts while testing this circuit. Before I started this video its open circuit voltage was about 1.24 volts, IIRC. Note: At about 16:30 I try to calculate the current represented by the tiny narrow spike and I misplaced the decimal again. Using the numbers I mumbled, it is actually 200 mA in the spike, so assuming a one percent duty cycle that’s 2 mA average, which still seems high to me. It’s too bad I don’t believe in free energy, though. Voltage is not energy after all, and we all know how to “fluffy charge” a battery, and alkalines do recover some voltage after heavy discharge, and the voltage under light load isn’t a good indicator of charge level, and so on and so forth. Party pooper. (By the time I’m done editing and uploading this, the battery voltage has climbed to 1.34 volts.)
