... Now, by adding this green LED from negative to negative of 2 sets of batteries energy saving is even better than before and not less as we could expect having 2 LEDs instead of just 1. ...
Classic, The green LED was connected between a positive and a negative. If you follow the current around the loop, all is normal. Using "conventional" flow for simplicity, +5 from the somewhat depleted series string of four alkalines, thru the white LED which provides around 2 volts or so of Vdrop, connected to the positive terminal of the 4 somewhat depleted alkaline batteries in parallel provides another Vdrop of 1.2 volts. Open circuit voltage between the negative terminal of the parallel set of batteries and the negative terminal of the series string of batteries now at +1.8volts, which is the voltage applied across green LED when it is connected and the loop closed. LED Vdrop (actually referred to as Vforward) is current dependent so numbers given are approximate. The rather high internal resistance of the somewhat depleted batteries is what is limiting current (thankfully). PW
« Last Edit: 2023-11-01, 21:40:51 by picowatt »
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