All the solar garden lights I've seen to date used a single nickel cell, which mandates some form of oscillator/inverter which uses a flyback inductor to generate the 3.4V for a white LED.I'm playing around with some old garden solar lights, and 'think' I understand most of this circuit, but do not understand the purpose of D2. Could someone en'light'en me?
Thanks.
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+1 I haven't seen one in a long time, a decade at least.The discrete component variety are getting rare too ...
I found the wreckage of one built with discretes, on the footpath behind the flats.+1 I haven't seen one in a long time, a decade at least.
I-robot.The same could be said of any of us.
Thanks. As usual, makes sense once someone explains it!It prevents the small current flow from Bat+, thru the bias resistors, and thru D3, when Q1 is OFF.
Actually; in I-robot, the machines decided humans needed 'looking after' - it was Terminator machines decided the human race was surplus to requirements.I-robot.
Well, I was in a hurry and stated the obvious. But if that is ALL it is doing, then removing it would make little difference, just a small current leak. I suspect it does more than that, something about biasing Q2 when Q1 is conducting, but I couldn't quite figure that out. Take it out and see what happens!Thanks. As usual, makes sense once someone explains it!