Hi all,
I know it has nothing to do with audio, but it's electronics.
I have a solar yard lights acquisition syndrome.
Some of them are nearly 10 years old and still work, some are duff right out of the box (in typical chinese manner).
I have opened one and drawn a schematic
For the life of me, i can't figure out how it works!
I've checked the voltages: with the battery at a steady 1.32V, the Led anode is at 1.23V when lit, 1.32V when off.
I just don't get it. How can the LED be lit with 1.23V and off with 1.32?
I have drawn the schematic of an older discrete version - non-working so I couldn't take measurements, but I suspect it's the same basic circuit in the chip.
This second circuit, I could understand that the shunt transistor would turn of the LED by deriving current to ground, but that seems to me a waste of energy.
I've tried to google the subject, to no avail.
Anyone has an idea on this?
Thanks all.
ARdE
I know it has nothing to do with audio, but it's electronics.
I have a solar yard lights acquisition syndrome.
Some of them are nearly 10 years old and still work, some are duff right out of the box (in typical chinese manner).
I have opened one and drawn a schematic
For the life of me, i can't figure out how it works!
I've checked the voltages: with the battery at a steady 1.32V, the Led anode is at 1.23V when lit, 1.32V when off.
I just don't get it. How can the LED be lit with 1.23V and off with 1.32?
I have drawn the schematic of an older discrete version - non-working so I couldn't take measurements, but I suspect it's the same basic circuit in the chip.
This second circuit, I could understand that the shunt transistor would turn of the LED by deriving current to ground, but that seems to me a waste of energy.
I've tried to google the subject, to no avail.
Anyone has an idea on this?
Thanks all.
ARdE