K
Kevin McMurtrie
Binary posted to alt.binaries.schematics.electronic,
Message-ID <[email protected]>
I got bored and started playing with low voltage switch power supplies
again. This one has better regulation and a higher switching frequency
than the schematic I posted a long time ago. It can run with smaller L
and C values to reduce the circuit size. Really high frequencies
require more current to the complementary pair, so reduce the value of
the 100 Ohm resistor.
For a while or blue LED:
LED drive current: ~7mA equivalent
Threshold voltage: .8V
Full intensity voltage: 1V
Maximum voltage: 5V
Extinguishing voltage: .4V
0.047F cap @ 5V:
Dimmed at 19 seconds discharge.
Extinguished at 25 seconds discharge.
Transistors: General purpose TO-92.
I don't have a blinker for it yet. I'm not sure where to interrupt the
power so that it can restart quickly. The circuit takes some time to
bootstrap its power. Maybe the power could be interrupted at the top of
the complementary pair, if that doesn't loose too much power. A few
volts for the blinker can be recitfied from the inductor.
Message-ID <[email protected]>
I got bored and started playing with low voltage switch power supplies
again. This one has better regulation and a higher switching frequency
than the schematic I posted a long time ago. It can run with smaller L
and C values to reduce the circuit size. Really high frequencies
require more current to the complementary pair, so reduce the value of
the 100 Ohm resistor.
For a while or blue LED:
LED drive current: ~7mA equivalent
Threshold voltage: .8V
Full intensity voltage: 1V
Maximum voltage: 5V
Extinguishing voltage: .4V
0.047F cap @ 5V:
Dimmed at 19 seconds discharge.
Extinguished at 25 seconds discharge.
Transistors: General purpose TO-92.
I don't have a blinker for it yet. I'm not sure where to interrupt the
power so that it can restart quickly. The circuit takes some time to
bootstrap its power. Maybe the power could be interrupted at the top of
the complementary pair, if that doesn't loose too much power. A few
volts for the blinker can be recitfied from the inductor.
