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G8MNY  > TECH     11.05.23 08:41z 80 Lines 2800 Bytes #9 (0) @ WW
BID : 47164_GB7CIP
Subj: LED Lights
Sent: 230511/0832Z @:GB7CIP.#32.GBR.EURO #:47164 [Caterham Surrey GBR]

From Henner DC0OS @ DB0UHI.#NDS.DEU.EU      (Updated Jul 12)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)

LED at 0.6-1.5V

 旼컴컴컫컴컴컴컴컴컴컴쩡컴컴훟 +
          旼컴컴커           0.6- 1.5V
      1K        憫|憫
              3 | 10
       쳐컴         쳐컴컴훟
                  /      __  WHITE
===    ===         읕 NPN  _\_/_ LED
 100   100         \e      
  nF    nF                 
 읕컴컴컨컴컴컴컴컴컴컴좔컴컴훟 -

It works down to 0.7V.
The LEDs (colours don't mix) may have an alternate connection to +ve with the
The current is dependant on the bias resistor, not from the number of the LED
(tested with 1 & 3). 1 kilo-Ohm let flow 30 mA. More light will give a low ohm
transistor, but not much.
The transformer was built from a choke coil with a ferrite core like dumb-bells
(thats was my Dictionary says |-| ). The 40 turns for the collector filled it
half, the other half was for the basis-turns, the wire was thinner.

The fly-back generator is not optimized, you can experiment with core, turns &
thickness of wire, or use a better transistor with more gain & more current.
Also with the resistor & capacitor. I found the items in a box down in the dark
of my work-bench. I replaced 2 of 3 cells of my lantern, & now it can swim,
I dont have to dive to the ground to get back when it fall out of the boat...

73 from Henner, dc0os
White LEDs are about 3V hence the voltage step up circuit needed from 1 or 2
nicad cells. But you would not want to put one on top of a pole holding up HF
Rx ant due to the possable small level QRM!

For automated garden lights..

       旼캑>쳐컴컴쩡컴컴컫컴> +1.2V
Photo  쳐컴22K컴)컴컴 PNP
Cell  __        __   \
---->        AA        읕1k>
---->      NICAD 

The photocell is quite conductive in no light & turns on the PNP, this allows
bias current flow to start up the inverter.
LED at 11-14V

 旼컴컴컫컴컴컴컴컴컴컴쩡컴컴컫훟 +
               White__      +11-14V
                LED_\_/_   __
          旼컴컴커        /_\
      1M        憫|憫      1N4148
              1 | 10    or schotky
       쳐컴         쳐컴컴켸
===    ===         읕 NPN
 100    10         \e
  nF    nF           
 읕컴컴컨컴컴컴컴컴컴컴좔컴컴컴훟 -

In this circuit 2-3 times the current flows in the LED than is taken from the

Why Don't U send an interesting bul?

73 de John G8MNY @ GB7CIP

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