OpenBCM V1.07b12 (Linux)

Packet Radio Mailbox

SP7YDD

[OBCM_Elk]

 Login: GUEST





  
G8MNY  > TECH     11.05.23 08:41z 80 Lines 2800 Bytes #9 (0) @ WW
BID : 47164_GB7CIP
Read: GUEST
Subj: LED Lights
Path: SP7YDD<SR1BSZ<IW0QNL<IZ3LSV<ED1ZAC<GB7CIP
Sent: 230511/0832Z @:GB7CIP.#32.GBR.EURO #:47164 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To  : TECH@WW

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
          쿟urns읓|읓Turns
       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
cathodes.
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
                     /e
Photo  쳐컴22K컴)컴컴 PNP
Cell  __        __   \
---->        AA        읕1k>
---->      NICAD 
       읕컴컴컴컴컨컴컴컴컴

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
          쿟urns읓|읓Turns
       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
supply.



Why Don't U send an interesting bul?

73 de John G8MNY @ GB7CIP


Read previous mail | Read next mail


 01.06.2023 19:14:20zGo back Go up