OpenBCM V1.06 (Linux)

Packet Radio Mailbox


[C.D.G. OpenBCM]

 Login: GUEST

G8MNY  > TECH     18.01.19 11:00l 59 Lines 2451 Bytes #10 (0) @ WW
BID : 55113_GB7CIP
Subj: Thermostatic Soldering Iron LED
Sent: 190118/0952Z @:GB7CIP.#32.GBR.EURO #:55113 [Caterham Surrey GBR]

>From Fri Jan 18 10:53:12 2019
Received: from by (JNOS2.0k.3b) with SMTP
	id AA75380 ; Fri, 18 Jan 2019 10:53:12 +0100
Message-Id: <55113_GB7CIP@gb7cip.bbs>
>From: g8mny@gb7cip.#32.gbr.euro
X-JNOS-User-Port: Telnet   (gb7cip @  -> Sending message


By G8MNY                                 (Updated Mar 11)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)

This circuit is suitable "Magnetic Curie Point" temperature switch controlled
mains irons! The LED lights up when the Iron is plugged in & is drawing current
in its heat cycle it goes out when it is up to temperature. It also works on
some internally electronic controlled 24V irons too.

Also shown is a static earth, that keeps the stray tip voltage down to about
12V AC MAX, while still giving an "un earthed iron" for work on live circuits
(~100V) safely.

  Fuse   ON
LÄo-oÄÄÄÄo\oÄÄÄÄÄÄÄÄ¿                        Temp
       LED           )||(     10k           Switch        Curie   ³
     ÚÄ´<ÃÄ¿     230V)||(24V ÚÄ´               :...Magnet Iron   12R Element
     ³     ³         )||(    ³10k                         Bit    48W
NÄÄÄÄ´     ÃÄÄÄÄÄÄÄÄÙ ³      ³-----------------------------iron earth
     ÀÄ33RÄÙ          ³     1M          If 3 wire
The LED is connected to the mains neutral, but even so good insulation is
needed! The bypass diode connected the reverse way is a 1N4001 & stop mains
reverse voltage appearing across the LED. The value of 33R is selected so that
the LED is not lite with just the transformer magnetising current.

If the 50Hz flashing LED is anoying, blows up the LED, or is not bright enough
try this more complex circuit instead...

  ³    ³100u+³    ³      Here the 27R is selected for brightness & unlit LED
ÄÄ´    ÃÄÄ´ÃÄ´    ÃÄÄ    when the iron is not on. The 100uF protects the LED
  ô>ÃÄ)ÄÄÄÄÄÙ    ³      from some of spikes in mains power surges as well as
  ³    ÀÄÄÄÄÄÄ´>ÃÄ´      reducing the 100Hz LED flicker. Diodes are all 1N4001.

Also see my Tech Bul on "Soldering Iron Economiser/Boost"

Why Don't U send an interesting bul?

73 De John, G8MNY @ GB7CIP

Read previous mail | Read next mail

 18.01.2019 19:38:38lGo Back Go up