Light bulb for WELLER Soldering Gun Model 8200?

Discussion in 'General Electronics Chat' started by sdowney717, Mar 18, 2015.

  1. sdowney717

    Thread Starter Member

    Jul 18, 2012
    386
    13
    Last edited: Mar 18, 2015
  2. wayneh

    Expert

    Sep 9, 2010
    12,127
    3,049
    Make sure your tip is good. The bulb is across the poles and will burn out if the tip fails open.

    The bulb resembles an automotive dome light, but I doubt it would be that easy.
     
  3. sdowney717

    Thread Starter Member

    Jul 18, 2012
    386
    13
    My Weller gun I have had since I was in High School back in 1975.
    I decided to repair it since the handle had cracked into pieces I had used tape to hold it together. Seeing it gets hot, I decided JBWeld epoxy would be ok.
    I always liked the little light.
    I think I will measure the volts, see if I can come up with something. Maybe a 12vdc dash - parking light bulb with a resistor - diode?
     
  4. JohnInTX

    Moderator

    Jun 26, 2012
    2,347
    1,029
    I have a 2.5V .3A bulb in my 8200 (E10 base). The original was a #222 I think. IIRC, the 222 was prone to burnout. The current bulb has lasted years. A search on 222 bulb will do it.

    EDIT: Reread and saw yours has a wedge base. Nuts. Maybe this will help someone else that has an older? 8200 with the screw base.
     
    Last edited: Mar 18, 2015
  5. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,058
    3,820
  6. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,995
    745
    put a white led in , never burns out..
     
  7. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    an led would require modification, the bulb is using ac not dc.
     
  8. wayneh

    Expert

    Sep 9, 2010
    12,127
    3,049
    An LED is a diode and works fine on AC, as long as the reverse voltage is low enough (<5v?). What is the voltage across the poles of a soldering tip? I suspect it's too low to light an LED, not too high for it.
     
  9. sdowney717

    Thread Starter Member

    Jul 18, 2012
    386
    13
    I believe it is using partly the AC voltage coming from the switch before it runs into the transformer coils.
    I dont think it is a full 120vac since one cord AC line wire goes only to a transformer coil wire, the other cord AC line wire is attached to the switch. And the buln is attached across the 2 upper switch solder lugs to which are also attached 2 more transformer coil wires.

    Ok, measured the volts as 13.8vac.
    I think a 7194 bulb from a car light should work fine.
     
    Last edited: Mar 20, 2015
    Lundwall_Paul likes this.
  10. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    it uses the secondary voltage from the transformer. not 120 volt line voltage, around 2.5 volts ac, on the older ones anyway.
     
  11. wayneh

    Expert

    Sep 9, 2010
    12,127
    3,049
    Your tip may be bad and that's what blew the bulb. There should not be that high a voltage across the tip. Or did you say the bulb is NOT in parallel with the tip?
     
  12. sdowney717

    Thread Starter Member

    Jul 18, 2012
    386
    13
    The bulb is not electrically connected to the tip at all.
    The tip is just a single loop inside a transformer which gives it high current to get hot and very low voltage.
    The bulb socket volts measures 13.8 on low and high switch trigger.
     
  13. wayneh

    Expert

    Sep 9, 2010
    12,127
    3,049
    Ah, OK, good. In a post somewhere I had read that it was. That poster must have been mistaken.
     
  14. sdowney717

    Thread Starter Member

    Jul 18, 2012
    386
    13
    I got a two pack of 168 LL bulbs from walmart for $4.50
    They work good in the solder gun.
    A 194 bulb is less watts at 3.9 versus 4.8 watts for the 168 bulb, which makes more lumens.
    Brighter is better, it feels like a good brightness level with the 168 bulb.
     
    wayneh likes this.
Loading...