RE: (ET) 36v bulbs

["Elie, Larry (L.D.)" <lelie ford com>]

Good point Bob.  I stand corrected.  

The effect will indeed be just as great.  That's how an RTD works.  The 
formula is (Change in R @ temp. T)/(R @ 20C)=(temperature resistivity 
coefficient times the change in T).  If the bulb glows white hot, the 
resistance has changed.

Having said that, since the low resistance path is the resistor, the 
current through the bulb is still not that great, and it probably will 
still work.  As the resistance increases, the current through the bulb 
will just drop a bit.

Larry Elie


-----Original Message-----
From: Bob Murcek [mailto:RMURCEK geisinger edu]
Sent: Monday, May 06, 2002 10:17 AM
To: elec-trak cosmos phy tufts edu
Subject: RE: (ET) 36v bulbs


I'm not sure if the effect will be as great with a small bulb like that 
for the dash as with larger bulbs, but the cold and hot resistance of a 
bulb can be dramatically different.  I.e., measuring the bulb's cold 
resistance may give you an unrealistically low reading that would cause 
you to make the resistor way too small.

If you know or can measure the bulb's current draw, it would be safer to 
calculate the hot resistance by dividing the operating current into 12V.

>>> "SolidTech" <SolidTech qwest net> 5/6/2002 9:51:13 AM >>>
Another slightly different approach.  If you move the battery tap from B6+
to B2+ you change the lighting voltage from 12v to 36v.  Then from the
schematic the headlights and dash light are all currently in parallel.  So,
you can use the 36v bulbs for the headlights and put a resistor in series
[R(s)] with the dashlight bulb to keep it at 12v.  To do that, just measure
the dash light's resistance [R(dl)] - then:

I(dl) = 12 / R(dl)

R(s) = 24 / I(dl)

- - joe
Joseph Rock
E-15 & MagnaTrac Hydro 5000 in Colorado

  -----Original Message-----
  From: owner-elec-trak cosmos phy tufts edu 
[mailto:owner-elec-trak cosmos phy tufts edu]On Behalf Of Elie, Larry 
(L.D.)
  Sent: Monday, May 06, 2002 7:10 AM
  To: 'Eric Miller'; elec-trak
  Subject: RE: (ET) 36v bulbs


  For the dash light, you can just make a simple 1 resistor divider.  If 
you
know the resistance of the bulb (by measuring it) you essentially add a 1
Watt resistor in parallel to it with a value of about 1/2 of the resistance
of the bulb.  Here you don't waste very much power.

  Larry Elie

  -----Original Message-----
  From: Eric Miller [mailto:ewmiller erols com] 
  Sent: Sunday, May 05, 2002 5:22 PM
  To: elec-trak
  Subject: (ET) 36v bulbs


  Hello Jeremy,
    Sorry for taking so long to reply but, it took me a while to find where
I last put some that I bought. I came across some 36v bulbs with the two
contacts on the bottom of the bulb that fits the ET head light socket. The
box they came in is from Hyster, Unisource(TM). I guess they made 36v
forklifts? Is anyone one on the list familiar with Hyster or if they made 
an
36v electric forklift? The part number is  3015692. Description: Bulb 36v
B9.  The only markings on the bulb are "Taiwan" and the code "SP5".
    I bought these at an old Surplus store a couple of years ago, located
out in the very small town of LaVale, MD. I went back to the store on 
Friday
to find more bulbs and look for other interesting stuff that I really don't
have the room for. When I got to what "used to be" the dimly lit back part
of the store, I fell to my knees... all the old surplus goodies are no
longer there! I almost started to cry. The store manager said it was just
too costly to keep stuff like this around because it does not sell much. 
The
same space he said is now being used to shelf more commonly sold goods that
have a higher turn over rate that generates more revenue for them. I had
bought several old electric motors and many neat old used electrical 
gadgets
and parts from them over the years. Now it has all been replace with the
same hardware and products that can be bought at just about any hardware
store. I really loved those old types of stores.
      Next step would be to find a Hyster dealer and call them and see if
these bulbs are still available. Has anyone found a 36v replacement for the
dash light?
        Eric Miller