|schreef in bericht
...
|
|I have this old fluorescent desk lamp from the 60s at the latest that I'm
fixing. It weighs a ton, has been passed down from my father-in-law, and it
just retro-|cool. According to him it's always worked, except the F15-T8
bulbs are possibly original and very worn out, and only one bulb ever
lights. I've been told this |has always been a problem, and holding the
start button for a long time will sometimes get both to start. I've never
been successful but I don't like this and |want to fix it.
|
|Upon reverse engineering it I come up with this schematic (it's rough,
drawn in Paint!):
|
|
|https://imgur.com/a/0YYKV
|
|I'm no fluorescent light expert, but how the start button is connected to
both lamps seems odd to me, a little like directly paralleling LEDs or neon
bulbs after |the limit resistor. If I disconnect one bulb, the remaining
always starts. I doubt this design would ever work very well....would it?
|
|If I manually start each light by disconnecting the start button wires and
momentarily shorting the two pins at opposite ends of each lamp, they each
start |right up. My plan is to modify it with a DPDT relay with 120VAC coil
so the start button drives the coil, and each lamp has it's own set of relay
contacts. I'm |sure this will work, but.....WTF with the original design?
Is this normal? I doubt it's even been modified, and see no good way to fix
it without adding a relay |or a multipole start switch.
|
|I'm a little surprised to see some that seems this hokey (to me) in
something this old.

In a similar case, replacing the startbutton worked for me. Still don't know
how or why. (A little frustrating.)

Otherwise, seperate both lamps + ballasts and use two startbuttons.

petrus bitbyter