What you got here is not a Variac, and 100 watt light bulb will limit the final power to 100 watts.the output of a light dimmer switch is not intended to feed an electronic device, especially if it has a transformer in it.
I can certainly understand that you want to baby those electrolytics.
In any case, I am glad you got your amp powered up. The bulb in series DID do something, it did limit the current to the amp and created a voltage drop across the bulb, which would lower the voltage to the amp by an amount dependant on the resistance of the bulb and of the amp. The resistance of a bulb changes tremendously from being cold to warming up to being hot. You would have had to measure it to see where it wound up, but you don't need to anymore. A 100 Watt light bulb would by itself, limit the max current (when fully heated up and bright) to less than 1 amp (approx 870 ma). Did the bulb light up at all when you tried it out?
Cool; thanks.
yup, kind of what I said in post #2.
Your graphic in your first post shows the bulb and amp wired in parallel, not in series. So, the bulb and the amp each got full voltage...and that is why "the 40 watt and the 60 watt bulb both lit up what seemed fully." Glad you got your amp running, but you had not done anything that would have warmed it up any more slowly than usual unless the wiring you used was too small to carry the combined load and worked as a resistance "load" that put some of the energy off as heat.
Actually Lee, they are electrically in series: The power hot goes into (through) the dimmer, then through the bulb, then through the amp, and returns to the Neutral to simplify it. (ignoring the wire colors the OP drew and being 115 volt crcuit). The bulb and the amp are definitely in series. If that were a true Variac (brand name) variable transformer, it would be reducing the original voltage and supplying another voltage to the real load (the bulb and the amp in series, as drawn).
So this time the Jelly is the electrolyte? S'funny mon!
If it were in parallel, I would expect it to have looked like this:
The drawing definitely shows parallel, else it would have looked something like this:
In that great original sketch, I cannot see the screws on the bulb socket. If I were trying something like that, I would be using a bulb pigtail socket, and it would be in series. I guess I cannot read into other people's thoughts too well and I assume too much, but he said he WANTED it to be in series. You are right, just because he WANTED it to be in series does not mean he made it that way. Funny thread we got going on this. what a bout the red by the way, lol?
