Light bulb limiter parts question

[MakerDP]

If I wanted to build this:

https://taweber.powweb.com/store/safestart_schem.jpg


Is this an appropriate bulb?
http://www.amazon.com/dp/B00HJCFY8U?psc=1

[sluckey]

You don't need a special purpose bulb. Just get a common household incandescent bulb (not CFL). My limiter is the same as the Weber schematic except my switch is a pushbutton.

[MakerDP]

yeah i'm aware of that. I just like the compact design of this limiter.

[MakerDP]

 

Thanks.

Here is what the Weber kit looks like. I can easily do something similar.

[MakerDP]

I can get a small 75W halogen bulb at my local Batteries + Bulbs. Will that be sufficient or does it have to be 100W?



edit: ah never mind... I can get the 100W halogen bulbs at my local Lowes.

[PRR]

Most of the "100W" bulbs I have been finding are "100W Equivalent" halogen and only eat 72 Watts.

I did find a 100W Large Globe. (I like large, not small, for lower burn hazard).

> Will that be sufficient or does it have to be 100W?

Depends what you are running, and how you want to test it. ANY lamp will prevent wall-wire fire if your amp is dead-short. If you want to see the amp "run" (poorly due to low voltage) the lamp should be bigger than the amp's total power (not output power). Since even a Champ runs over 50 Watts, a 72W will starve it, and you won't get even a decent partial-voltage test (the tube heaters may not get hot enough to loosen any electrons). I'd go 100W on small amps and 150-200W on large amps.

FWIW: I have a "37 Watts" duct fan which is too loud and blows too much. I tried a 40W lamp in series but it hardly ran. I tried a 72W halo and it is nearly there. I tried a true 100W lamp and it was too much (for my purpose). I'm back with the 72W. I may end up with a mess of resistors; but I like the lamp because it will pass a big starting current cold then fade-back as the filament heats. The "72W" glows like a 7W Xmas bulb, and the 100W I can hardly see glow.

150W and 200W plain incandescent lamps are readily available at Home Despot, so I am sure Lowes has them. I use them in my garage, where the total running hours does not justify a more efficient lamp, and the instant-on and stray heat is a bonus on cold dark days.

[MakerDP]

Most of the "100W" bulbs I have been finding are "100W Equivalent" halogen and only eat 72 Watts.

I did find a 100W Large Globe. (I like large, not small, for lower burn hazard).

> Will that be sufficient or does it have to be 100W?

Depends what you are running, and how you want to test it. ANY lamp will prevent wall-wire fire if your amp is dead-short. If you want to see the amp "run" (poorly due to low voltage) the lamp should be bigger than the amp's total power (not output power). Since even a Champ runs over 50 Watts, a 72W will starve it, and you won't get even a decent partial-voltage test (the tube heaters may not get hot enough to loosen any electrons). I'd go 100W on small amps and 150-200W on large amps.

That's good info.

I've seen other limiter designs that have two bulbs, each with it's own "limit/bypass" switch. That would make it easy to do 100W & 200W in one compact desktop design like that Weber box. I could do a three-way toggle where middle is bypass, up is 200W with two bulbs and down is 100W with one bulb.

[PRR]

> do a three-way toggle

3-Way 50-100-150W and 50-200-250W *true incandescent* light bulbs are STILL available if you act fast. (3-way curly-tail and LED lamps are starting to come-in.) A 3-way replacement socket is readily available in the home-store. Neat way to get several settings. You do want to file a notch-mark on the knob and label the settings. For calibration/testing, plug a 1,000+W toaster in the "amp" socket so the lamp will light and you can see which setting is which, or when one of the two filaments has burnt-out.

[kagliostro]

Initially I misunderstand and I was thinking PRR suggests to use a toaster in place of the lamp (a toaster limiter  )

 

Then I realized what he really was saying 

Franco