Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: turtle441 on April 22, 2018, 07:35:12 pm

Title: Bulb Wattage for Lightbulb Limiter
Post by: turtle441 on April 22, 2018, 07:35:12 pm

What’s the recommended wattage for the bulb in a light bulb limiter?  Is there a rule of thumb?  2 x amp wattage or something similar?  About to fire up a 15-18 watter, looking to build a limiter.

Title: Re: Bulb Wattage for Lightbulb Limiter
Post by: PRR on April 23, 2018, 12:59:29 am

For smoke test, "bigger than amplifier" will prevent smoke, but may not play OK.

For "nearly working" you want a lamp several times larger than the amplifier.

Note that a "18W" will certainly draw over 60 Watts from the wall. So think lamps like 100W, maybe 200W.

Note that it MUST be Incandescent (or Halogen). CFLs LEDs work very different.

Title: Re: Bulb Wattage for Lightbulb Limiter
Post by: turtle441 on April 23, 2018, 09:10:19 am

Thanks, appreciate it.  Now to find a hardware store that still sells 100W incandescent bulbs...

Title: Re: Bulb Wattage for Lightbulb Limiter
Post by: ArchieTop on August 12, 2018, 05:37:28 am

For what it’s worth, I was in a nearby Rural King store and they had 200W incandescent bulbs for $1.99. I thought of my dim light bulb setup and grabbed a few.

Title: Re: Bulb Wattage for Lightbulb Limiter
Post by: byoungblood on August 26, 2018, 08:59:22 am

I use a 200 watt, the lightbulb rules don't apply to high watt bulbs so incandescents are still easy to find.

Just remember your line voltage will drop across the bulb, for checking voltages you'll need to plug directly into the line.