8mm Forum: Projector Bulb Overload

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Posted by Mark Kligerman (Member # 4354) on September 24, 2014, 11:18 AM:

I assume this is an extremely naive question, but I was wondering what would happen if you put a 100 watt bulb in a Super 8 projector designed for a 50 watt one? Could it work, or will the bulb burst?

Posted by Steve Klare (Member # 12) on September 24, 2014, 11:33 AM:

What happens depends on a lot of things.

For example there are two main ratings of a lamp, voltage and wattage. If you put a 120V, 100W bulb into a 12V, 50 watt projector, you'd be lucky to get any light out of it at all. basically nothing either bad or good would happen in that case.

Then again If you put a 12V, 100W lamp into a 12V, 50W projector you may be abusing the power supply that lights the lamp, and you may be overloading the capacity of the projector to keep the lamp cool enough for a long life.

As the projector's lamp supply voltage exceeds the lamp's rated voltage, things will go wrong more certainly, and more quickly too.

Without knowing the design limits of the machine, the way to find out is to plug in the new lamp, and let it run.

If five minutes later something fails, then you know.

(The bulb wouldn't burst.)

It's something people have tried here before, and often it doesn't end happily!

Posted by Paul Adsett (Member # 25) on September 24, 2014, 11:51 AM:

Steve is right. Using anything higher than the rated lamp wattage in a projector is going to permanently damage the machine. Don't mess with it!

Posted by Dominique De Bast (Member # 3798) on September 24, 2014, 01:00 PM:

The manufacturer's interest (in ordre to sell as much as possible) is (or should we say was) to advertise a projector as powerfull as it could. So it is logical to assume that if they state(d) 50 watts, there is a good raison. So be carefull...

Posted by Terry Sills (Member # 3309) on September 24, 2014, 01:07 PM:

My understanding is that by fitting a lamp of higher wattage than is recommended by the manufacturer, you would be overloading the transformer which supplies the power to the lamp with possibly disastrous results. Definitely not recommended.

Posted by Maurice Leakey (Member # 916) on September 24, 2014, 02:42 PM:

Agreed. The transformer would not last for long.

Posted by Steve Klare (Member # 12) on September 24, 2014, 04:17 PM:

Possibly they'd use the same transformer for a 50W bulb as a 100W bulb. There could be situations where if they bought the same transformer for both types of machines, the bigger purchase quantity would lower the unit price to the point where it's cheaper to only have one 100W capable transformer in everything.

-only the manufacturer knows for sure.

Until you blow the thing up you won't know one way or the other.

Posted by Pasquale DAlessio (Member # 2052) on September 24, 2014, 07:41 PM:

Somebody tell me watts going on here! [Big Grin]

Posted by Steve Klare (Member # 12) on September 24, 2014, 07:53 PM:

Power Corrupts!

(Absolutely! [Big Grin]

)

Posted by Terry Sills (Member # 3309) on September 25, 2014, 02:05 AM:

Only absolute power corrupts absolutely!

Posted by Jean-Marc Toussaint (Member # 270) on September 25, 2014, 02:26 AM:

And with great power comes great responsibility.

Posted by Paul Mason (Member # 4015) on September 25, 2014, 03:30 AM:

Mark,
There are different lamp holders as well as lamp ratings. The 12 volts (V))100 watts (W) lamps by and large do not fit into projectors with 50W because the 50W lamps are usually "diving helmet" designs rated at 8V not 12V. The projector thus only provides 8V from its transformer.

The 12V 100W lamps were made in many forms including diving helmet and parabolic reflector most of whom will not fit. If you find a 100W lamp that physically fits such as the A1/203 diving helmet replacing the A1/17 (sorry I don't know the US codes) or an A1/231 parabolic mirror halogen replacing the A1/229 all you will get is a dimmer light than the original 50W.

This is because the 12V 100W lamp has a slightly higher resistance (1.44 ohms) than the 8V 50W lamp (1.28 ohms). However there should be no damage to the projector since your 100W lamp is running as a 44W lamp.

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