A while back, in another Usenet ng, someone asked about using an ordinary 120V incandescent lamp to slow down a fan motor. A number of posters replied that they had successfully done this. The usual discussion of the merits of doing this ensued.Then, one frequent poster replied that he had tried this with a small AC motor, and the 120V bulb, in series with the motor, burned out when the circuit was completed.There was much discussion, with many saying that it was impossible for any two terminal passive device in series with a 120V incandescent bulb on a 120V circuit to cause that bulb to burn out.Some even set up Spice simulations which were difficult because of the large variation in the bulb's resistance from cold to fully "on". The OP was asked to repeat the experiment, which he did several times, with the same results of the bulb burning out.The final conclusion, perhaps not shared by all, was that it was possible for a passive device to act in this way. One poster even showed Spice results with an increase in line current due to motor inductance. It was never proved that this increase was enough to cause the bulb to fail.I haven't tried the experiment myself, since I don't have a suitable small motor available, and with 120V incandescent bulbs on the endangered species list, I don't care to sacrifice even one! Some time ago, I did use a series 120V 100W bulb to slow down the compressor fan motor in my refrigerator, when the proper replacement was not available.I have my own theory and can postulate a two terminal passive device capable of behaving in this way. (It doesn't even need pre-"charged" condensers.)What say ye all?-- Virg Wall, P.E.

"Jim Thompson" wrote in message news:I'm de-lighted.Paul

Burn out 120V lamp on 120V circuit?

Aug 05, 2010 65 Replies

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Sylvia Else 15 years ago

Probably about the only way one will ever enlighten a greenie.

Sylvia.

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Jim Thompson 15 years ago

I like that "enlighten" ;-) ...Jim Thompson

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Spice is like a sports car... Performance only as good as the person behind the wheel.

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Paul E. Schoen 15 years ago

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

I'm de-lighted.

Paul

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Michael A. Terrell 15 years ago

What's wrong with Napalm?

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Jim Thompson 15 years ago

Fred, Your Node "2" change to "0" is correct.

Thanks!!

I've run it on ±28V with either terminal chosen as ground... now works properly. ...Jim Thompson

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Fred Abse 15 years ago

You're welcome!

-- "For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." (Richard Feynman)

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