120 volt LED?

[lanceh5]

I want to use a three-way 120 volt switch for an evaporative cooler and an LED to indicate if the power is on. This is in a two story house and the three way swtitch would power the cooler on or off from downstairs or upstairs. The rotary switch would be down stairs. Is there a 120 volt LED that would work?

[Mike]

yes any LED will with the right resistor. You also need to turn AC to DC for it.<p>Read this post at my forum for more info:
http://electronetbb.netfirms.com/ebb/me ... 1069208816

[Edd]

Oh how lucky you are to be in an arid situation that a cheaper running evaporative cooler can be utilized! My areas humididitity requires a refrigidididerated unit. <p>73's de Edd
[email protected] .........(Interstellar~~~~Warp~~~Speed)
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<p>[ August 08, 2004: Message edited by: Edd Whatley ]</p>

[rshayes]

Look for indicators in an electrical supply catalog. Anything that is connected directly to a 110 VAC line should be designed for this service and have an appropriate approval. Otherwise, the building code inspector may get interested, and it may affect coverage under fire and homeowner's insurance policies.<p>Often these indicators use neon lamps or incandescent bulbs. Some recent ones may use LEDs.<p>A transformer at the air conditioner which drops the voltage to the 12 to 24 volt level and isolates it from the 110 VAC line may be a reasonable solution. The circuit can then become a low voltage signalling circuit, with greatly relaxed requirements. Such a transformer may already be there if the air conditioner is controlled by a thermostat.

[dacflyer]

it would be a lot easier for you to just use a 120v neon indicator...they got them small , 1/4" hole or so...up to as big as 1" and they use hardly nothing as far as electricity...and just as many colors as leds....almost.

[lanceh5]

Thanks for your responses. I went to the local electrical supply store two weeks ago and ordered a Leviton switch 1203-PL which has a pilot light. I don't have the switches yet but they should work OK.

[Chris Smith]

The article in NV this month shows you how to use a cap instead of a resistor, to drop the voltage. Less draw.

[dyarker]

Don't have latest copy of NV yet (APO takes a week longer than CONUS delivery). Darn, I can't be first to the patent office.<p>Less draw, impossible; less apparent draw if you don't use imaginary numbers in the math to account for the phase shift of the capacitor, yes.

[Edd]

<<I went to the local electrical supply store two weeks ago and ordered a Leviton switch 1203-PL which has a pilot light.>>…make that TWO pilot lights in the switch as per reference, one in the side/surround backlite panel and one in the clear toggle handle.:
http://www.levitonproducts.com/Catalog/ ... VW13DKUQK2 F8JQWETE4ECW6D6PDAW8C&PID=1208
and for 2 switches, can we assume that your wallet is now $44.56 lighter?<p><<Note...pilot light switches require a neutral wire; lighted handle switches do not require a neutral wire >>
So if you are in an older house with an old wiring provision of no separate ground, that may mean that you might not get your desired pilot indication downstairs of the ac unit being on.
Seems like their switch pilot indicators are merely TWO NE2 lamps and two 100k current limiting resistors from each switch terminal to the ground rail.
Too late now , but the hand fabbed isolated/in line current transformers I mentioned will sense as low as a 60W load with 2 turns of the Romex/TW wiring looped thru the ferrite balun primary and 100 turns #30 on the secondary. No ground wire necessary. Cost about $2 max.
73’s de Edd<p>[ August 08, 2004: Message edited by: Edd Whatley ]</p>

[dyarker]

There is a bo-bo in the article. The phase shift is 90° if the circuit is pure capacitive. This circuit also has active and passive components. (capacitors and inductors are reactive)(Current leads voltage in capacitors)<p>I haven't done this math since college ('71), so I'll make an EWAG based on the relative voltage drops that the angle here is about 79°.<p>Pcap = 0.02A * 140V cos79° = .534W not zero<p>The voltage measured across the capacitor PLUS the voltage measured across the rest of the circuit is GREATER than the input voltage!<p>20mA from the outlet is 20mA from the outlet in either case. There's no such thing as a free lunch.<p>Using a capacitor instead of a resistor might be considered a discount coupon. <p>Cheers,