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View Full Version : How do you reduce 220 volts to use an LED light.


Lancasterpa
Feb 1, 2011, 08:36 PM
I want to put an LED light on my transfer switch so I know when the power from the electric company comes on. I am using this in my home in the Philippines so my voltage is 220. I want to buy an LED from Radio Shack and hook this directly to the incoming wires from the electric company. The electrician already showed me which wires to hook up so I am good there. Here are the specs for the LED:

URL: http://www.radioshack.com/product/index.jsp?productId=2062549&clickid=prod_cs

Size is T-1 3/4 or 5mm
Clear lens color
Viewing angle is 54°
30mA (max)
Typical Voltage is 2.0, with a maximum voltage of 2.8V

If you have a better suggestion for a Radio Shack bulb I would appreciate that too.

Craig

medic-dan
Feb 1, 2011, 09:06 PM
You've got a couple of issues with doing this.

1. LED"s run on DC, not AC. You'll need a rectifier in the circuit.
2. Your resistor will be dissipating a lot of heat. You'll need a 8.2k ohm (82000 ohm) rated and able to dissipate about 7.5 watts of power. You'll need a power resistor not the cheap 1/2 watt thing at Radio Shack.

As an alternative, you might go to an appliance store and tell them you what you are doing. Quite a few stoves have a pilot light, 240 vac, that goes on when you turn on the burners. It would work fine in your application.

Lancasterpa
Feb 1, 2011, 10:15 PM
Brilliant, why reinvent the wheel. Thank you for the suggestion and I will follow that lead. Medic-Dan you rock. Craig