View Full Version : Switch activated LED
Tyler Shane
Jun 17, 2009, 02:11 PM
Ok so I have a toggle switch, a 9v battery with harness and wiring(red/black), and an LED...
How do I connect the 3 things to have the LED come on and off by the use of the switch?
The toggle switch has 3 prongs on the bottom labeled: Power, ACC, and Ground...
The LED is 5000amd and has 2 prongs on the bottom(1 short/1 long)
Perito
Jun 17, 2009, 02:51 PM
The 9 volt battery has two poles, + and -. The LED has two poles, a cathode and an anode. You need to connect the battery (+) to the switch. The other end of the switch to the LED's anode. The LED's cathode then connects to the - of the battery. The long lead of the LED is its anode.
Note that most LEDs require an inline current-limiting resistor to keep them from burning out from current overload. You size the resistor (Ohm's law) based on the amount of current you want to flow through the LED (assume 0.5 volt voltage drop across the LED).
The switch's Power lead is probably where power comes into the switch. ACC is probably where it comes out. I would think the ground would be a protective ground. However, I'm unsure of this switch.
KISS
Jun 17, 2009, 03:01 PM
p's ground explanation wrong.
KISS
Jun 17, 2009, 03:05 PM
Get 1k resistor at radio shack. Will answer tomorrow.
KISS
Jun 18, 2009, 12:23 PM
I promised an answer. I don't have a computer now, so some answere are limited based on responding via my cell phone.
The terminals POWER, ACC and ground suggest something like a 12 V switch with an integral light.
If you place 12V between power and Ground, then the switch will illuminate in the ON position. In your application eliminate the ground.
The LED needs between 10 and 50 mA typically to light and you need to read the specs to be sure. A 1K resistor will give 9 V/1000 ohms or about 9 mA. 1 mA = 0.001 amps.
An LED is directional. Usually it won't be damaged by reverse polarity. There is a short and long lead, but there is also a flat usually. I use the flat. The flat is basically the straight line in the diode symbol or the + side.
Connect the resitor, the switch (PWR,ACC terminals) and the battery in series. Folllow the -(negative) of the battery until the above ends. Connect to the banded side of the LED. Connect the unbanded side to what's left. Operate the switch. The led should turn on and off.
If the switch is LED based, you should also be bale to connect the negeative of the 9V battery to the Ground terminal of the switch and have the switches illumination work too.