Show more deatils please!! what is the power of lights you want to operate? Sure you must do calculations to know, how much energy you need to operate your lighting system, maximum volt and current. These lights are blinking or just stable lights?
First of all this website is pretty helpful, take a look on electronics components:
http://www.kpsec.freeuk.com/
I will try to make the idea clearer for you. Let’s make a stable lighting system consisting of 1 LED (5mm).
Basic information about LEDs (Light Emitting Diodes), check this link please:
http://www.kpsec.freeuk.com/components/led.htm
Components:
(5mm) Red LED -----> #1
Signal Diode (normal Diode) -----> #1
Resistor
Switch on- off
9V Battery
Before deciding the size of the needed battery for operating your system, you must know the forward current (IF) and forward voltage (VF) of the used LEDs in system. If you can’t take LED specs from supplier, you can use this table as a guide. The table below shows typical technical data for some 5mm diameter round LEDs.
Type | Color | IF
max. | VF
typ. | VF
max. | VR
max. | Luminous
intensity | Viewing
angle | Wavelength |
Standard | Red | 30mA | 1.7V | 2.1V | 5V | 5mcd @ 10mA | 60° | 660nm |
Standard | Bright red | 30mA | 2.0V | 2.5V | 5V | 80mcd @ 10mA | 60° | 625nm |
Standard | Yellow | 30mA | 2.1V | 2.5V | 5V | 32mcd @ 10mA | 60° | 590nm |
Standard | Green | 25mA | 2.2V | 2.5V | 5V | 32mcd @ 10mA | 60° | 565nm |
High intensity | Blue | 30mA | 4.5V | 5.5V | 5V | 60mcd @ 20mA | 50° | 430nm |
Super bright | Red | 30mA | 1.85V | 2.5V | 5V | 500mcd @ 20mA | 60° | 660nm |
Low current | Red | 30mA | 1.7V | 2.0V | 5V | 5mcd @ 2mA | 60° | 625nm |
Red LED (5mm): VF = 2.1(V), IF = 30mA.
Connect battery in series with, on-off switch, signal diode, resistor, LED. Let’s say that we are using 9V battery. Don’t forget that forward voltage of signal diode is 0.7V so volt after diode will be V(battery) – V (diode), 9 -0.7= 8.3V
Value of Resistance = ((V(battery) – V (diode) – VF) / IF) = ((8.3 – 2.1/ 30 X10-3) = 206.67 OHM, to use a standard value of resistance 220OHM (1/2W)
The link below show how to calculate value of limtting resistor:
http://led.linear1.org/1led.wiz
Kind Regards
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