LED help

[biferi]

I am putting a LED in a picture I have and I will be connecting it to a Switch and Battery Pack.

I know the only deferance between Tripple A Batteries and Dabble A Batteries and C Batteries and D Batteries is the mA go up but they all have 1.5 Volt.

Am I right that if I use a D Battery Pack the LED will last longer then if I use a Dabble A Battery Pack?

The Dabble A Battery Pack will hold 4 Batteries in Series so the Voltage will be 6.0 Volts and the MA will stay the same.

Now the D Battery Pack will holkd 2 D Batteries in Series so the Voltage will be 3.0 Volts and the mA will stay the same.

 

[MikeMl]

A LED is a device that needs to be driven by a circuit that holds the current through the LED more-or-less constant. In a simple case, you do this by putting a resistor in-series with the LED(s). Here is a calculator that will show you what resistor you need.

You have choices: How many batteries to connect in series (determines the supply voltage).
How many LEDs to connect in series. (The total forward voltage across the LEDs must be less than the supply voltage)
How long do you want the LEDs to stay lit. Determines the size (capacity in mA-hours) of the batteries to use.

 

[biferi]

Well I will have one LED.

And yes I know a Resistor will slow down the flow of Current so the LED will last longer.

I want a LED that will Glow Bright not a Dim LED do they sell any and what will I look for?

 

[Ross Craney]

Well I will have one LED.

And yes I know a Resistor will slow down the flow of Current so the LED will last longer.

I want a LED that will Glow Bright not a Dim LED do they sell any and what will I look for?

Go back a couple of years & the standard LED was in the order of 50 - 100 mcd. Now days the super brights go up around 30000 mcd. That will just about blind you if you look directly into them. Standard sizes are 3mm 5mm & 10mm. You will also need to check on the viewing angle.