Need more help with LEDs

A

ANTlabs

New Member

• Oct 20, 2009

• #1

I need a circuit that makes 15 green LEDs fade slowly in and out every 30 seconds. I also need to know what batery this will need for it to run for 2 hours.

Thanks

 

Last edited: Oct 20, 2009

birdman0_o

Active Member

• Oct 20, 2009

• #2

As I said in your previous post 15 Leds at 20mA will be :
Iav = 50% *20mA * 15 = 150mA, using three AA batteries this circuit can last above and beyond 2 hours. 150mA * 2 hours = 300mA hours.
P = IV
Pav = 50%IV *15 Leds
Pav = 0.5 * 20mA * 3V * 15V
Pav = 0.45W
Now you need to account for the power dissipated in the resistors etc.

This is just to get the idea accross...

 

D

dawhale

New Member

• Oct 20, 2009

• #3

Thanks for this info. Good post!

DD

 

K

ke5frf

New Member

• Oct 20, 2009

• #4

I just took a look at your homepage ANTLabs, and noticed you have your normally open and normally closed switches backwards.

**broken link removed**

At least they appear that way if you have them labeled underneath.

Remember, switches and relays are always labeled in their resting or deenergized state in schematics unless otherwise noted.

 

microtexan

New Member

• Oct 20, 2009

• #5

Man, your web site really needs some work. Many mistakes and concepts.

 

A

ANTlabs

New Member

• Oct 20, 2009

• #6

Thank you two for the reviews, I have not been able to change any errors, though, It wontlet me on the sie! But please stick to he circuit. I only have 3 days left to gt it! can someone please post a schematic!!! It just needs to make the LEDs fade in and out.

 

Last edited: Oct 21, 2009