No subject

+4.5V ------------------------ +D1- ----------- +D2- ------------------>3V 
Output

-(GND) -------------------------------------------------------------------*

Where D1 and D2 are 1N4001 diodes or similar (1N400x) the various "x" change 
the current rating. And + means anode, - means cathode (the side with the 
line).

And get 3-4 Diodes, you might want to start with 3 diodes and your load, see 
how it does, then back off to 2 diodes.

This is called a "diode regulator" and a great way to downstep a voltage in 
a pinch without a full regulator. But, its input (the 4.5V) needs to be 
regulated, since the regulation of the the output is only as good as its 
input --

Andre'



----- Original Message ----- 
From: <john at cozmicfunk.com>
To: "The Robot Group Mailing List" <robotgroup at puremagic.com>
Sent: Thursday, April 03, 2008 2:10 PM
Subject: [Robotgroup] LED's and Resistors?


Hey there. I have a basic question for anyone who can help.

I have a 4.5 volt (3x AA) DC powered LED circuit with White LED's (x-mas
lights string from Walgreens etc.) and I am adding 3 volt Red LED
flashing circuit to it. I need to step down the voltage reducing the
input for the flasher to 3 volts ( obviously reducing 1.5 volts from the
input).

I have a couple different flasher lights and LED compartments (all 3
volt DC) I am adding down the line for my hallway sections on my models
sets. I understand there is color coding on the resistors, which ones
should I get and where do I find them, Rat Shack , Fry's etc.

This should be simple for people like Andre and Vern and Done and Gray etc.
Thanks, John

_______________________________________________
Robotgroup mailing list
Robotgroup at puremagic.com
http://lists.puremagic.com/cgi-bin/mailman/listinfo/robotgroup