[ale] [OT]: one for the EE's...

[jemarasco at bellsouth.net]

:D
The potentiometers I'm familiar with are in old Navy Nuclear power systems.  They would dissipate lots of heat.  I believe the internal resistance of a battery is <0.5 ohms.  If the circuit current is less than 1A the potentiometer would have to dissipate >0.5 watts.  That would be the spec Robert would look for.

Diods/LEDs are extremely low resistance components that will burn out in an overcurrent situation.  Robert will need an inline resistor to make the LEDs work right.  LEDs are p-n junction devices that require a biasing voltage drop.  Robert will need to considered the size of the power source and LED voltage drop when determining the number of series LEDs to include.

If Robert uses four series wired 3.7 V LEDs then I would suggest a 30V power source and (assuming an ideal power source) a 1K resistor to achieve a 15 mA circuit current.

Using the power source he has (6V), I would suggest wiring the LEDs in parallel and using a 150 ohm series resistor.

Different LEDs might have a different voltage drop and require different size resitors to achieve optimal current.

Good Luck! :)


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