6V SLA Dropping resistor for a 5VDC Filament Supply

[chrismercurio]

I'm dangerously close to finishing a 71a line stage but my DMM is suspect and giving various inconsistent values and won't measure 1% resistors accurately.

Can someone lend me a hand and tell me the approximate fixed resistor value to lower a 6v SLA to 5V for a 71a .25a filament supply? Even better would be tell me how to apply ohms law or KVL/KCL to the current scenario so that I don't have to ask such a pedestrian question again.

I know I need a new DMM but that is going to have to wait for a few weeks.

Thanks!

 

[astouffer]

Number of volts to be dropped divided by the current.

Although what you really need is a low dropout regulator. Using a resistor will give you no overhead when the battery starts to lose voltage.

 

[chrismercurio]

So....1v/.25a=~4ohms?

 

[DF96]

Yes, Ohm's law.