hardest question in the world

[dannyboy77]

big gold star to anyone who can answer this really hard question as an hour in malpin and searching google cant answer this! what resistor would i need to drop 5v to 0.5v think probably 1-0.5A as it will be coming out the ECU dont mind if have to buy a couple of resistors as they arent too expensive!

thanks!

[madcampbell]

This might help....http://www.doctronics.co.uk/resistor.htm

[dannyboy77]

nope

[slobodan]

Resistance is futile.

[galooph]

big gold star to anyone who can answer this really hard question as an hour in malpin and searching google cant answer this! what resistor would i need to drop 5v to 0.5v think probably 1-0.5A as it will be coming out the ECU dont mind if have to buy a couple of resistors as they arent too expensive!

What are you trying to hook up to the ECU?

The voltage drop across a resistor is proportional to the current flowing through it. Using Ohms law, R = V/I, 4.5V drop at 1A gives you 4.5/1 = 4.5Ω and 4.5V drop at 0.5A gives you 4.5/0.5 = 9Ω. Not only that, but you'd be pumping out a fair amount of heat too - 4.5W at 1A.

How much current do you need at 0.5V? Sounds like a simple transistor driver would be better.

Dan