Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
If i have a 12VDC source, and i have connected a LED that is rated at 5V, and of course I have a resistor connected in serie with the LED. What will the voltage be across the resistor and across the LED?
An LED is a very nonlinear load. It may be 5v at the rated current, but only 5.25v at twice the rated current and 4.75v at half the rated current.
So, you might be able to assume that no matter what the current (within reason), the LED is around 5v. From there, you assume there's 7v across the resistor and you can choose a resistor size that creates the desired current.
If the LED is rated at 5v it will drop 5 volts and the resistor will drop the rest of the supply voltage, so u have to know the current needed to light the LED without damaging it and depending on that current u choose the correct value of the resistor which will drop about 7 volts. :wink:
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.