Hi all,
I'm experimenting with a light/dark circuit with an LDR.
Which brought me to something else that i can't seem to figger out.
- How can you calculate the change in voltage drop & current trough a resistor with changing source voltage.
Example :
Led= 2v , 20Ma
Source voltage = 6 V
So i need to drop 4V over my resistor and limit the current to 20Ma for the LED.
4/0.02 = 200 Ohm ... so resistor = 200ohm
How can i calculate the change in voltage drop and current trough my resistor that stays 200 ohm if my source voltage is suddenly 5V ?
Thanks for the help
I'm experimenting with a light/dark circuit with an LDR.
Which brought me to something else that i can't seem to figger out.
- How can you calculate the change in voltage drop & current trough a resistor with changing source voltage.
Example :
Led= 2v , 20Ma
Source voltage = 6 V
So i need to drop 4V over my resistor and limit the current to 20Ma for the LED.
4/0.02 = 200 Ohm ... so resistor = 200ohm
How can i calculate the change in voltage drop and current trough my resistor that stays 200 ohm if my source voltage is suddenly 5V ?
Thanks for the help