Resistor sizes
- Thread starter rhyso
- Start date
It depends on how much current you want. I suggest no more than 20mA for a seven segment display. Luckily there is a formula. If the LEDs drop 2 volts then you can calculate the resistor as so:
\(
R = \frac{V_{in}-V_d}{I}
\)
\(V_{in}\) = 6V, \(V_{d}\) = 2V, \(I\) = 20mA
For this we calculate 200 ohms. The closest standard E12 value is 220 ohms, so use 220 ohm resistors.
\(
R = \frac{V_{in}-V_d}{I}
\)
\(V_{in}\) = 6V, \(V_{d}\) = 2V, \(I\) = 20mA
For this we calculate 200 ohms. The closest standard E12 value is 220 ohms, so use 220 ohm resistors.
