91Views3Replies

# how do i connect 2 sets of leds that have different volts and mA's?

ok one set reads current: 20mA suppply: 3.2V and the other reads current: 25mA supply: 3.3V

91Views3Replies

ok one set reads current: 20mA suppply: 3.2V and the other reads current: 25mA supply: 3.3V

## Comments

11 years ago

steveastrouk's drawing is spot on, whatever your supply voltage is?_ simply add together one pair of Led's as 2 x 3.2 = 6.4volts then subtract from the supply volts, result will bel the voltage drop across R. Next apply ohms law, volts drop across R divided by current through Led's 20mA (0.02 amps) = value of resistor. Likewise voltage drop across R x 20Ma = wattage of resistor required. Apply the same calculations for your 3.3v 25 mA pair.

11 years ago

AS Sean says, here is a typical circuit. The R's are different for each set of your LEDS.

11 years ago

Use a single 5V power supply and drive them on parallel legs with appropriately selected limit resistors