Output Devices | Group Assignment

Task

Our assignment this week was to measure the power consumption of an output device of our choice.

Testing

We decided to go with a simple test on Aaron's output device, a white (diffused)LED with a maximum power dissipation of 80 mW at 25 °C.

Generally, to calculate power, you need current and voltage values because Power = Current x Voltage. So we needed to measure the current running through the LED and the voltage drop across it while the circuit is on. This can be easily done using a digital multimeter, and connecting it once in series for current measurement, and once in parallel for voltage measurement.

Measuring Current in Series

Current measured was 3.30 mA.

Measuring Voltage in Parallel

Voltage drop measured was 2.943 V.

Power Consumption

Power consumed by the LED is 8.92 mW, which is about 11% of the maximum rating from the datasheet.