Week 9 Group documentation

This week we used a multimeter to measure the power consumption of a motor in a circuit. First we measured the power of 4 AA batteries. We set the multimeter to 200v, and the measurement of voltage from the batteries was 6.4v. We then measured the voltage when the motor was running. To do this, we integrated the multimeter as part of the circuit, before the motor. This produced a measurement of 77mA. The motor was put under load by attaching a fan. The current exceeded 200 mA and therefore gave inaccurate results. To fix this we changed the settings on the multimeter to 20A and measured the current to be 0.12 amps. This was important because the microcontroller can only give 40mA or it will overload. Therefore to power this fan we would want a separate source of power.