Introduction to electrical and computer engineering ENG1450 All Labs

ENG 1450 Introduction to Electrical and Computer Engineering

Lab 6

Simple Hand-Crank Flashlight
&
Electrocardiography (ECG)



Name: _______________________________



Student Number: _______________________________



Lab Section: _______________________________



Instructor: _______________________________



Date: _______________________________




Did students clean-up after the lab? _________________________
TA signature



ENG
1450
-­‐‑
Lab
6
Fall
2019-­‐‑v1
Page
1



, Part A: Hand-Crank Flashlight

Build the circuit of Figure 1.




Figure 1: Charging circuit for the hand-crank flashlight.

Connect your DC motor to the circuit as the generator power source. Use a 15,000 µF capacitor
to store the generated electric charge. The capacitor that you will be using is a polarized capacitor.




Figure 2: Polarized capacitor.

Note: The side of the capacitor with the dashed lines is the negative voltage side. The other
side of the capacitor should be connected to the diode.

Have the TA check that you have connected it correctly before you proceed any further.
Operating a polarized capacitor the wrong way can damage it.

1. Turn the shaft of your motor slowly to charge the capacitor. A slow turn will generate around
8 V. If you turn the motor shaft the wrong way, you will make a negative voltage, and the
capacitor will not charge because the diode will block current flow. Use your multimeter to
verify that you are charging your capacitor.


VC = ______________ V

Note: Be careful that you don’t turn the motor shaft too hard, as you don’t want to break it.

Don’t get excited and turn it too fast to make higher voltages. If you exceed 16 V, the
capacitor will be damaged, and significantly higher voltages can make it explode.

In time, the charge on the capacitor will slowly leak away. It is not a perfect device.



ENG
1450
-­‐‑
Lab
6
Fall
2019-­‐‑v1
Page
2