1. Push the battery connector wires into the breadboard. In Figure 3, below, the red wire is inserted at E2. (All of the holes in row 2, from A to E, are now connected to the positive lead from the battery). Insert the black wire into the breadboard (hole E4). All row 4 holes from A to E are now connected to the negative battery lead.
2. Don't connect the battery to the battery holder yet. Connect the battery on the last step to avoid burning out either the LED or the FET.
3. Connect the middle transistor lead (the source) to the red battery lead. This is in hole A2 in the example below.
4. Insert the drain lead from the FET (left-most wire when viewing with the flat end in front) into the breadboard (A3 in the diagram).
5. The gate wire serves as the antenna, so it is not connected to the breadboard. Bend it so that it points away from the other leads.
6. Note that the LED has a flat region on one side. Connect the LED lead closest to the flat region to the black battery wire (negative). This is hole C4 in the example.
7. Connect the other LED lead to the drain lead of the FET. This is hole C3 in the example.
8. Double-check the connections, then connect the battery. The LED should glow red.
9. Use clear tape to hold down the battery, and also to secure the two leads from the battery.
10. You are now ready to experiment with electric fields!
11. Choose two objects from the triboelectric series and predict which objects will have a negative and which will have a positive charge after they are rubbed together. Write your predictions down in your lab notebook.
12. Now rub the two objects together. For example, run a plastic pen through your hair and hold the pen near the antenna (the unattached gate wire). Record your observations in your lab notebook.
Notes:
1. The charge on an object will dissipate if you handle it, especially if your hands are slightly damp. By handling the object, the charged particles are transferred from the object to your skin. You can keep the charge from being lost by isolating the charged object; for example, by suspending the object with string made out of nylon or some other insulating material.
2. Remember, objects with a negative charge will make the LED get dimmer as they are brought near the antenna. Objects with a positive charge will make the LED brighter. It is harder to see the LED getting brighter since is already pretty bright, but it is possible if you are careful.
3. The LED might turn off after the circuit is exposed to a strong positive field. It can be turned on again by waving a negatively charged object (such as a plastic pen that has been run through your hair) near the antenna.
13. Try each pair of items at least three times. Are your results consistent? Record your observations in your lab notebook.
14. Try walking across a carpeted floor then bringing your hand near the circuit. Try this wearing tennis shoes, just socks, or your bare feet. What happens? Why?
15. Try rubbing one end of a plastic ruler with a piece of cloth. How far does the negative charge extend over the ruler? (You can ';neutralize'; the ruler between trials by touching it all over with your hands. This works best if you have slightly damp socks on.)
Electricity Science Project completed charge detector circuit.
this is the website for more info: http://www.sciencebuddies.org/science-fair-projects/project_ideas/Elec_p050.shtml?fave=no%26amp;isb=cmlkOjM4MDg1Mzksc2lkOjAscDoyLGlhOkVsZWM%26amp;from=TSW
can you help if you have time thxI'm making a project but i cant make sense of the procedures?
If you can't make sense of the proceedures then perhaps you should select a different project. As an engineer you have to be able to get it, or you simply will not be able to handle the course of study required to become one. I am not saying this to be mean, it is simply a fact, that out of 100 students enrolled in an electrical engineering program only 30 will graduate. If you can not figure this out yourself then perhaps you should choose another course of study.
No comments:
Post a Comment