CS250 Lab 4: Electrical Practice
Due Monday, March 2 (preferably before the midterm)
This lab is a set of questions about topics that I'm concerned might be a problem on the midterm. Consider it a set of review questions.
1. Diodes allow electrical flow in only one direction, and capacitors store current. Draw a circuit that will take an AC signal and use it to keep a capacitor filled, with the caveat that the capacitor will discharge partially while the current is reversed. This is called a half-wave rectifier if you want to look up the answer, but make up the circuit first!
2. Suppose you want to run a 12 volt light bulb with the same resistance as we measured in class under load (12.45 ohms), but you have only 120v power from a wall outlet, a potentiometer, and a wall outlet. You can wire the light bulb in series with one half of the potentiometer, and add whatever number of ohms of resistance you like. What should you set the resistance to so the bulb has 12 volts? Note: For regular light bulbs with a filiment are equally happy on AC and DC.
3. The answer to the previous question worked briefly, but the potentiometer caught on fire. How many watts of power did you put into it?
4. Luckily, you have a box of 100 potentiometers. Suppose you set them all to the same value. What value will you set them to, and how will you wire them to divide the load evenly between them? Don't draw a complete circuit diagram with 100 poteniometers, just enough of one to clarify your plan.
5. Suppose you're making a new type of gate, called an ORAND. The ORAND has four inputs, A, B, C, and D. It outputs the result of (A and B) or C or D, and only uses 4 transistors. Draw a circuit diagram for this gate.
Turn in your answer on Canvas, or write it on paper and show me.