Question

Mini Project Fall 2023 You and your lab partner are to design a circuit for measuring resistor values. Your circuit should have two input terminals where you connect the resistor to be tested, and should produce an output voltage that is numerically equal to the resistor value in KQ. For example, a 2.5k resistor would produce an output voltage of 2.5 volts. Your circuit must work for any resistance up to 5 KQ and produce a result that is accurate to within 5% of the resistor value you measure using a DMM. For resistors greater than 5k your circuit should light an LED, indicating "over range". When an over-range is encountered, the user should have the option of throwing a switch or, equivalently, changing one wire connection (not both ends of a wire!) so that the measurement circuit can measure resistors up to 50k with an output voltage that is numerically equal to the resistor value in k divided by ten. For example, a 25k resistor would produce an output voltage of 2.5 volts. Again, resistors greater than 50k should cause an LED to light. Scoring The maximum score for this lab is the same as the others, ten points. The design itself is worth eight points, and the lab report is worth two. To receive the full eight points, your circuit must meet these additional requirements: - Use only one power supply. Since our supplies are dual or even triple supplies, this means you could use +/- 9 volts if you needed it for something... - Circuit must not draw more than 50 mA - Use ten or fewer components, not including the wires of course. Procedure Before coming to the lab, design your circuit. When you arrive, show your schematic to the TA, then build it. Testing may show that you need to modify your original design - that's fine. Continue modifying and testing until it works. After verifying operation, demonstrate your circuit to the TA. Lab Report In your lab report include (a) your final schematic, (b) an explanation of the function of each component, and (c) comparison measurements using a DMM that show that your circuit is accurate to within 5%.

Fig: 1