HW4-2 continued

Now use LTspice to simulate problems 2 and 3 from HW4-1 & 4-2.  You will be using these circuits in your next lab, so SAVE THE FILES so you can change the voltage and resistance values. 

• Problem 2:  Rain Activated Logic (switch)

Use Rain Sensor = 1M ohm when dry and 1k ohm when wet.

Use LM324 op amps with + / - 15V supplies, since that is what we will have in the lab.

• Problem 3: Thermistor Amplifier

Use RT (the thermistor resistance) = 10k ohms at 25 C, 4k ohms when warmer and 14k ohms when cooler.

Use LM324 op amps with + / - 15V supplies, since that is what we will have in the lab.

Turn in:  An explanation of how these circuits WORK.