Lab “Temperature Measurement System” + Classwork 3/9/2017

3/9/2017

“Temperature Measurement System”

- We are supposed to design a circuit which is supposed to measure temperature using solderless breadboard, NTC resistor, waveform analog discovery box (or DMM and power supply) with these parameters:

+ Run on 5V

+ Output voltage that varies by at least 0.5 V between 25 and 37 degree celcius

+ Voltage increase as temperature increase

NTC properties:

- Resistance decreases as temperature increase

- Items made from semiconductor

PTC properties:

- Resistance increases as temperature increase

- Items made from metals

We designed the circuit on our whiteboard, picking a 4700 ohm resistor to put into our circuit, which we measured to be 4670 ohms. This should give us value ranging from 1.50 to 2.01 V.

Setup:

Results:

Summary:

Using NTC as our beginning resistor, we get the potential difference of the 4700 ohm resistor to be different for different times. Because resistance decreases when the temperature increases, then current increases, which would make the voltage difference in the 4700 ohm resistors to be higher.

Classwork:

- We started with a quiz because there are a lot of people coming in late.

- Nodal analysis

 Nodal analysis works by calculating the current going out of a point in the circuit. This works wonders because it uses less equations than using KVL/KCL. 

When the voltage source is not connected to ground, we use SUPERNODE! which is more or less similar to the node