Homework 8 – temperature sensor
Objectives
1. Build, test, and troubleshoot a temperature sensor circuit using Multisim.
2. Design a temperature sensor circuit that detects temperatures higher than the
specified value.
3. Hardwire the temperature sensor circuit of objective 1 and compare the
measurements of the hardwired circuit with the measurements obtained in
Multisim.
Example 1
In this circuit we got a demonstration of the inverting properties of the amplifier.
V ref is roughly half of the V0.
Example 2
If we change the values of input voltage, we can get the inverted results of output
voltage. For example, if Vin is more than Vref, we got the positive output voltage.
However, if Vin is less than Vref (less than 7.5), our output voltage value changes
to negative.
Example 3
We took a potentiometer instead of R2 to assemble the circuit below. By the
formula
Vref = V1*(R1/R1+R2)
we were able to establish the needed value of R2, so the reference voltage on R2
would take a value of 3.5 V. The resulting R2 should have resistance of
approximately 32kOhms.
Example 4
When the single source of voltage is used, if the Vref is more than Vi, we get the
V0 value closer to zero, and in the opposite case, we have the value close to the value
of the source.
Example 5
The scheme was a simulator of the operation of temperature sensor. As a result, in
certain conditions, an alarm in the form of LED will lighten.
By assembling the circuit as in the scheme, we got the values of Vref and Vi
exact the same, 238mV.