Sunday, February 26, 2017

Week 7: Force Sensing Resistors and 7 Segment Displays

Number 1: Force Sensing Resistor
With no load on the force sensing resistor it had 0L resistance or just no connection for resistance for the multimeter then the we squeezed it the more resistance the multimeter read.

Load Resistance
No load 0L
Slightly Pinching 1.1 MOhms
Strongly Pinching 2 MOhms

Number 2: 7 Segment Display
Top led lights up when you ground pin 1
a.)
Video 1: 7 Segment Display explanation 

b.) Below are 2 photos showing the led display showing a 0 and 5. Its showing these by powering the display though the common voltage pin for all the leds and then grounding the cathode end with a resistor for the leds that we need lit up for the 0 or 5.
Display showing a 0
Display showing a 5

Number 3: Display Driver
a.)
Frist Input Combination
Table for First Input Combination.
Inputs High/Low Outputs High/Low
A 0 f 1
B 0 g 1
C 0 a 1
D 1 b 1
c 1
d 1
e 1


Second Input Combination


Table for Second Input Combination.
Inputs High/Low Outputs High/Low
A 0 f 1
B 1 g 1
C 1 a 0
D 0 b 0
c 1
d 1
e 1

We can say that the display driver using internal logic shown in this Truth Table to take the input numbers and output them into the right display for the binary number. as an example we had our 2 input combinations that we tried. The first combination had D high and A,B, and C low which would be binary 8. And to make that 8 it put on all  7 outputs to make the 8. Same with our second combination A and D low, B and C high making binary 6 It put on a certain 5 outputs to make the 6.

INPUTS        OUTPUTS                                                             
D C B A a b c d e f g
Low Low Low Low ON ON ON ON ON ON OFF
Low Low Low High OFF ON ON OFF OFF OFF OFF
Low Low High Low ON ON OFF ON ON OFF ON
Low Low High High ON ON ON ON OFF OFF ON
Low High Low Low OFF ON ON OFF OFF ON ON
Low High Low High ON OFF ON ON OFF ON ON
Low High High Low OFF OFF ON ON ON ON ON
Low High High High ON ON ON OFF OFF OFF OFF
High Low Low Low ON ON ON ON ON ON ON
High Low Low High ON ON ON OFF OFF ON ON
High Low High Low OFF OFF OFF ON ON OFF ON
High Low High High OFF OFF ON ON OFF OFF ON
High High Low Low OFF ON OFF OFF OFF ON ON
High High Low High ON OFF OFF ON OFF ON ON
High High High Low OFF OFF OFF ON ON ON ON
High High High High OFF OFF OFF OFF OFF OFF OFF

b.)
Video 2: Both Display Driver input combinations

Number 4: 555 Timer
a.)
555 Timer Hook up

555 Timer output on Oscilloscope
b.)
Theoretical: Frequency =  1.44/[(Ra + 2Rb)C] =  1.92 H
Duty Cycle = Rb/(Ra+ 2Rb) = 2/5
No, it does not. We are actually getting about half of the theoretical frequency.

c.)
Video 3: Force Sensing Resistor in series with Ra


Number 5: Binary Coded Decimal Counter
a.)
Video 4: BCD input and outputs measured via oscilloscope

Number 6: 7486 XOR gate
a.)
Video 5: XOR gate explanation

b.)
Video 6: XOR gate used in circuit
c.)

Number 7: Entire Circuit Connected Together


Circuit Block Diagram
Video 7: Entire circuit explanation


Number 8: Using AND and OR gates with LED


Video 8: Binary gate combinations


Sunday, February 19, 2017

Week 6: Relays and Temperature Sensors


Operational Amplifiers 
Number 1: Open loop configuration Op-Amp
a.) Non-Inverting
Figure 1. graph for number 1 part a 
Open loop Non-inverting input table
Vin (Volts) Vout (Volts)
-5 -3.7
-4 -3.7
-3 -3.7
-2 -3.7
-1 -3.7
-0.1 -3.7
-0.04 -3.7
0 4.5
0.04 4.5
0.1 4.5
1 4.5
2 4.5
3 4.5
4 4.5
5 4.5


b.) Inverting
Figure 2. graph for number 1 part b 
Open loop Inverting Input table
Vin (Volts) Vout (Volts)
-5 4.5
-4 4.5
-3 4.5
-2 4.5
-1 4.5
-0.1 4.5
-0.04 4.5
0 4.5
0.04 -3.7
0.1 -3.7
1 -3.7
2 -3.7
3 -3.7
4 -3.7
5 -3.7

Number 2: Non-inverting Amplifier
Figure 3. graph for number 2

Non-inverting amplifier table
Vin (Volts) Vout (Volts) Calculated (Volts)
-5 -3.6 -5
-4 -3.6 -5
-3 -3.6 -5
-2 -3.6 -5
-1 -3.1 -3
0 0 0
1 3 3
2 4.2 5
3 4.2 5
4 4.2 5
5 4.2 5



Number 3: Inverting Amplifier
Figure 4. graph for number  3

Inverting amplifier table
Vin (Volts) Vout (Volts) Calculated (Volts)
-5 4.2 5
-4 4.2 5
-3 4.2 5
-2 4 4
-1 2 2
0 0 0
1 -2 -2
2 -3.5 -4
3 -3.5 -5
4 -3.5 -5
5 -3.5 -5



Number 4: How an Op-Amp works? why is the Gain high in open loop but not in inverting/non-inverting?

Relay
Number 1: Resistance measurements between pins
Figure 5. Relay pins

We used the handheld multimeter to measure resistance between the pins of the relay. When measuring between pins 4 and 1, the multimeter was not able to measure any resistance. After switching to measuring pins 3 and 1 the multimeter measured about 1.3 Ohms.

Number 2: Sweeping Voltage on the input pin form 0 to 8 volts.
Figure 6. Relay pins

Shown in Video 1 below, We found that when the voltage is less then about 6 volts the relay is switched to pin 3 but after the voltage is rises about the threshold value of 6 volts the it switches to pin 4. In order for the relay to switch back to pin 3 the voltage needs to fall back below about 2.2 volts.


Video 1: Sweeping voltage across relay


Number 3: Measuring Voltages on output pins after switches.
When applying 5 volts to the input pin and the voltage is below threshold pin 3 measures 5 volts with the handheld multimeter. After the voltage is above threshold pin 4 measure 5 volts.

LED + Relay


Video 2: LED relay circuit


Operational Amplifier
Number 1: Op-Amp with several different sets of resistors.
we used 3 different sets of resistors for the op-amp and change our Vin between 0 and 10 volts.
Set 1 Set 2 set 3
R1: 1kOhm R2: 2kOhm R1:388Ohms R2: 47Ohms R1: 150Ohms R2:100Ohms
Vin: Vout: Vin: Vout: Vin: Vout:
0v 0v 0v 0v 0v 0v
2v 4.46v 2v 2.25v 2v 3.34v
4v 8.54v 4v 4.53v 4v 6.72v
6v 8.54v 6v 6.67v 6v 7.49v
8v 8.54v 8v 8.14v 8v 7.49v
10v 8.54v 10v 8.14v 10v 7.49v

Number 2: Temperature sensor as input to Op-Amp to trigger relay.
Using the temperature sensor to trigger the relay isn't possible. The temperature sensor output voltage doesn't reach the relays threshold voltage so it wouldn't be able to trigger it. However if an op-amp was use in-between the temperature sensor and relay to amplify the temperature sensor's output voltage it to the threshold voltage of the relay the temperature sensor would then be able to trigger the relay.

Number 3: Design a System where the temperature sensor turns on the led.
Video 3: Temperature sensor circuit schematic explanation