fabrication

5

Spring 2020

ECET 296

Electronic System Design

TAP-5 FINAL

GROUP NUMBER: _____

Students Names	Student ID
Fatima Malaki	82696

S	Topic	Maximum Points	Earned Points
1	Hand Calculations	40%
2	Build Circuit on the breadboard in Tinkercad and simulate it	40%
3	Circuit Analysis	20%
4	Bonus	10%
	Total	110%

NOTES:

Design comparator similar to schematic bellow. Comparator will have two GREEN LEDs connected in series on the output. Source is battery of 9V. Voltage on inverting input V- should be 3.5V. Sensor will not anymore be Light Depending Resistor, instead of LDR we will use photodiode.

1. Hand Calculations (40points / 10each)

a) write down one paragraph about photodiode

b) Values of resistors to deliver 3,5V on the inverting input V-?

(you can use resistors R2 and R3 as reference)

R2 = 15.71 KΩ

R3=10 KΩ

c) Prove mathematically that your resistors can deliver 3,5V on inverting input V-.

V- = Vin x R3/(R2+R3) so 3.5 = 9 x R3/(10k +R3) so R3=7K/7 =15.71 kΩ

So V- = 9 10k/(10k+15.71k) = 3.5 V

d) Calculate minimum value of resistor to not burn the GREEN LEDs?

2. Build Circuit on the breadboard in Tinkercad and simulate it. (40points )

a) Circuit on the Breadboard (20points)

b) Connect two voltmeters on V- and V+ (10points)

c) Simulate LEDs in on and off states (10points)

LED ON

LED OFF

3. Circuit Analysis (20 points/ 10each)

a) Why value of the resistors used to deliver 3,5V on the inverting input V- are in kOhms. We can get 3,5V on the inverting input using much smaller values (example using resistors of few Ohms)

b) How voltage in noninverting input V+ changes compared to dark and light conditions?

4. Bonus (10points/ 5 each)

a) Can we have 2 White LEDs connected in series on the output?

Yes

b) Why?

White color need minimum forward voltage= 3.4 so 2 white led need 6.8V and in our circuit output voltage = 9 volt so we can have 2 white LEDs connected in series on the output

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