Question

Problem 8 (30 points): Design a complete analog system for the following scenario. Draw the required analog circuitry (you can draw the circuit schematics, or block diagrams, or use a combination). You don't have to compute the specific component values, but state what function each block performs (with relevant equations if applicable) and what the parameters are (or how you would choose them). You have three piezoelectric force sensors; each of them output a voltage that is a linear function of the force applied. For the first and third sensor, the output voltage varies from 0 to 3 V when 0 to 10 N force is applied. The second sensor produces 5 to 10 V when 0 to 20 N force is applied. When the total force sensed by the first two sensors is more than the force sensed by the third sensor, an LED will light up (with a fixed brightness).

Answer 1

FORLE ,İNPUT (0-10N) (0- v) Vi PIEZoELECRIC SENSOK 1 INPUT (0-ON OP AMP GNP INPUT 0-20N)

Here our purpose of whole set up is to use the force as input from 3 available sensors and glow up the led as per requied conditions mentioned in the problem .

**So 1st we take 1st and 2nd sensor , apply forces on them , so that the piezoelectric sensor converts the apllied force pressure into corresponding voltage values in the prescribed range .

** ADDER BLOCK : Then we can take any adder circuit , say op amp based summer circuit that adds up the generated analog voltages and make it a single analog signal at its output . Lets call it Vx

** Then Simultaneously we apply the force on the 3rd sensor at the same time as we have applied the force to the previous two sensors in the set up . Then from 3rd sensor we get output voltage V₃ .

** COMPARATOR BLOCK : Here , we use an op - amp based circuit that simply compares the two different analog signals at the input Vx and V₃ . Thereafter from given condition below after comparator output , we proceed further.

If Vx > V₃ Satisfied , Then WE supply output of comparator as Vcc to the led cicuit connected in the set up

If Vx< V₃ Satisfied , Then WE connect output of comparator to Ground ,So that LED Remains Off.

We can control our Vcc level being fed to led by including a resistor in between LED and op- amp comparator , so that we might get the needed and rated voltage supply for the LED to glow with constant brightness.

Hope i have given suitable model as per need of given case , if you need to disscuss or know more on this , please feel free to comment below , i will be happy to assist you. ******************************************************