Input pressure required to produce controller output values

In summary, a direct acting proportional pressure controller with a gain of 3 and a range of 0-40 bar is set to control at 25 bar. When the measured and desired values are equal, the output signal is 60%. The input pressure required to produce controller output values of 10% and 90% can be calculated using the formula: input pressure = (set point - output signal * set point) * (100/gain) + set point. For example, with a set point of 25 bar, an input pressure of 18.3 bar would result in an output signal of 10%, while an input pressure of 29 bar would result in an output signal of 90%.
  • #1
oxon88
176
1

Homework Statement



A direct acting proportional pressure controller has a gain of 3, a range of 0-40 bar and is set to control at 25 bar. When the measured value and the desired value are equal, the output signal is 60%. Determine the input pressure required to produce controller output values of 10% and 90%

Homework Equations


Gain = 100 / % proportional band setting

The Attempt at a Solution

 
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  • #2
Ho oxon,

So far I have read 1. How about providing 2 and 3 as well ? -- if only to avoid being shot into the black hole ...
 
  • #3

Homework Statement



A direct acting proportional pressure controller has a gain of 3, a range of 0-40 bar and is set to control at 25 bar. When the measured value and the desired value are equal, the output signal is 60%. Determine the input pressure required to produce controller output values of 10% and 90%

Homework Equations


Gain = 100 / % proportional band setting
PB = 100/gain

The Attempt at a Solution



PB = 100/3 = 33.33%

33% of input scale (0-40 bar) = 13.33 bar

not sure where to go with this now...
 
  • #4
ok here is what i got...

33.33% of input scale (0 - 40 bar) is 13.33 bar60% of 13.33 bar = 8 bar

50% of 13.33 bar = 6.67 bar

40% of 13.33 bar = 5.332 bar

30% of 13.33 bar = 4 bar0% Output = 25 - 8 = 17 bar

10% Output = 25 – 6.67 = 18.3 bar

90% Output = 25 + 4 = 29 bar

100% Output = 25 + 5.332 = 30.3 bar
 
  • #5
Could it be that the recipe for your proportional controller is as follows (consult your notes or textbook - I'm just guessing)
  • set point is subtracted
  • result is converted to %
  • gain is applied
  • offset is applied
Example: 25 Bar in. 25 bar is subtracted. 0 Bar is 0% 0% is multiplied by 3 add offset 62.5% to get result
Example: 27 Bar in. You see what comes out. Now express the recipe in a formula.
 

FAQ: Input pressure required to produce controller output values

1. What is input pressure?

Input pressure is the amount of force applied to a controller in order to produce a desired output value. It is typically measured in units of pressure, such as pounds per square inch (psi) or kilopascals (kPa).

2. How is input pressure related to controller output values?

The input pressure required to produce controller output values is directly proportional to the desired output value. This means that as the desired output value increases, so does the necessary input pressure.

3. What factors affect the input pressure required for controller output values?

There are several factors that can affect the input pressure required for controller output values. These include the type of controller, the type of input pressure (e.g. air, hydraulic), the size and strength of the controller, and the desired output value.

4. How is input pressure determined for a specific controller?

The input pressure required for a specific controller is determined through experimentation and testing. This involves varying the input pressure and measuring the resulting output values to determine the relationship between the two.

5. Can input pressure be adjusted to achieve a specific controller output value?

Yes, input pressure can be adjusted to achieve a specific controller output value. This is typically done by adjusting the input pressure source (e.g. increasing or decreasing air pressure) or by using a pressure regulator to control the input pressure to the controller.

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