122-28176 Parallax Inc, 122-28176 Datasheet - Page 169

• Manufacturer Part Number: 122-28176
• Description: GUIDE STUDENT PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 122-28176

• Accessory Type: Manual
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

Challenge 5-3 : Modifying RC Values
Part A:
Based on the equation for the RC network time constants, what would be the result of
changing R
Part B:
The capacitor is charged using the RC network of R
ACTIVITY #4: OP-AMP BUFFER AND ACTIVE-FILTERS
An operational amplifier (op-amp) is a sophisticated network of transistors that has many
applications when working with analog signals. The uses of op-amps are almost endless
and entire texts have been written around configurations using these devices. We will
explore several of the most popular configurations of op-amps beginning with the buffer.
Additional Part Required:
(1) LM358 Op-Amp
Some important characteristics of the Op-Amp pertinent to our discussion include:
√
√
1. Based on this RC network, how long is required to fully charge the capacitor?
√
√
√
2. If R
√
•
•
•
Calculate the discharge time.
Test your results.
Replace R
Set the sample amount very low.
Cause large step changes in voltage. What occurs? Note that charging only
occurs during that PWM burst, so times will not be accurate.
duration of 255 milliseconds? How long does it need?
When complete, replace R
Extremely high input impedance (theoretically infinite).
Extremely low output impedance (theoretically zero).
The output will be driven in an attempt to drive the inverting input (−) voltage
equal to the non-inverting input (+) voltage.
L
1
to 100 kΩ?
were changed to 1 MΩ, would the capacitor fully charge with a PWM
1
with the 1 MΩ resistor.
1
with the 10 kΩ resistor.
1
(10 kΩ) and C
1
(0.68 µF).