RC Circuit
This demonstration shows charging and discharging characteristics in an RC circuit. Pasco voltage probe with Capstone or Vernier voltage probe with Logger Pro works really well. One can also use Pico Scope as well.
This is what the life sciences and physics majors do in lab in preparing to understand how neurons are modeled as a RC circuit. The engineering majors have been doing cookbook labs, but do something similar, but slightly easier currently. Time permitting, please see the discussion on comparison-based analysis pathway.
Setup:
Set the whiteboard on the lab table. Connect the webcam to the projector and set it up to view the whiteboard from above. Using circuit scribe build the circuit shown in the first presentation.
Do the first demo to show charging and discharging circuit without any measurements.
LED will change from red color in one direction of current flow (saying charging capacitor) and blue in other direction of current flow (say discharging capacitor)
Change out the resistors and capacitors to show how the timing constant changes
Add a POT to the circuit and change the resistance of the circuit to show how the timing constant (RC) plot changes next
Connect the function generator (or Pasco signal generator) to the circuit. Connect Pasco voltage sensor across the resistor.
Set the function generator (or Pasco signal generator) to the 1 Hz square wave range (or 9 Volts amplitude and 1 Hz square wave for Pasco signal generator).
Equipment Needed:
Circuit Scribe Kit
LED Resistor in Circuit Scribe 2-pin connector
Capacitors in Circuit Scribe 2-pin connector
POT Circuit Scribe (potentiometer)
Wires to connect from circuit on dry erase board and measurement tools
Whiteboard
Measurements of Voltage versus Time
Pico Scope
One BNC to Banana Cable
Pico Scope
BK Precision Function Generator
Pasco 850
Voltage probe
Banana Cables with alligator clips
Signal Generator that can be setup in Capstone
Demo Computer with Pasco Capstone and Pico Scope software
Webcam
Notes:
Be sure that all the grounds for the pico scope/Pasco are connected at the same point as the ground for the function generator!
Courses Used In:
PHY 10320
PHY 20435
PHY 30220
Discussion and Polling Questions:
Coming Soon