Video: Watch this demo
Description: Use the oscilloscope to show V(t) for a capacitor charging and discharging in an RC circuit.
- capacitor (in video: 1 μF, Vmax = 63 V) in wood block
- resistor (in video: 100 Ω) in wood block
- square wave function generator
- (x1) BNC to banana plug adapter (for scope)
- (x3) banana plug cords
- Place function generator on table where it can be easily accessed by the professor.
- Place scope where it can be easily seen by the class (or by a video camera).
- ***SAFETY CHECK***
- Connect oscilloscope directly to function generator
- Set function generator to 0 dB attenuation, and minimum amplitude.
- Slowly increase function generator amplitude and use scope to measure the voltage.
- When a safe, but appropriate amplitude is reached, LEAVE THE AMPLITUDE AND ATTENUATION AT THESE SETTINGS.
- Disconnect scope from function generator.
- Connect function generator output to resistor and capacitor, all in series.
- Connect scope input across capacitor in parallel.
- Set function generator to square wave, f ≈ 1/(20RC) (in photo, video: f = 530 Hz)
- Set oscilloscope to appropriate Volts per division, sweep ≈ 40RC (in photo: sweep = 0.5 ms).
- Plug in equipment and turn on function generator and scope.
- Turn on all the equipment, and observe the charge/discharge curve. It should be set to the proper settings already.
- If you want, you can adjust the oscilloscope settings and/or the function generator FREQUENCY (please don’t change the amplitude, because it may damage the capacitor and could cause injury!)