RC High-Pass Filter |
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Active RC Low-Pass Filter |
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Kletzing's High-Pass Filter Circuit for Clicker Question |
Clicker Question for Kletzing's High-Pass Filter |
RL Low-Pass Filter |
RL High-Pass Filter |
RL High-Pass Filter with light bulb indicator |
Code Number: 5L30.30
Demo Title: Circuit Filters
Condition: Excellent
Principle: AC Circuits
Area of Study: Electricity & Magnetism
Equipment:
Capacitance Box, Resistor Box (Carbon Resistors), Wave Generator (Wavetek), Oscilloscope, Frequency Counter (if desired), and Homemade Inductors, 9 Volt Batteries, Passive and Active High and Low Pass Filter Circuits.
Procedure:
Passive and Active High-Pass and Low-Pass filters are available for demonstrations as shown. You will need to connect two 9 Volt batteries to each Active filter circuit.
This circuit is used to demo Craig Kletzing's clicker question.
An RL circuit can also be used as either a high pass or a low pass filter depending on which component you take the output from. Take the output from across the resistor and you will have a low-pass filter. Take the output from across the inductor and you will have a high-pass filter. The frequency range can sweep from 0 to 13 MHz with the manual control on the wave generator. The resistor in our circuit is set from 1000 ohms. As you sweep the frequency range on the high pass filter, there will be several places in the range where the frequencies will pass freely (Around 6 MHz. and from 10 to 13 MHz).
This RL circuit is able to take enough voltage and current to light the small incandescent bulb with is placed across the inductor, making this a high-pass filter.
References:
- Erik Zavrel, Eric Sharpsteen, "Introducing Filters and Amplifiers Using a Two-Channel Light Organ", TPT, Vol. 53, #8, Nov. 2015, p. 478.
- Yaakov Kraftmakher, "1.15 Electrical Filters", Experiments and Demonstrations in Physics, ISBN 981-256-602-3, p. 58.