AC Circuits

Driven RLC Circuit

rlc circuit

What It Shows

The amplitudes and relative phases of the voltages across the individual elements of a series RLC circuit varies with the frequency of the driving voltage. The voltages of the three elements plus the driver are plotted simultaneously on an...

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OHP RLC Circuit

What It Shows

The current in a circuit consisting of a capacitor, inductor, and resistor will oscillate back and forth as the capacitor charges and discharges.

How It Works

The circuit layout is shown in the figure below. Initially the knife switch links the capacitor to the battery. Switching to complete the LRC circuit allows the capacitor to discharge. The current I in the circuit increases, as does the magneic field B inside the inductor. When the capacitor charge is zero, I and B are a maximum (the energy of the circuit is now stored in the inductor). As the...

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RC Time Constant

Charging and discharging of a 10µF capacitor with variable time constant.

What it shows:

The growth and decay of current in an RC circuit with a time constant chosen so that the charge and discharge is visible in real time.

How it works:

By choosing the values of resistance and capacitance, a time constant can be selected with a value in seconds. The time constant τ is given by

τ = RC

To obtain useful values, we chose three resistors 100K, 200K and 400K in series with a 10µF capacitor, giving time constants of...

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RL Time Constant

What it shows:

The growth and decay of current in an RL circuit with a time constant visible in real time.

How it works:

By choosing the values of resistance and inductance, a time constant can be selected with a value in seconds. The time constant τ is given by

τ = L/R

We chose two resistance values, 4.7K and 10K coupled with a 45kH UNILAB 1 induction coil giving time constants of 9.5sec and 4.5sec respectively.

The circuit is set out on a 1.0 × 0.5m plywood board. The actual...

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