Cursed circuits #5: capacitance multiplier

5 hours ago

The article explains how to use an operational amplifier (op-amp) to create a circuit that effectively multiplies the capacitance of a capacitor without actually storing more energy, which can be useful for filtering or timing applications.
It details the operation of an ideal op-amp as a voltage follower and applies Ohm's law to analyze current flow through resistors and capacitor charging in the circuit, deriving that the capacitor charges n times slower, where n depends on resistor values, simulating a larger capacitance.
The author notes that while this 'capacitance multiplier' is a neat trick, modern capacitor technology and digital chips often offer better solutions, and includes a challenge for readers to analyze a modified version of the circuit where the capacitor and a resistor are swapped.

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