Capacitors/inductors have memory?

[dgamma3]

Hello, my textbook states that "Circuits that contain capacitors and/or inductors have memory". In what sense do they have memory?
my understanding of memory, is retaining value. how do inductors/capacitors retain value?

thanks
daniel

 

[jaydnul]

An inductor stores energy in its magnetic field, a capacitor stores energy in its electric field. "Memory" might just be a poor choice of words although I'd guess you could extract some information about the circuit from the amount of energy stored at a given moment.

 

[Born2bwire]

A capacitor can retain memory of a voltage and an inductor a memory of a current in a sense. For example, an integrator can be built using an opamp and a capacitor. The capacitor acts as a memory of the integral and holds the output voltage when the input goes to null. The integtal is obtained by building up the voltage across the cap. You have to have a reset circuit to drain the cap to start the integration afresh. An inductor could do something similar for a current as it strives to maintain a current through it but it is not as effective due to an inductor's resistive losses draining the current. But this idea of memory should be cautiously applied to certain situations.

 

[CWatters]

The voltage drop across a resistor at any instant in time depends on the current at that time. The voltage drop across a capacitor at any instant in time depends on the charge (aka current) that flowed into it in the past. Memory is a reasonable word to describe a parameter that depend on past data.

 

[sardar]

I can confirm that capacitors and inductors do have a form of memory in the context of circuits. This is because these components have the ability to store electric charge or energy, which can be released at a later time. In electrical engineering, this is known as energy storage.

Capacitors store energy in an electric field between two conductive plates, while inductors store energy in a magnetic field created by a current passing through a coil. When the circuit is turned off, these components can hold onto this stored energy and release it back into the circuit when needed.

This ability to store and release energy is what gives capacitors and inductors their "memory." They can remember the energy that was stored in them and release it at a later time, making them useful in many electronic devices and circuits.

I hope this explanation helps clarify the concept of memory in relation to capacitors and inductors. Feel free to ask any further questions or seek additional resources for a deeper understanding.