AC Basics Capacitors and Inductors in Parallel

[@wolfganghiesmayr8745]

Hello, dear Sir This video is very useful. Great explaination

[@pboston6RR]

Thanks. This helps a little when I’m trying to stop the signal reflectance in model railroad control systems. There are places along the track where the signal meets the reflected signal and we have a result of NO signal.

[@bradleyr4451]

Thanks these are so well done. at 19:00 this is the reality of digital circuits at high speed, used to test TTL circuits all day and you look at pins of the ICs and what should be a square wave is like what you show, because every circuit line has L/C/R in there so this is a very important concept.

[@BharatGyanee]

U r true teacher of electronic. My best wishes from India .

[@jboy4real]

Kindly do a practical video on EMI filter for ac mains

[@leenkaur9528]

brilliant have no words to say ur great

[@lauralhardy5450]

Capacitive reactance does not linearly decrease with frequency. You need to correct that graph.

[@carultch]

On a double-log plot, the graph will be a straight line.

[@lauralhardy5450]

@@carultch Not here, I do not see one

[@rajeevkchauhan]

Pl correct capacitive reactance variation with frequency.

[@shuvra4352]

I found this circuit in bike indicator light, which alternately turn on and off the indicator light. But in bike it uses DC voltage, so how it's work there?

[@carultch]

It's probably a 555 timer. There's a charge/discharge cycle of a resistor and a capacitor, that is used for establishing the clock signal. The 555 timer picks up on the time it takes for the capacitor to charge and discharge to certain fractions of the initial charging, in order to produce an output signal that cycles on and off.

[@anton_c8gur]

my head hurts

[@bradleyr4451]

Would you say this is like a car's suspension with a spring and shock absorber? they are given input waves that they resist but at other wave rates they are passive?

[@carultch]

Yes. It's a very similar concept, where the mass/spring/damper all do calculus on the position of the car as a function of time, as they respond to disturbances. This sets up a differential equation that governs the response of the car. The spring reacts to the instantaneous vertical position, the damper reacts to the vertical velocity, and the mass responds with an acceleration. Relating it to electricity, the capacitor is analogous to the spring, the resistor is analogous to the damper, and the inductor is analogous to the mass. This means that the arrangement of capacitors, inductors and resistors, sets up a differential equation that relates the source to the load. Using the concept of impedance, and complex algebra, we're able to simplify the math from solving differential equations to solving algebraic equations.

[@bradleyr4451]

@@carultch yes thank you, Id love to see/learn the calculus of this. but I thought the Cap is like the damper, inductor like the spring and resistor like the load/mass? Inductance is the force that resists a change in current? Capicatance the force resisting a change in voltage? the shock absorber resists in one direction far more than the other

[@carultch]

​@@bradleyr4451 One factor that probably gets in the way of seeing this analogy, is the fact that electrical engineers think in terms of current, instead of charge. By contrast, the mechanical engineers start with position, and differentiate to determine velocity and acceleration. EE's start in the middle, differentiate to find what an inductor does, and integrate to find what a capacitor does. When learning kinematics, you start at the most integrated end of the concepts, and differentiate to find everything else. Think in terms of charge on the capacitor, and the analogy will line up much better. On top of this, capacitance isn't directly analogous to the spring stiffness, but rather its reciprocal: the spring flexibility. For mechanics, the derivatives follow the following pattern: Position vs time = original function Velocity vs time = derivative Acceleration vs time = 2nd derivative For electronics, we usually think of it this way: Charge = time integral of current Current = original function Current ramp rate that an inductor acts up on = time derivative of current But instead, if you think of it this way, it will line up better with a mechanical analogy: Charge on a capacitor = original function Current = first derivative Current ramp rate for an inductor = 2nd derivative

[@carultch]

@@bradleyr4451 The damper is analogous to the resistor, because it takes energy out of the mechanical domain, and produces thermal energy. The spring is analogous to the capacitor, because it stores energy as a function of its static configuration: the configuration of charges on the capacitor, and the configuration of metal atoms in the spring. These are both forms of potential energy, that only depend on what you can determine at a static snapshot in time. The mass of the car stores energy of motion, while the inductor stores energy in its magnetic field. If you pause everything in motion, and lose the information about current and velocity, there will not be enough information to determine the KE stored in the mass, or the energy stored in the inductor. These are both forms of energy that are based on motion, rather than position/configuration. In any event, both the energy of motion, and the energy of position, can be returned to the system reversibly. The heat energy that the resistor and damper generate, by contrast, cannot. This is why the analogy lines up this way.

[@carultch]

@@bradleyr4451 Here's why the components have the analogous relationships I've assigned. Capacitors and springs both store energy in a potential energy form; a form that only depends on configuration of charges and atoms. You can take a snapshot in time, and you'll have all the information to know the potential energy stored in either of these components. Inductors and masses both store energy in a kinetic form; a form that depends on the state of motion of the charges and atoms. A snapshot in time won't tell you enough information to find the energy stored in these forms. Resistors and dampers do not store energy, instead they dissipate energy into the form of heat. The energy these components absorb, leaves the mechanical domain (for the suspension system) and leaves the electrical domain (for the circuit) permanently.