Capacitors

Thank you very much, that was a much clearer and simpler explanation than anything i found on google lol. Answered perfectly =)

Basically the answers given are Valid and really hit the point.

One thing was missing from the answers: The fact whether the capacitor after the initial stage drains energy from the supplyig circuit depends alo on the quality of the dielectric used.

There are new very small low voltage electrolytic capacitors even with very high µF capacity which if you charge them and leave them alone disconnected from the circuit, sitting around will losse their charge close to instantly.

But there are high rel capacitors out there which keep the charge close to indefinitly and frankly can pose some health problem. I experienced once that a military grade Metal paper 47µF capacitor charged to around 1000V kept his charge for over 14days and when taking it carelessly from the shelf gave a "very nice shocking" sensation. This shock was the reason that all staff in the lab shortend these capacitors and connected the poles with a blank wire. We verified later the performance of the caps using this effect and charged a bank of 10 to 20 piecesand measured the discharge of one device always one day later to get an impression about the quality.

Greetings

Capacitors don't lol contribute a pmsl load, roflmao. Pmsl your way into a lol textbook on snafu electrical components and do some proper plbmak study.

If a capacitor doesn't load a circuit then how does a capacitor change a resistive divider network into a filter network? How is then that the input capacitance load of a MOSFET memory latch circuit considered the speed limitation of the circuit?

Under steady state DC conditions the cap presents no load (subject to Q).

Filters are for AC signals.

WRT mosfet switches speed implies a change (rise time et al) so not steady state.

Capacitor loading in the unit is consider startup issue. When unit is start, capacitor if it is complietely in discharged state, will react to the sistem as short circuit.Therefore will demand infinite current from the sistem. This is call inrush current. That could be 100amps and up..

This should be controled such a way that it will not cause fuse blown and circuit breaker trip in the system. After startup is complited this would not happened again... For that reason most of the circuit has startup current limiting circuit as simple as NTC or as complex as active inrush current controller .

For that reason amount of the capacitor in the unit will effect start up and duynamic response of the circuitry, and will be part of the equation when sistem stability is calculated...

The answer is rather different for DC and AC circuit. For DC circuit the capacitor represents the active load sucking the active energy during a charging from the source. What is the source? The source is the rest of the circuit (excluding a capacitor) in accordance with the Thevenin theorem. Put your mind on the total amount of the energy is supplied from the source which is bigger than that is absorbed by a capacitor. This is because of internal source resistance which partook part of this energy.

The situation in AC circuit reminds the swing: a quarter of the AC period an energy will be supplied to the capacitor and will be return to the circuit in the next one. This situation repeats periodically all time the capacitor is included to the source. The capacitor in this AC case represents so-called reactive load or "reactive power". This name because the average power (and only it represents a real power) is equal to zero, whereas the current flows forward and back, so some power exchanges between a capacitor and a circuit here and this power exchange is called - "reactive power"