Capacitors / How Long can a Capacitor Hold a charge of energy?

Question

How long can the capacitors in small electronic equipment hold a charge after the equipment is turned off? Like small Radios, mp3 players, phones for example. After you turn off a radio, how long will the capacitor hold energy?

Answer 1

I know how capacitors are used in modern equipment of this type. Generally, the answer is in milliseconds. But in the case of flash memory, as used in MP3 players, the unsulated (floating) gate transistors can maintain their charge (thus their memory) for years.

Answer 2

Theoretically? Or realistically? In small instruments such as you're describing, capacitors will bleed off the can charge interior seconds, oftentimes by way of resistance paths interior the circuitry. the place heavy potential materials are used, which includes amplifiers of a few hundred watts, it would desire to take quite a couple of minutes. specific extreme-voltage circuits, on the order of 1000's of volts are designed to be somewhat low-leaking and can conceivably carry a can charge for weeks. lower back to small instruments, there are actually 'great' caps which carry a voltage for hours yet in easy terms at very low cutting-edge stages, performing extra as a battery backup. Now, with extra information, on your cell telephone or Ipod, you're speaking a pair seconds, and there is not something in there that's going to electrocute you besides.

Answer 3

That really depends on the impedance of the circuit around it, and its leakage rating. A really good Cap with nothing to drain off the energy can hold the voltage for a couple of days, maybe weeks, but most caps used in radios might hold their charge for a couple of hours if nothing is draining them.

Answer 4

depends on the size and makeup a car battery is a capacitor