What is the function of a resistor in a capacitor circuit?

Question

Can you charge a capacitor without a resistor in the circuit? What is the resistor there for?

Answer 1

To protect the capacitor from a high current. I=U/R where U is the voltage and R is teh resistor's rezitance measured in ohm. So a high resistance will decrease the current.

Answer 2

You don't need a resistor to charge a capacitor. A capacitor is like a battery you just sort of fill it up provided that the voltage you are using already matches what a capacitor can use. Say the capacitor is rated for 3 volts and you connect 3 volts to it, then you wouldn't need a resistor.

The resistor is there to limit voltage and/or current. Lets say you have 5 volts and your capacitor can only take 2 volts. If you put the correct resistor in the circuit you can get the resistor to take 3 of those volts and leave 2 volts left over for the capacitor.

The resistor is limits the current. As in how fast the electrical flow past a certain point. Current is given by the voltage / resistance. So by reducing the voltage across the capacitor reduces how much current the capacitor will see at any given time. Devices have a limit of the voltage and current they can stand before they blow up or melt down.

Answer 3

The Capacitor can hold a charge, usually DC (Direct Current). AC (Alternating Current) changes polarity +/- then -/+ so it hard for it to charge the Capacitor. Usually the capacitor used as a filter with AC to keep DC out of the circuit. The Resistor can be used as a Bleeder Resistor to drain the capacitor when the power off to prevent being a shock hazard.
Been a long time I mess with this stuff, but, this some of the general concept.

Answer 4

I assume that you are asking the resistor in series with capacitor.
Usually, there is no series resistor for the (small power supply )filter capacitor because internal resistance of the transformer will do the current limiting function.
May be the circuit you are asking is timing circuit which will slow down the rising of capacitor voltage to reach preset level.

Hope this will help.

Answer 5

in many circuits you will come across it as a standard specification. it is the RC timining or inverse RC timing coefficient. it contols the time od charge and discharge in dc and in AC in combnation to the capacitor it acts as a filter depending on the series parallel conection to it.
say you have a completely charged capacitor and you discharge it through a resistor you get a graph.
now for the same capacitor if you repeat the procedure with a larger value of resistor you will immidietly realise the longer time taken and smoother transient .

Answer 6

would be nice if you have a real schematic, and some idea of what the connector is going to, and what the TSOP thing is. And the lead orientation of the transistor. as it is drawn, without that additional information, i can't make any sense out of it. .