0
in ic 7805 their is two capacitor is used one of them is used for the settling/transient time and another is used to provide inductive effect....
Wiki User
∙ 12y ago
Add your answer:
Earn +20 pts
What is the main use of ic 7812?
Here is circuit 9V power supply regulator with battery 12V backup system. Use IC 7812 and 7805 control voltage output by R3 1K output 9V 1A max. This is a 9V power supply which will work even on power failure. It uses a rechargeable battery and regulators. A transformer with 15-0-15 AC volts output is required. In the first regulator U1 the output is lifted up by 1.4V and in the second regulator U2 by a resistor divider. In the second regulator the voltage across resistor R3 is 5V, so the current is 5V / 1K = 5mA this adds to the quiescent current of 5mA from the regulators ground terminal and flows into the resistors R1 and R2 in parallel which form 404 ohms, 10mA thru 404 ohms is 4V. So the output will be 5 + 4 = 9V. Note that the charge and discharge paths of the battery are separated with diodes.
What can happen if you use a 440 vac capacitor instead of a 370 vac?
You can always use a higher voltage rated capacitor, it will probably just last a little longer.
Which voltage regulator is best to use lm140 or lm78xx?
A: Neither these are fixed regulator and the lm140 is ancient. My choice for any regulator is LM117 since i can get 1.25 volts to over 30 volts with two resistor,
How a can capacitor smoothen or reduce the ripple of the voltage produce by the rectifier?
Rectifiers will not give a smooth DC voltage. There are ripples in the voltage given the rectifier. So in order to smoothen the voltage we use capacitor in parallel to the rectifier output. Now lets see how the capacitor smoothen the voltage that is coming from a rectifier...... Capacitor blocks DC and allows AC...... If we take the voltage that is coming from the rectifier it has some ripples in addition to DC, these ripples can be divided in to sinusoidal wave forms ( fictitious )according to the Fourier series. So the rippled DC now divided ( fictitious ) in to a pure DC and sinusoidal AC wave forms having the frequency that is multiples of ripple frequency. Now the DC current will not pass through the capacitor as the capacitor blocks DC. But the AC will pass through it i.e the ripple wave forms that are divided ( fictitious ) in to sinusoidal AC wave forms will pass through the capacitor. So only DC current enters in to the load, which will produce a pure DC voltage drop across the load. In this manner the capacitor smoothens the voltage.
What is the use of capacitor in touch operated system?
Capacitors are used on touch screen technology. mystery of using capacitor in touch screen is the working principle of capacitor . when you touch the screen the distance between two plates inside screen will change(by pressing) and this will cause the change in capacitance and hence in voltage and this signal fed to processor to process it. and that behind the use of capacitor in touch screen.
What are the Advantages and disadvantages of IC voltage regulator?
IC voltage regulator performs better than any analog voltage regulator. Some IC regulators IC no. are given below- Positive IC voltage regulator- 78xx Negative IC voltage regulator-79xx where xx varies according to the use of ICs raring. as 7805 gives the positive 5 Volt & 7905 gives the negative 5 volt.
Can you use a high voltage capacitor on a low voltage battery?
Yes. You just don't want to exceed the voltage rating of the capacitor.
Why you use capacitors before and after regulator ICs in a voltage supply circuit?
The capacitor before the IC is filtering the output of the rectifier, so that the minimum voltage dip between diode conduction cycles is greater than the minimum voltage the IC requires. The capacitor after the IC is stabilizing the IC, by preventing it from oscillating, and responding to quick changes in load faster than the IC can.
How voltage regulator on motherboard work?
There are several. Some use an A/C inverter. The DC is put through an oscillator using a coil. A switching transistor then charges a capacitor, while a dedicated power supply chip controls the mark/space ratio of the pulses, to regulate the voltage and current. Simpler devices, like the 7805, are power transistors which have a zener base reference, to control the voltage passed by the transistor. These just add resistance to a higher voltage and reduce it to a lower one. They run quite hot and have heat sinks.
What type of capacitor use to stabilize a 12 volt car when the voltage drops and how to wire?
"What type of capacitor use to stabilize a 12 volt car when the voltage drops and how to wire?"
Why use capacitors on fan motors?
capacitor stores charge ,so we use capacitor in fan for continuous voltage supply.
Why cant capacitor filter connected in series to load?
in output is pulsetting voltage remove the pulses to use the capacitor this passes the pure voltage to the load
How do you make a circuit that will convert 12 volts DC to variable voltage?
There are a couple of ways. The easiest one, albeit the least efficient, is to just stick a potentiometer in the +12 line coming out of the supply. The best way is to use an LM317 adjustable voltage regulator. You always lose a couple volts in a regulator, so you can only get 10v or so out of a regulated supply. I've also seen how you can "turn up" a 7800-series regulator's voltage by feeding voltage into the reference terminal. This makes sense--the regulator really doesn't care how much voltage it puts out, it only cares about putting out 5v or whatever more than the reference voltage. The problem with doing it this way is you can only go so low, namely to the voltage written on the device's package--if you used a 7805, you've got a 5v-10v supply.
When might it be necessary to use a 2 µF polyester capacitor rather than a 2 µF electrolytic capacitor?
when high voltages are present because the voltage rating of polyester (polyethylene terephthalate) capacitor is high as well as electrolytic capacitor will destroy if the voltage increases from nominal voltage and cause short circuit conditions.
Is IC 7805 used as constant current source?
yes you can use IC 7805 as constant current source, Please see the data sheet application for LM7805 in typical application but you must know what the temp that IC 7805 is working at becomes the output voltage drift is - 0.8 mV/C at Vin =10 volt.
Is a potentiometer and voltage regulator the same thing?
No. A potentiometer is a variable resistor that allows you to set a voltage ratio or to adjust a resistance in a circuit. A voltage regulator, on the other hand, is a device that responds to changes in load, making automatic correction of output voltage. If you increase the load on a potentiometer, the output voltage will change, but not so (within limits) for a voltage regulator. However, you can use a potentiometer in a voltage regulator to make the output adjustable.
What is the use of diodes in doubler voltage?
A: The purpose it to block the capacitor from discharging to the source
