How to Choose the Right Capacitor for Smoothing a Full-Wave Rectified Output?

  • Thread starter neduet
  • Start date
  • Tags
    Capacitor
In summary, the conversation discusses the need for a capacitor to smooth out the output waveform of a full-wave rectifier. The amount of ripple and load current must be defined in order to determine the appropriate capacitor size. The option of using a voltage regulator is also mentioned, but the minimum voltage and ripple specifications must still be considered.
  • #1
neduet
64
0
Need capacitor for smoothing?
hello friends

if i have 6 volt peak full-wave rippled output wave form comes from full-wave rectifier. the what rating capacitor (in faraday) i connected with it to make it smooth dc wave.

thanks a lot


frequency is 50hz and 220volt input
and out from rectifier

and my load demands taking current about some mAmp
 
Engineering news on Phys.org
  • #2
There always will be some ripple. You need to define how much ripple you can tolerate. The amount of ripple will also increase with the load current so you also need to define the maximum load current for the ripple specification.
 
  • #3
As an example, with your supply and a 150 ohm load (40 mA), and a 1000 uF capacitor, the ripple would be about 0.8 volts p-p.

You could use a larger capacitor, but the charging current for a bigger capacitor quickly gets very large. Even a 1000 uF capacitor needs about 500 mA charging pulses to charge it.

It is usually better to use a voltage regulator, but you would need at least about 9 volts from the power supply to get 6 volts out and this would have to be filtered.
However, the output of a voltage regulator can be almost perfect DC with only slight ripple and noise visible on an oscilloscope.
 
  • #4
vk6kro said:
It is usually better to use a voltage regulator, but you would need at least about 9 volts from the power supply to get 6 volts out and this would have to be filtered.
However, the output of a voltage regulator can be almost perfect DC with only slight ripple and noise visible on an oscilloscope.

True, but even so you still need to be able to calculate how much ripple you'll have so that you don't go below the minimum voltage the regulator can regulate.
 

1. What is a capacitor?

A capacitor is an electronic component that is used to store and release electrical energy in a circuit. It consists of two conductive plates separated by an insulating material, called a dielectric.

2. Why do I need a capacitor for smoothing?

A capacitor is needed for smoothing in electronic circuits because it helps to filter out any unwanted fluctuations or noise in the voltage, resulting in a more stable and consistent output.

3. How does a capacitor smooth out voltage?

A capacitor smooths out voltage by charging and discharging at a rapid rate. When there is a sudden increase or decrease in voltage, the capacitor absorbs or releases the excess energy, helping to maintain a more constant voltage level.

4. What types of capacitors are suitable for smoothing?

There are various types of capacitors that can be used for smoothing, such as ceramic, electrolytic, and film capacitors. The type and size of capacitor needed will depend on the specific electronic circuit and its requirements.

5. Can I use a larger capacitor for better smoothing?

Using a larger capacitor may not necessarily result in better smoothing. The size of the capacitor needed for a circuit depends on factors such as the amount of current and frequency of the voltage fluctuations. It is important to choose the right size and type of capacitor for optimal smoothing in a circuit.

Similar threads

  • Electrical Engineering
Replies
10
Views
2K
  • Electrical Engineering
Replies
7
Views
4K
  • Electrical Engineering
2
Replies
63
Views
5K
  • Electrical Engineering
Replies
5
Views
2K
  • Electrical Engineering
Replies
7
Views
3K
  • Electrical Engineering
Replies
1
Views
2K
Replies
9
Views
1K
  • Electrical Engineering
Replies
2
Views
2K
Replies
19
Views
2K
  • Electrical Engineering
Replies
1
Views
2K
Back
Top