Capacitor-input or choke-input filter?

  • Thread starter Thread starter Pagedown
  • Start date Start date
  • Tags Tags
    Filter
Click For Summary
SUMMARY

The discussion focuses on the differences between capacitor-input and choke-input filters for power supplies, particularly in the context of AC mains connected switching power supplies. It emphasizes that line filters typically incorporate both chokes and capacitors to mitigate switching noise and comply with FCC conducted emissions limits. Additionally, filtering may be necessary between the power source and the switching power supply input to address feed-forward stability issues caused by input noise.

PREREQUISITES
  • Understanding of AC mains power supply systems
  • Knowledge of switching power supply design
  • Familiarity with line filter components, specifically chokes and capacitors
  • Awareness of FCC regulations regarding conducted emissions
NEXT STEPS
  • Research the design principles of capacitor-input filters
  • Explore choke-input filter configurations and their applications
  • Learn about conducted emissions testing and compliance with FCC standards
  • Investigate feed-forward stability issues in switching power supplies
USEFUL FOR

Electrical engineers, power supply designers, and anyone involved in compliance testing for switching power supplies will benefit from this discussion.

Pagedown
Messages
92
Reaction score
0
Capacitor-input or choke-input filter for power supplies?

Whats the difference and when to use them?
 
Engineering news on Phys.org
Pagedown said:
Capacitor-input or choke-input filter for power supplies?

Whats the difference and when to use them?

Can you give some examples?

For AC Mains connected switching power supplies, you will generally have a line filter that has both chokes and caps in it. One of the main tasks of the line filter is to keep the switching noise of the power supply out of the AC Mains, in order to meet conducted emissions limits set by the FCC and other governmental agencies.

Depeding on the power source, you may put filtering between the power source and the input to a switching power supply, to help prevent feed-forward stability issues that could be caused by the input noise.
 

Similar threads

High Pass Filter Working Principle
  • · Replies 15 ·
Replies
15
Views
2K
How Do I Design an EMI Filter for a Converter with Only Voltage and Power Specs?
  • · Replies 8 ·
Replies
8
Views
2K
Line filter, proper LTspice simulation
  • · Replies 15 ·
Replies
15
Views
7K
(Control) Derivative filter and discrete model
  • · Replies 0 ·
Replies
0
Views
2K
Issue with Cancelling ESL for Input Capacitors
  • · Replies 6 ·
Replies
6
Views
2K
Is There an IC for Instant On-Delay Off Circuits?
  • · Replies 7 ·
Replies
7
Views
2K
Sizing an Isolation Transformer for a DC Power Supply
  • · Replies 8 ·
Replies
8
Views
3K
Wavelet transform (CWT and DWT)
  • · Replies 4 ·
Replies
4
Views
3K
Help me breadboard my circuit
  • · Replies 10 ·
Replies
10
Views
3K
Trouble building a Buck Converter
  • · Replies 14 ·
Replies
14
Views
2K