Aan Posted January 12, 2007 Report Share Posted January 12, 2007 What type of inductors typically used in LC filter, is it toroidal or solenoid ?Thanks. Quote Link to comment Share on other sites More sharing options...
AN920 Posted January 13, 2007 Report Share Posted January 13, 2007 There's LC filters of all kinds, low/high frequency and of various power levels. For example, you won't use toroid at very high frequencies because of the losses. Each applicarion will require its own selection. Quote Link to comment Share on other sites More sharing options...
indulis Posted January 13, 2007 Report Share Posted January 13, 2007 The amount of current and frequency has a lot to do with selecting the proper core shape (for cross sectional area) and material (for Bsat). How much ripple current can yo live with?For example, you won't use toroid at very high frequencies because of the losses.You can get toriods in soft ferrite material now and the "Cool-Mu" toriods from Magnetics work very well in SMPS. Quote Link to comment Share on other sites More sharing options...
AN920 Posted January 13, 2007 Report Share Posted January 13, 2007 Maybe we should define "very high frequency" Quote Link to comment Share on other sites More sharing options...
Aan Posted January 13, 2007 Author Report Share Posted January 13, 2007 I recommend a search on google for the type of filter you need.....I have searched google and have not yet find any good site to use as reference to build LC filter..There's LC filters of all kinds, low/high frequency and of various power levels. For example, you won't use toroid at very high frequencies because of the losses. Each applicarion will require its own selection.I build a DC-AC converter with class D amplifier with frequency carrier of 10kHz.The amount of current and frequency has a lot to do with selecting the proper core shape (for cross sectional area) and material (for Bsat). How much ripple current can yo live with?0.1mAmp..how much ripple current typically find in any design of LC filter ? Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 13, 2007 Report Share Posted January 13, 2007 The 10kHz noise will drive you nuts. Use a carrier frequency above 20kHz so it won't be heard. Quote Link to comment Share on other sites More sharing options...
prateeksikka Posted January 18, 2007 Report Share Posted January 18, 2007 i dont think frequency is the criteria .it is just the question of current carrying capability. Quote Link to comment Share on other sites More sharing options...
indulis Posted January 18, 2007 Report Share Posted January 18, 2007 Frequency does matter. In a power application for example... take a simple buck converter, Vout/Vin will tell you the ~ duty cycle, but the frequency will determine the "off time" (flywheel period during which current is flowing out of the inductor) of the converter. That "off time" plays a role in the inductor value and will determine the ripple current amplitude. A properly sized "power inductor" that works at 100KHz will not work at 1KHz... it will saturate. Frequency will determine max flux excursion and hence, max current capability. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.