switching toroids heating up too much.

muddasirwaheedmalik · 4th December 2011, 10:45 AM

hi there.

i am using CLASS--D lanzar vibe 3.5KD amp 700 winto 4 ohm for powering my 12 inh 20 hz tuned subwoofer crossed over at 50 Hz with a 20 Hz subsonic filter.

Now this is a car amp and i am using in HT so it is powered with Lambda EWS-1500 -12 , 1500 watt , 12 V SMPS, 125 A and sure its a big thing.

Now even without no signall at the amp input, the switching transformers get very hot and so do the filtering chokes but the FETs are not at all hot. My question is could it be due to EMI present in SMPS ????? is it a bad combination.??

richie00boy · 4th December 2011, 11:32 AM

Is the load connected while you are doing this test?

darkfenriz · 4th December 2011, 11:35 AM

How hot?
30-40 degrees celsius over ambient can be considered normal by some designers.

muddasirwaheedmalik · 4th December 2011, 02:12 PM

No. even with load removed its get hot. like 30-40. but not on clean car DC supply i remmebr. but strangely the power FET and heat sink are cool cucumber on no load. its just the TWO toroid switiching transformers and filtering toroid coils. BTW its a switching class D MOSFET regulated AMP. My sixth sense is pointing 100-200KHZ pulses getting the way in torioids and their cancellation causing heating up of ferrites?????

nigelwright7557 · 5th December 2011, 01:33 AM

I use a t106-2 core with 18SWG enammelled copepr wire and it barely gets warm.
I originally used power cores but these got to 120 degrees !!!

4th December 2011, 10:45 AM	#1
muddasirwaheedmalik diyAudio Member Join Date: Jul 2010	switching toroids heating up too much. hi there. i am using CLASS--D lanzar vibe 3.5KD amp 700 winto 4 ohm for powering my 12 inh 20 hz tuned subwoofer crossed over at 50 Hz with a 20 Hz subsonic filter. Now this is a car amp and i am using in HT so it is powered with Lambda EWS-1500 -12 , 1500 watt , 12 V SMPS, 125 A and sure its a big thing. Now even without no signall at the amp input, the switching transformers get very hot and so do the filtering chokes but the FETs are not at all hot. My question is could it be due to EMI present in SMPS ????? is it a bad combination.??

4th December 2011, 11:32 AM	#2
richie00boy Did it Himself diyAudio Member Join Date: Nov 2003 Location: Gloucestershire, England, UK	Is the load connected while you are doing this test? __________________ www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, kits and more

5th December 2011, 01:33 AM	#5
nigelwright7557 diyAudio Member Join Date: Apr 2008 Location: Carlisle, England	I use a t106-2 core with 18SWG enammelled copepr wire and it barely gets warm. I originally used power cores but these got to 120 degrees !!! __________________ http://www.murtonpikesystems.co.uk PCBCAD40 pcb design software.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
An amplifier without any heating	badboy6120	Class D	21	13th August 2011 09:58 PM
heating of mosfets	takku	Solid State	3	2nd April 2010 08:31 PM
Heating the circuit?	lumanauw	Solid State	2	31st December 2006 05:44 AM
heating	kathodyne	Tubes / Valves	3	2nd September 2005 12:49 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

4th December 2011, 11:35 AM	#3
darkfenriz diyAudio Member Join Date: Jun 2004 Location: Warsaw	How hot? 30-40 degrees celsius over ambient can be considered normal by some designers.

4th December 2011, 02:12 PM	#4
muddasirwaheedmalik diyAudio Member Join Date: Jul 2010	No. even with load removed its get hot. like 30-40. but not on clean car DC supply i remmebr. but strangely the power FET and heat sink are cool cucumber on no load. its just the TWO toroid switiching transformers and filtering toroid coils. BTW its a switching class D MOSFET regulated AMP. My sixth sense is pointing 100-200KHZ pulses getting the way in torioids and their cancellation causing heating up of ferrites?????

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read