SM transformer audible noise and structure natural frequency
SM transformer audible noise and structure natural frequency
(OP)
Hello,
it's my first posting on the site. My problem is not wholly just electronics, but hopefully someone can provide good advice.
I need to examine audible noise coming from a switch mode transformer component. In theory, the noise is created mainly because of the flux excitation affecting the ferrite core, making it vibrate.
I've been given to understand that a high-freq. transformer, such as this one, normally only creates ultrasonic freq. sound, which naturally doesn't cause noise disturbance. However, there are something called 'transient' and 'burst operation', which cause the noise freq. to come down to human hearing range. These two concepts I don't really understand.
I was first thinking of determining the natural frequency of the transformer structure and measuring the sound amplifying effect of resonance. I am wondering if it is specifically the resonance amplifying the sound that leads to disturbing levels of noise.
Any suggestions how to determine the natural frequency of the transformer's structure? Any ideas how to make the resonance less disturbing? Are there feasible ways to raise the natural frequency higher, close to or over 20kHz? Or how to keep the frequency in the ultrasonic range in this 'burst operation'?
Regards
it's my first posting on the site. My problem is not wholly just electronics, but hopefully someone can provide good advice.
I need to examine audible noise coming from a switch mode transformer component. In theory, the noise is created mainly because of the flux excitation affecting the ferrite core, making it vibrate.
I've been given to understand that a high-freq. transformer, such as this one, normally only creates ultrasonic freq. sound, which naturally doesn't cause noise disturbance. However, there are something called 'transient' and 'burst operation', which cause the noise freq. to come down to human hearing range. These two concepts I don't really understand.
I was first thinking of determining the natural frequency of the transformer structure and measuring the sound amplifying effect of resonance. I am wondering if it is specifically the resonance amplifying the sound that leads to disturbing levels of noise.
Any suggestions how to determine the natural frequency of the transformer's structure? Any ideas how to make the resonance less disturbing? Are there feasible ways to raise the natural frequency higher, close to or over 20kHz? Or how to keep the frequency in the ultrasonic range in this 'burst operation'?
Regards





RE: SM transformer audible noise and structure natural frequency
Dan - Owner

http://www.Hi-TecDesigns.com
RE: SM transformer audible noise and structure natural frequency
"Theory is when you know all and nothing works. Practice is when all works and nobody knows why. In this case we have put together theory and practice: nothing works... and nobody knows why! (Albert Einstein)
RE: SM transformer audible noise and structure natural frequency
RE: SM transformer audible noise and structure natural frequency
I've had power supplies that were quiet as a mouse under full load but would squeal at light loads.
Charlie
Charlie Gill
--www.calibrator.com--