I know this is another "I'm new to class-d/smps" thread but I'm hoping to get some answers...
I've been looking at a ESP design Project 89 : Switchmode PSU for car audio and want to build it or something similar.
I know there is a lot of information out there to read but it's all a bit overwhelming when you don't know where to start.
I've also found that I learn better by asking specific questions on a topic.
So here goes...
What I've got / can get so far is:
SG3525 (on order)
IRF540 x 4
ferrite cores x 2 : Outsid diam:39mm, inside diam: 20mm , thickness: 11mm.
Copper Wire: 1mm and 2mm thick.
My first question is, based on the core and wiring, how do I calculate the best switching frequency?
I've been looking at a ESP design Project 89 : Switchmode PSU for car audio and want to build it or something similar.
I know there is a lot of information out there to read but it's all a bit overwhelming when you don't know where to start.
I've also found that I learn better by asking specific questions on a topic.
So here goes...
What I've got / can get so far is:
SG3525 (on order)
IRF540 x 4
ferrite cores x 2 : Outsid diam:39mm, inside diam: 20mm , thickness: 11mm.
Copper Wire: 1mm and 2mm thick.
My first question is, based on the core and wiring, how do I calculate the best switching frequency?
you can use for Sg3525 30.000 Hz and you can make for it 2x5 turn for primer, but you must calculate for secondary voltage, for example, input 12 volt and output 2x48 volt, primer turns 2x5 turns and 2x20 turns for secondary, ý made and it is great,but you must use 4mm for primer and 1mm for secondary
Adnancoskun said:
you can always double up the strands on the primary to attain higher current carrying capacity.
sure,
if your output voltage is higher than input voltage, primery current high more than secondary current, is not it? so your primer wire must be thick more than secondary wire, is it ok? ý told before, if your input voltage 12 volts and output voltage is 2x48 volt and if you want use 1mm thick for secondary so you must use 4mm for primer, becouse your output voltage is high more secondary voltage,
thanks;
if your output voltage is higher than input voltage, primery current high more than secondary current, is not it? so your primer wire must be thick more than secondary wire, is it ok? ý told before, if your input voltage 12 volts and output voltage is 2x48 volt and if you want use 1mm thick for secondary so you must use 4mm for primer, becouse your output voltage is high more secondary voltage,
thanks;
Hello, Wynand.
Nice to hear that you found my article at ESP useful.
In order to calculate the transformer turns, you first need to know what is the cross-sectional area of it and use the flux density formula to get the number of turns for a given frequency and flux density.
In order to make your life easier, have a look at this excellent webpage by Perry Babin:
http://www.bcae1.com/trnsfrmr.htm
After reading this tutorial, use the first calculator to determine your switching frequency and number of primary turns to get a reasonable (around 2000 gauss) flux density. Your frequency should be around 30-80KHz for most ferrites.
Then you should determine the physical arrangement (number of strands, gauge, etc) for best current distribution and minimize losses.
It is not an easy task and you will need to wind quite a lot of transformers until you get the desired result!
Nice to hear that you found my article at ESP useful.
In order to calculate the transformer turns, you first need to know what is the cross-sectional area of it and use the flux density formula to get the number of turns for a given frequency and flux density.
In order to make your life easier, have a look at this excellent webpage by Perry Babin:
http://www.bcae1.com/trnsfrmr.htm
After reading this tutorial, use the first calculator to determine your switching frequency and number of primary turns to get a reasonable (around 2000 gauss) flux density. Your frequency should be around 30-80KHz for most ferrites.
Then you should determine the physical arrangement (number of strands, gauge, etc) for best current distribution and minimize losses.
It is not an easy task and you will need to wind quite a lot of transformers until you get the desired result!
Off Topic Rant: Decimal Points
I wonder how commas and decimal points began to get interchanged. This problem may have severe consequences in some critical instances. Technically, this means 30 Hz accurate to 3 decimal places!
I am not blaming Adnancoskun. I think it began in Europe, and quite frankly, I am baffled by it. Someone from there should have known better.
I wonder how commas and decimal points began to get interchanged. This problem may have severe consequences in some critical instances. Technically, this means 30 Hz accurate to 3 decimal places!
I am not blaming Adnancoskun. I think it began in Europe, and quite frankly, I am baffled by it. Someone from there should have known better.
Re: Off Topic Rant: Decimal Points
I concur.
Wynand-
Just to further clear (or confuse) things, that's 30kHz switching frequency, which, for the SG3525 and all other double-ended PWM controllers, is one-half of the clock frequency, 60kHz, since two clock pulses are required for each full cycle.
Steve
Electrone said:
I concur.
Wynand-
Just to further clear (or confuse) things, that's 30kHz switching frequency, which, for the SG3525 and all other double-ended PWM controllers, is one-half of the clock frequency, 60kHz, since two clock pulses are required for each full cycle.
Steve
Re: Off Topic Rant: Decimal Points
In today's Wall Street Journal:
"The Scots invented the decimal point, then learned how to move it to the right."
Obviously an ad from a Scottish bank.
Electrone said:
In today's Wall Street Journal:
"The Scots invented the decimal point, then learned how to move it to the right."
Obviously an ad from a Scottish bank.
- Status
- Not open for further replies.