Tl494 smps

Silvio

Well-known member
but i think i need to get feedback from error amp.

when we don't use error amp the op-amp just turn on and off.
It means that error amp just turn on and off the tl494
But when we use feedback for error amp it change dutycycle every time to have stable output.

Is it true?

PWM works like this. If you have a small pulse width then the output has low current but voltage will still rise to the peak so for this reason you should have a minimum load attached to bring the voltage to the desired output. When the load is increased the voltage tend to drop so the error amplifier widens the pulse width hence it will deliver more current to the output until it brings the voltage again to the desired level. This happens at a very fast speed say at 3000 times per second.

Try to do some reserch on the net to learn more about the subject. Try wikipedia and write Pulse width voltage regulation
 
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noorworkshop

New member
can calculate the power of the EE ferrite core with diameters?
i had a 1000w inverter that it had two EE ferrite core but it use a pair of 85n60 for per core
i think that inverter just have 500w.
now i like to know cores power.
 

Silvio

Well-known member
Saying only EE is not enough you need to measure the cores and then we can estimate the their power
 

Silvio

Well-known member
The EE40 core mentioned will give you around 500 watts at 60Khz it would be less as the frequency goes lower and a bit higher at around 100KHz in half bridge topology.
 
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Silvio

Well-known member
Remove the feedback loop for the time being and see if you can draw current

Show us some scope shots across the input of the transformer so that we can see better what is happening
 
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