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Author Topic: Question about SMPS  (Read 1722 times)

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Offline zaokaTopic starter

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Question about SMPS
« on: September 25, 2013, 10:25:52 pm »
Why some SMPS are using upconverter circuit that makes around 400V and than its going to SMPS power supply?

I see that a lot in these new power supplies for TVs.

Why is that needed?
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Offline c4757p

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Re: Question about SMPS
« Reply #1 on: September 25, 2013, 10:32:34 pm »
Power factor correction. That circuit regulates the current waveform of the power supply so it doesn't draw power in the harsh spikes characteristic of a simple diode-capacitor rectifier.
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Offline Jay_Diddy_B

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Re: Question about SMPS
« Reply #2 on: September 25, 2013, 10:35:57 pm »
Hi,

The up converter is normally called a boost circuit in smps language.

The purpose of the boost stage is obtain a sinusoidal input current, power factor correction. Without the PFC the power factor will be about 0.65 for a capacitor input filter. with the PFC power factors of 0.95 or better are possible. In some areas PFC are mandatory for power consumptions over a certain limit.

I suggest a search for 'PFC'

Jay_Diddy_B
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