Stepping Down Voltage Most Effeciently

Thread Starter

JustusS

Joined Jul 23, 2019
13
Transformer
X-rated Capacitor
Resistor
Phase angle control
(Any others not listed)

Is a precision rectifier more effecient than a syncronous rectifier? Ie, what actually is the power dissipation of an ideal diode?? And is it designed to dissipate less power than an SR typically?

In the case of an X-rated capacitor, is power dissipation equivalent to the [V^2 ÷ ESR], or [V^2 ÷ Capacitive resistance]?

Why can't you PWM a full bridge with a power MOSFET? Is phase angle control more effecient? Zero point switching only has to turn components on twice per period, while PWM-ing a full bridge output would require a higher freq of switching compared to diac+triac, which in turn draws more power?


How about a combination of different types of V regulation? ...

(Phase angle control) + (SCR) ?
(Transformer) + (phase angle control) ?


Interested in finding an effecient way to variably regulate voltage. Power dissipation generally goes up with lower load requirements and looking to learn and understand the ~% of power dissipated in various techniques of rectification and voltage regulation. I don't have a cct or schematic I'm currently working on, just looking to acquire knowledge to further my understanding. Thanks.
 
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crutschow

Joined Mar 14, 2008
26,413
I have no idea what an X-rated capacitor is.
Is it one that can only be used by someone over 18? :rolleyes:
Is a precision rectifier more effecient than a syncronous rectifier?
They are the same thing.
what actually is the power dissipation of an ideal diode?
It's generally the square of the current times the on-resistance of the MOSFET used as the ideal diode.

As far as the rest of your questions, most high efficiency DC supplies convert the incoming AC to DC with a rectifier-capacitor circuit, and then convert that to the desired DC voltage with a switching regulator.
Other schemes are generally less efficient.
 

Thread Starter

JustusS

Joined Jul 23, 2019
13
I have no idea what an X-rated capacitor is.
Is it one that can only be used by someone over 18? :rolleyes:
They are the same thing.
It's generally the square of the current times the on-resistance of the MOSFET used as the ideal diode.

As far as the rest of your questions, most high efficiency DC supplies convert the incoming AC to DC with a rectifier-capacitor circuit, and then convert that to the desired DC voltage with a switching regulator.
Other schemes are generally less efficient.

Lol and thanks for the reply. Do you know who makes a high effeciency regulator?

REGULATORS, MOUNT UP!
LOL HAD TO..

Looking to achieve 93%+ total effeciency. Was looking at the LM2596, but would like an even better option if it exists? Was thinking if AC input to full bridge were phase angle controlled that I could dissipate less power on DC side step down, or regulation. Then further increase effeciency by swapping full bridge with SCR?

Bill Nye should have done a remix of this one back in the day lol..
 
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