EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: JakeC on September 04, 2013, 06:38:19 pm
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Hi,
Could someone please explain what the difference between a switchmode and linear power supply is, I am very confused :-//
Thanks
Jake
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Really?
https://www.google.com/search?q=linear+power+supply+versus+switching+power+supply&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a (https://www.google.com/search?q=linear+power+supply+versus+switching+power+supply&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a)
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why is it not called a PWM power supply?
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Dave actually did a tutorial on this subject.
http://www.eevblog.com/2010/05/29/eevblog-90-linear-and-ldo-regulators-and-switch-mode-power-supply-tutorial/ (http://www.eevblog.com/2010/05/29/eevblog-90-linear-and-ldo-regulators-and-switch-mode-power-supply-tutorial/)
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why is it not called a PWM power supply?
With PWM you're actually getting variable-width pulses on the output. It's only good for powering some types of loads which wouldn't care much about that (some motors, heating elements, etc.) so you'll just get a more or less "averaged" result or where the easily-fooled human senses won't perceive the difference anyway (like the LED flickering at, say 400 Hz).
With SMPS, you're getting true DC voltage or at least, that's what you're aiming for. The design is much more complex, for example there's a feedback loop involved - something you won't see in a PWM circuit.
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Thanks for clearing that up quickly Zbig. ;) all the best.