Author Topic: High efficiency linear regulators  (Read 436 times)

Offline Shonver

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High efficiency linear regulators
« on: June 22, 2016, 04:25:46 PM »
Guys, ever built a regulated power supply using 78-series regulators - you know: 7805 for 5V, 7812 for 12V - and then found that the regulator needed a massive heat sink due to the power dissipation (larger than can fit into the allotted space)? There is a direct replacement in switch mode that of course runs cooler. Check it out:

Quote
The R-78xx-Series high efficiency switching regulators are ideally suited to replace 78xx linear regulators and are
pin compatible. The efficiency of up to 97% means that very little energy is wasted as heat so there is no need for
any heat sinks with their additional space and mounting costs. Low ripple and noise figures and short circuit , overload
and over-temperature protection round off the specifications of this versatile converter series. This R-78xx-
0.5 is fully certified to EN 55022 (Emissions), and EN55024 (Immunity) EMC Standards and for EN-60950-1 Safety.

http://www.recom-power.com/pdf/Innoline/R-78xx-0.5.pdf
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Offline tangmonster

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Re: High efficiency linear regulators
« Reply #1 on: June 30, 2016, 08:58:39 AM »
Guys, ever built a regulated power supply using 78-series regulators - you know: 7805 for 5V, 7812 for 12V - and then found that the regulator needed a massive heat sink due to the power dissipation (larger than can fit into the allotted space)? There is a direct replacement in switch mode that of course runs cooler. Check it out:

http://www.recom-power.com/pdf/Innoline/R-78xx-0.5.pdf

If your application can handle a ripple voltage of around 20mV around 300Khz then these would work great.

They are just fine for "normal" audio use but the purist might stay away from them due to the high frequency noise.



Offline handsome

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Re: High efficiency linear regulators
« Reply #2 on: June 30, 2016, 09:35:37 AM »
If the regs are getting that hot then they probably have too many volts across them (78xx and 79xx can only pass a max 1 amp) they only need a minimum of ~3V across them. Rather put an RC filter before them it will drop the voltage they see on their input plus add some extra filtering. Switching regs may have high frequency frequency noise issues as Tang pointed out - audiophiles on the other hand, will definitely have issues