Are Linear Bench Supplies Really Quieter Than Switchers?

This is where we talk about testing, measuring and repairing things. Sometimes we have to repair the equipment we use to test, measure and repair other things. It's an endless cycle of fixing the broken things we need to fix other broken things.
billshurv
Posts: 362
Joined: Thu Feb 01, 2018 7:07 am

Re: Are Linear Bench Supplies Really Quieter Than Switchers?

Post by billshurv » Wed Nov 28, 2018 11:15 am

Let me pull mine out and have a look how its tracked. Failing that will ask Jan.

That's a point. 12V to 10V reg will only have to drop 4.5V worst case with a lead acid battery. Hardly really needs to regulate much as long as it drops a couple of volts. (13V protection zener on board 9-10V recommended as max input)

Jacko
Posts: 8
Joined: Sat Dec 16, 2017 1:02 pm

Re: Are Linear Bench Supplies Really Quieter Than Switchers?

Post by Jacko » Tue Feb 26, 2019 12:03 pm

mediatechnology wrote:
Wed Nov 28, 2018 10:53 am
Thanks for the update. I bet the AC-powered performance WRT leakage current and hum will vary greatly with the particular USB supply used.

Still curious to see if there's a direct galvanic path between the USB DC 0V and the Switcher output 0V.
The power supply uses the LT3471 regulator and there does not seem to be galvanic isolation (though I am certainly not an expert in power supplies!).

There is a video at https://youtu.be/0Sb2mIbpzFk which has a good close look at the pcb. There seems to be a clear connection between the input and output grounds through the top copper plane.

Closeup photo: https://linearaudio.nl/sites/linearaudi ... ropped.jpg

best regards, jacko

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