Comments on: Peculiar Case Of Secondary Wire Found Open In 2.1 Multimedia Speaker System Model Deltron

By: Parasuraman S

Parasuraman S — Sun, 17 May 2026 11:12:35 +0000

Many thanks for the correction, dear Albert!

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By: Albert van Bemmelen

Albert van Bemmelen — Sun, 17 May 2026 04:34:50 +0000

The link was the wrong one which I already reported to Jestine. It was supposed to be this MeanWell RS-15-5 power supply module, 15 W, 5 V, 3 A instead.

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By: Parasuraman S

Parasuraman S — Sun, 17 May 2026 02:28:37 +0000

In reply to Mark J.

Many thanks, dear Mark!

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By: Parasuraman S

Parasuraman S — Sun, 17 May 2026 02:26:08 +0000

In reply to Albert van Bemmelen.

Many thanks for your expert comments and suggestions! When I take up a work, I try to finish it with whatever I have. Unfortunately, I did not have a buck board that would deliver the 5V with the available other input from the Transformer. Many thanks once again, dear Albert, for your elaborate comments and guidance, which are very valuable to us all!

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By: Parasuraman S

Parasuraman S — Sun, 17 May 2026 02:22:49 +0000

In reply to Henrique Jorge G. Ulbrich.

Very true! SMPS cannot be used for working a Radio! Many thanks!

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By: Parasuraman S

Parasuraman S — Sun, 17 May 2026 02:22:04 +0000

In reply to Yogesh Panchal.

Yes, very true! I do agree with you! Sometimes, I used to replace the SMPS with a Transformer supply, wherever space was not a constraint! Many thanks, Yogesh Bai!

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By: Henrique Jorge G. Ulbrich

Henrique Jorge G. Ulbrich — Sat, 16 May 2026 19:20:09 +0000

In reply to Yogesh Panchal.

It is not only this, Yogesh. SMPSs are a kind of "noise difusers" polluting the RF spectrum (QRM for the ham radios). Extremely detrimental to communication.

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By: Mark J

Mark J — Sat, 16 May 2026 18:24:51 +0000

Clever fix Parasuraman. Thank you for sharing.

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By: Albert van Bemmelen

Albert van Bemmelen — Sat, 16 May 2026 10:56:17 +0000

Glad that you were able to fix this speaker system with partly defect transformer by adding a second 9V AC transformer to feed the 7805 regulator to be able to create the previously missing 5V DC. Instead of adding a new transformer another option would be to add a small 5V 3A module that can easily be fed by inputting 230VAC. These affordable ones:
They are not expensive, and light weight and about the same size as a small transformer so would make an easy fit.
I bought a couple of these to make safe replacement power supplies for the well known famous Commodore C64/128 computers. The power adapters I made with them require both a 9VAC transformer (9VAC/1A) and a 5V DC voltage (at least about 2,5A DC) but the modules are 3A max.
And good to know is that the 5V/3A modules that are sold on Aliexpress are a bit bigger why those on Amazon are to be prefered!

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By: Yogesh Panchal

Yogesh Panchal — Sat, 16 May 2026 10:20:38 +0000

Good Job!Sir
Still i found linear power supply supply are more reliable then SMPS.
SMPS Circuits having more protections still failure rate is high.

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