Joyo - JP-02 PowerSupply 2  [schematic]

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apollomusicservice
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Post by apollomusicservice »

From the Joyo's review it's isolated.
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Post by plush »

apollomusicservice wrote:From the Joyo's review it's isolated.
Turns out it is not.
Nothing surprising.

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Post by Ice-9 »

plush wrote:
apollomusicservice wrote:From the Joyo's review it's isolated.
Turns out it is not.
Nothing surprising.
well that's no surprise is it. they use the wording 'isolated outputs' to mean separate output connectors and not actual isolated outputs. It is a bad play on wording.
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Post by Ice-9 »

to be fair only sellers describe it as isolated outputs and the joyo website describe it as short circuit isolated on individual outputs. two complete different meanings
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

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Post by apollomusicservice »

Ice-9 wrote:to be fair only sellers describe it as isolated outputs and the joyo website describe it as short circuit isolated on individual outputs. two complete different meanings
On the Joyo's original box the first sentence is: Ten isolated output.
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Post by Ice-9 »

apollomusicservice wrote:
Ice-9 wrote:to be fair only sellers describe it as isolated outputs and the joyo website describe it as short circuit isolated on individual outputs. two complete different meanings
On the Joyo's original box the first sentence is: Ten isolated output.
so even joyo describe it differently on the box and in other blurb. Does anyone fancy a forum project with real isolated outputs ? I might do one if anyone is interested.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

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Post by 287m »

Yes, please.

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Post by krome_magnon »

Ice-9 wrote:Does anyone fancy a forum project with real isolated outputs ? I might do one if anyone is interested.
Oh yes!

I can't imagine how it's done without individual taps off a transformer into normal linear regulator ICs. Would love to know how to do it.
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Post by Frabbio »

Is it possible to have several isolated outputs starting from a single power supply using PWM ICs like the SG3525, give a look here.
http://www.aresaudio.com/stomps-power-supply.html

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Post by apollomusicservice »

Frabbio wrote:Is it possible to have several isolated outputs starting from a single power supply using PWM ICs like the SG3525, give a look here.
http://www.aresaudio.com/stomps-power-supply.html
Supply with switching technology and half-wave rectification, I don't think that it's good solution for audio equipment.

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Post by Frabbio »

It should work around 30khz switching frequency , bu eventually one can modify it to run on higher frequencies, i don't think it will cause any audio interferences.
Of course a classic linear power supply is better for audio, but it will need a secondary for each output.

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Post by howmuch »

FYI
A very good value-for-money isolated power supply is the Harley Benton PowerPlant Junior (not the bigger one).
Outwardly, it looks similar to the T-Rex Fuel Tank Junior.
The gutshots here show that it has 5 secondary transformer taps, each with their own bridge rectifier and regulator.

It's odd that while most Harley Benton pedals are rebadged Joyos, Joyo don't make this power supply.

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Post by Ice-9 »

I have had a quick look at what I think would be the most cost effective way to design an isolated PSU, it is using the small 'Block' transformers that have 2 completely separate secondaries per transformer which will allow for 2 outputs per Tx. I haven't bought any transformers yet to try out and the ones shown in the 3d render are just examples. I will need to select suitable TX's and then look at the correct dimensions for the PCB.

The PCB I have layed out as an example has 4 isolated 9v DC outputs with 100mA regulators and 2 9v DC outputs using TO220 1amp regulators . The PCB so far can be expanded easily just buy duplicating each section of two outputs.

As I say though, so far this is just an example of type and layout.

Image
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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Post by Ice-9 »

sorry picture did not post correctly above, so I will try again.

Image
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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Post by camljenkins94 »

Oh, it is isolated, let me show you! *proceeds to blow all of the fuses in it* See, every output is now completely isolated!

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Post by krome_magnon »

So, what technology would the Gig Rig Isolator be using?

https://shop.thegigrig.com/isolator/

Obviously not a multiple secondary transformer.
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Post by marshmellow »

There are isolated DC-DC topologies that use transformers which are much smaller compared to the transformer in a standard AC supply. Could be that, or they are just as generous with the term isolated as Joyo.

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Post by alblupo »

Ice-9 wrote:sorry picture did not post correctly above, so I will try again.

[ Image ]
I agree. A friend of mine design a modular power supply following that approach. You can have a power bus, and than attach modules that has a transformer and one or two outputs. Accordint to the wiring and the transformer you can get the different voltages and currents you need.

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Post by plush »

marshmellow wrote:There are isolated DC-DC topologies that use transformers which are much smaller compared to the transformer in a standard AC supply. Could be that, or they are just as generous with the term isolated as Joyo.
You can't isolate DC from DC via transformer. Transformers work only with ac. Since this isolator runs on DC, it's based on pure bullshit.

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Post by lietuvis »

plush wrote:
marshmellow wrote:There are isolated DC-DC topologies that use transformers which are much smaller compared to the transformer in a standard AC supply. Could be that, or they are just as generous with the term isolated as Joyo.
You can't isolate DC from DC via transformer. Transformers work only with ac. Since this isolator runs on DC, it's based on pure bullshit.
https://power.murata.com/en/nmk1209sc.html

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