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Joyo PowerSupply 2 schematic  [schematic]

PostPosted: 09 Nov 2017, 19:55
by apollomusicservice
From the Joyo's review it's isolated.

Re: Joyo PowerSupply 2 schematic

PostPosted: 09 Nov 2017, 20:01
by plush
apollomusicservice wrote:From the Joyo's review it's isolated.


Turns out it is not.
Nothing surprising.

Re: Joyo PowerSupply 2 schematic

PostPosted: 10 Nov 2017, 02:53
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.

Re: Joyo PowerSupply 2 schematic

PostPosted: 10 Nov 2017, 03:03
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

Re: Joyo PowerSupply 2 schematic

PostPosted: 10 Nov 2017, 07:40
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.

Re: Joyo PowerSupply 2 schematic

PostPosted: 11 Nov 2017, 20:51
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.

Re: Joyo PowerSupply 2 schematic

PostPosted: 11 Nov 2017, 21:27
by 287m
Yes, please.

Re: Joyo PowerSupply 2 schematic

PostPosted: 11 Nov 2017, 23:20
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.

Re: Joyo PowerSupply 2 schematic

PostPosted: 12 Nov 2017, 15:12
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

Re: Joyo PowerSupply 2 schematic

PostPosted: 12 Nov 2017, 16:30
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.

Re: Joyo PowerSupply 2 schematic

PostPosted: 12 Nov 2017, 16:51
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.

Re: Joyo PowerSupply 2 schematic

PostPosted: 13 Nov 2017, 15:09
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.

Now back to the DIY talk...

Re: Joyo PowerSupply 2 schematic

PostPosted: 13 Nov 2017, 18:45
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

Re: Joyo PowerSupply 2 schematic

PostPosted: 13 Nov 2017, 18:59
by Ice-9
sorry picture did not post correctly above, so I will try again.

Image

Re: Joyo PowerSupply 2 schematic

PostPosted: 14 Nov 2017, 05:31
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!

Re: Joyo PowerSupply 2 schematic

PostPosted: 22 Nov 2017, 14:57
by krome_magnon
So, what technology would the Gig Rig Isolator be using?

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

Obviously not a multiple secondary transformer.

Re: Joyo PowerSupply 2 schematic

PostPosted: 24 Nov 2017, 11:35
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.

Re: Joyo PowerSupply 2 schematic

PostPosted: 24 Nov 2017, 13:18
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.

Re: Joyo PowerSupply 2 schematic

PostPosted: 24 Nov 2017, 17:06
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.

Re: Joyo PowerSupply 2 schematic

PostPosted: 24 Nov 2017, 17:18
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