ISOLATED SWITCHING POWER SUPPLY

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Hi guys, I´m new in projects with Switching Power Supplies. I was read the EPR32.pdf and I found a device to assembly.
This project contais a output with -24v/50mA
How I can swap the voltage to positive and impruve the Iout to 300mA for each output?

Thanks to all!!

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The EPR32 you cited is a DC-only design using DPA-Switch. The picture you attached is for an AC input application.Which is your preference? Also, is this a continuation of your previous thread, or a different design?

At any rate, what we'll need in order to proceed is an explicit spec including input voltage range and output voltage(s) and current(s). From this, we can select an appropriate PI device for your application, as well as the applicable design tool.

I looking for a AN to help me in assembly and I found the EPR32 . The outputs are more close to me needs(3v3, 5v, 24v each 300mA).

Me objective is around this needs. With 110/220 AC.

The circuit you cite in EPR32 is a forward supply with 48V input, and unsuitable for an AC input application. The circuit you actually need will look more like the picture you posted, which represents a flyback-based supply with AC input and multiple outputs. If you are comfortable with using a linear post regulator to generate 3.3V from the 5V output, the design can be trimmed down to two main outputs.

With 2 outputs: 5V @ 0.6A (300 ma additional for the 3.3V output) and 24V@0.3A, the total output power will be a little over 10W. A wide range of PI devices are available to service that power range, You will need to decide if you need any special features like extremely low no-load input power.

If you are looking for an evaluation board to start with, the closest I see in distributor stock is the DER-469. It has a wide range AC input and 2 outputs - 5 & 12V, with more than sufficient power for your needs. You would need to change the transformer and the 12V output components to get the 24V output you need, and the 3.3V output couuld be generated with a small low-drop linear regulator operating off the 5V output.

This power supply it's for studies with Automation(24v) and IOT(5v and 3v3).
I'm from Automation, I don't know how I can design a power source with these characteristics. Because this I start to use EPR32, the circuit is next to my needs.
If maybe excites a App to design I thanks for send me.

If you are not looking to design, lay out, and build your own SMPS board, the best option is to adapt an available evaluation board. The EPR-32 (ancient!) is not available, and would not in any case be adaptable to AC input.The closest available board to your requirements is the DER-469, with the addition of an outboard linear regulator (the TLV755 would work) to supply the 3.3V requirement from the +5V output. You can request a modified transformer via our rapid prototyping service to supply a 5V and 24V output. We can also advise on the remaining changes (component substitution) to turn the 12V output on the board into a 24V output. The DER-469 is currently available from Digi-Key.

Hi, PI-Wrench!
Looking for Power Supply in software development or any app and real time simulators. The software for PCB and layouts I'm using PROTEUS.
The problem is all math to development the corrections to adapt the EPR32 to my needs.
I like to build my owns PCBs, but a SWITCHING POWER SUPPLY I never done.

I hate to sound like a broken record, but the EPR32 is not adaptable to your needs, as it is based on a forward converter topology that will only work well with the DPA-Switch. The DPA-Switch has only a 200V drain voltage rating and will not handle the voltages needed for a universal AC input design. The PI devices that will handle this voltage range are best suited for a flyback-based design, which is simpler anyway, not requiring a coupled output choke for decent regulation.
The PI Expert software design tool gives you everything you need for a first-cut design, giving you a preliminary schematic and transformer design. As I mentioned before, the most sane approach for this requirement appears to be a basic 2-output (5V and 24V) supply with a small linear regulator for the 3.3V output fed from the 5V rail.. A low-droput regulator like the TLV755 appears to be a decent choice for regulating the 5V output down to 3.3V. As an extra, you get a free preload for the 5V output, which will help regulation. Suggested device types for your output power requirement are the InnoSwitch-EP (like used in the DER-469) and TinySwitch-4.
The PI-Expert design tool is downloadable, or you can use the on-line version available at the site.

Hi, PI-Wrench!!

The PI-Expert design tool it´s amazing! I literally design a switching power supply!

But the major problem: I´m from Brazil, and the numbers of available devices it´s very short. The most popular are TNY2xx family.

I found the DER110 and this is next to my needs (5v and 24v/300mA each). Maybe I will choose it. I would like to improve the Iout of 24v output to 500mA too. How I can do this?

We have several distributors in Brazil - contact information is on the PI main web site. The distributors should be carrying currently supported products.
If you buy older products on the grey market, you risk ending up with fakes or re-marked test escapes.
Currently supported products that would work for your application are TopSwitch HX and JX, TinySwitch 3 and 4, Innoswitch-EP.

As far as improving an older design for your needs, you're better off using PI Expert to design a new supply from scratch, especially if the design uses a product that is no longer supported.

Hi!
I used the Pi-Expert tool to design using a few components then I can buy in local store.
When I have the prototype I post the results.

Hi guys!
I use the tool Expert-Pi to develop that schematic. Also the L1, Chocke, it´s very hard to find to buy in local store. How I can remove, swap or modificate it?

Thanks to all!!

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Any well-stocked distributor should carry common mode EMI chokes.

Any distributor cust $35 shipping. It´s better to build a linear power supply...

Any distributor cust $35 shipping. It´s better to build a linear power supply...

No Brazilian distributors selling magnetic components?

This specific componnent yes! Just importing. The shipping is $35. Off taxes.
Because this I need a help to swap or improve.

You could try replacing the common mode choke with two separate inductors, but that means you still need inductors.

I thought about that. But I didn't know if it would work. I will buy two separate inductors.

Your major concern will be getting enough inductance in place for good EMI performance.