Need reference design of a 5V 80W to 100W DC SMPS

[MAXPAYNE]

Can anybody give me a reference design of a flyback 5V 18A or more DC supply with 115V AC input ?

I searched the chip manufacturer side but only got of 12V.

 

[BradtheRad]

For unknown reasons I frequently make a pastime of running simulations.

Here is a basic concept of the flyback. Component values have been adjusted to do what you want. Control circuitry is not shown.



The power supply is 120 VDC. This could come from rectifying 115 VAC, and filtering it.

Notice the large pulses of current flowing in the secondary stage. It could be more efficient to use a full H-bridge to a step-down transformer.

 

[MAXPAYNE]

For unknown reasons I frequently make a pastime of running simulations.

Here is a basic concept of the flyback. Component values have been adjusted to do what you want. Control circuitry is not shown.



The power supply is 120 VDC. This could come from rectifying 115 VAC, and filtering it.

Notice the large pulses of current flowing in the secondary stage. It could be more efficient to use a full H-bridge to a step-down transformer.

Thanks BradtheRad. Which software did you use for simulation ?

Can you give me a reference design of Full H bridge 5V 80W or more design ?

 

[Anna Conda]

Why not hire a consultant power electronics engineer?

 

[MAXPAYNE]

Why not hire a consultant power electronics engineer?

I am not professional. I am just a student and setting up my personal lab. Thats why I am looking for ready solutions so that I can finish setting up my lab quickly.

 

[Anna Conda]

OK, there must be plenty of old PC power supplies giving more than 20A at 5V, possibly suitable?

 

[MAXPAYNE]

OK, there must be plenty of old PC power supplies giving more than 20A at 5V, possibly suitable?

Nope. due to there size.

 

[BradtheRad]

Thanks BradtheRad. Which software did you use for simulation ?

This is Falstad's animated interactive simulator. Free to download and use at:

www.falstad.com/circuit

Can you give me a reference design of Full H bridge 5V 80W or more design ?

Here is the bare-bones concept of an H-bridge. The control circuitry is not shown.

The 120 VDC supply is turned into square waves, then fed to the transformer primary. The secondary is 6 VAC square waves. You rectify and filter it to get smooth 5 VDC.

20 kHz is a typical operating frequency. My simulated transformer has specs which are compatible (more or less).

As you know the transformer can be much smaller than an everyday 50/60 Hz power transformer.

 

[schmitt trigger]

I am not professional. I am just a student and setting up my personal lab. Thats why I am looking for ready solutions so that I can finish setting up my lab quickly.

Under this conditions, and because designing and building a off-line non-insuilated power supply is NOT a trivial matter, I would do the following:

-Take a 240/120 volt to 24 volt @ 4 amp transformer. Rectify and filter the output. That takes care of the isolation.
-You now will have raw DC in the range of 32 to 40 volts. Now search manufacturer websites for reference designs to step the voltage down to a regulated 5 volts. Most likely you'll find buck designs. There will be plenty of them.