# Can this schematic actually produce 12V 60A output?

#### schmitt trigger

Joined Jul 12, 2010
496
That is the problem with circuits found on the web. They have most likely not being reviewed by anyone else.

#### Audioguru again

Joined Oct 21, 2019
4,536
Many people over there who cannot speeky zee Engrish post videos about anything so that You Tube pays them each time somebody views a You Tube ad.

#### Deleted member 440916

Joined Dec 31, 1969
0
Trafo design is rubbish, skin depth at 50Khz is ~0.3mm, this joke schematic uses 1.3 & 1.7mm wire lols
Simple answer to OP is NO chance!!

#### laco22

Joined Oct 31, 2017
19

I will make it and post the results.

#### ronsimpson

Joined Oct 7, 2019
2,005
I am making the SPMS in the YouTube video above.
Forward, flyback, resonant, qusi-resonant, LLC, ....?
How does it work? (not just duty cycle changes)

#### Ian0

Joined Aug 7, 2020
4,861
Those MOSFETs are going to be really upset by that amount of capacitive load. Unless it's LLC resonant, then it needs an output inductor.
At that voltage, the output diode should be a schottky.

#### DickCappels

Joined Aug 21, 2008
8,686
I just love the audio. Reverb on the voice and constant background music. Where did this guy learn TV production?

#### laco22

Joined Oct 31, 2017
19
Thank you all for your replies.
Perhaps I don't have a lot of knowledge in this field.
I will try while learning a little more.

#### ronsimpson

Joined Oct 7, 2019
2,005
I think there is a inductor missing in the output stage.

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#### laco22

Joined Oct 31, 2017
19
I think there is a inductor missing in the output stage.
View attachment 225954

Thanks for providing a detailed image description.

I am now studying the principle and theory of half bridge DC-DC converter.
It seems that my knowledge is lacking a lot.
Thanks for the help.

#### DickCappels

Joined Aug 21, 2008
8,686
If this is your first switching power supply project, I think you will do much better to start out with a lower voltage and lower power design like one in an application note or semiconductor datasheet. The schematic show signs of not being designed as much as being discovered.

Your first switching supply should not cost much and not be dangerous to work on this seems to be both expensive and dangerous. As @fourtytwo pointed out the transformer is entirely wrong for this application. Sadly, I would be very surprised it it works at all as drawn.

#### LowQCab

Joined Nov 6, 2012
1,922
SMPS's are NOT a beginner project.
Especially extremely High Current versions.

Start looking for a "MOT" (Microwave Oven Transformer).
Any used Microwave Oven will work.
Check-out the hundreds of Videos on YouTube on how to Modify any "MOT".

You will need to remove the Secondary Windings, and the "Magnetic Shunts" from the Core,
then it is simply a matter of obtaining some #6-gauge, Fine Stranded, High Temperature Insulated, Wire.
You will probably need less than 16 Turns of Wire on the Core to get 12 Volts AC,
just keep adding Turns until you get the Voltage you want.
Smaller Gauge Wire will melt and cause a FIRE at ~60 Amps, DON'T SCRIMP ON THE WIRE.

One single Electrolytic Capacitor is not going to survive ~60 Amps,
you will need more like 10 to 15 smaller Caps that are RATED FOR THAT MUCH RIPPLE CURRENT,
like 15 of these .......... EGPD350ELL752MM40H ...... from DigiKey Electronics.
15 X $3.96 =$59.40, 35V, 7500mfd, which can handle 6-Amps of "Ripple-Current" @120hz.
So that's, 15 X 7500mfd = 112,500mfd, at, 15 X 6A = 90Amps Ripple Current.

Then you need a Bridge Rectifier ........ Well it seems that they don't make them that big,
so you'll have to cobble-up your own out of 4- individual Diodes,
like these ........ VS-150EBU02 ...... Also from DigiKey,
4 X $7.05 =$28.oo, 200-Volts, 150-Amps,
These Diodes will require careful attention to how the Physical Connections are made to them,
and how they are mounted to the Heat-Sink,
60-Amps is NOT a trivial matter, minimum #6-Gauge Wire.
These Diodes will also have to be mounted on a proper Large Heat-Sink because
they will Dissipate..... 0.8V X 60A = 48-Watts EACH (192 Watts Total), under a 60-Amp Load,
and so the Heat Sink will have to have a Cooling Fan to keep temps under control.

12-V X 60-A = 720 Watts,
this is probably the maximum rated Wattage for your average Microwave-Oven-Transformer,
and they are not rated for continuous duty, so the Transformer may need a Cooling Fan as well.

This is basically a well filtered DC- Arc-Welder.
It will start most small Cars without the help of a Battery.
Very few Batteries can withstand being Charged with 60-Amps for more than a few minutes.

Are you still sure that you need 60-Amps ????
.
.

Last edited:

#### jpanhalt

Joined Jan 18, 2008
11,088
12-V X 60-A = 720 Watts,
this is probably the maximum rated Wattage for your average Microwave-Oven-Transformer,
and they are not rated for continuous duty, so the Transformer may need a Cooling Fan as well.

This is basically a well filtered DC- Arc-Welder.
It will start most small Cars without the help of a Battery.
Very few Batteries can withstand being Charged with 60-Amps for more than a few minutes.
Ha, ha. Where do you live? Microwaves are in the 1200W range, as is my Sears Kenmore that is a 27-year old one.

As for a 720W arc welders, even the cheapest at Harbor Freight is 2400W supply (20A @ 120V).

#### laco22

Joined Oct 31, 2017
19
SMPS's are NOT a beginner project.
Especially extremely High Current versions.

Start looking for a "MOT" (Microwave Oven Transformer).
Any used Microwave Oven will work.
Check-out the hundreds of Videos on YouTube on how to Modify any "MOT".

You will need to remove the Secondary Windings, and the "Magnetic Shunts" from the Core,
then it is simply a matter of obtaining some #6-gauge, Fine Stranded, High Temperature Insulated, Wire.
You will probably need less than 16 Turns of Wire on the Core to get 12 Volts AC,
just keep adding Turns until you get the Voltage you want.
Smaller Gauge Wire will melt and cause a FIRE at ~60 Amps, DON'T SCRIMP ON THE WIRE.

One single Electrolytic Capacitor is not going to survive ~60 Amps,
you will need more like 10 to 15 smaller Caps that are RATED FOR THAT MUCH RIPPLE CURRENT,
like 15 of these .......... EGPD350ELL752MM40H ...... from DigiKey Electronics.
15 X $3.96 =$59.40, 35V, 7500mfd, which can handle 6-Amps of "Ripple-Current" @120hz.
So that's, 15 X 7500mfd = 112,500mfd, at, 15 X 6A = 90Amps Ripple Current.

Then you need a Bridge Rectifier ........ Well it seems that they don't make them that big,
so you'll have to cobble-up your own out of 4- individual Diodes,
like these ........ VS-150EBU02 ...... Also from DigiKey,
4 X $7.05 =$28.oo, 200-Volts, 150-Amps,
These Diodes will require careful attention to how the Physical Connections are made to them,
and how they are mounted to the Heat-Sink,
60-Amps is NOT a trivial matter, minimum #6-Gauge Wire.
These Diodes will also have to be mounted on a proper Large Heat-Sink because
they will Dissipate..... 0.8V X 60A = 48-Watts EACH (192 Watts Total), under a 60-Amp Load,
and so the Heat Sink will have to have a Cooling Fan to keep temps under control.

12-V X 60-A = 720 Watts,
this is probably the maximum rated Wattage for your average Microwave-Oven-Transformer,
and they are not rated for continuous duty, so the Transformer may need a Cooling Fan as well.

This is basically a well filtered DC- Arc-Welder.
It will start most small Cars without the help of a Battery.
Very few Batteries can withstand being Charged with 60-Amps for more than a few minutes.

Are you still sure that you need 60-Amps ????
.
.

There seems to be a part that I thought very easily.
I can't understand all of your words right now, but I will study according to what you said.
And, I need 60A is right.

#### LowQCab

Joined Nov 6, 2012
1,922
Maybe you can use 2- Large Computer Power Supplies ?

( If you need more than "exactly" 12-Volts,
the Computer Power Supplies will have to be Modified to increase Voltage Output ).

Automotive Battery Chargers require 14 to 17 Volts to work.
.
.

#### laco22

Joined Oct 31, 2017
19
Maybe you can use 2- Large Computer Power Supplies ?

( If you need more than "exactly" 12-Volts,
the Computer Power Supplies will have to be Modified to increase Voltage Output ).

Automotive Battery Chargers require 14 to 17 Volts to work.
.
.
The load can be divided into 30A and 30A respectively.
The load is a large-capacity LED panel.
The first and second floors are divided, so they can be divided.

The led panels only need 12V.

Thanks.