Simple Design Approach

Solcar

New member
When I first began tinkering with SMPS design several years ago, it occurred to me that it is a lot of trouble for the DIY circuit builder to have to examine and select from the numerous SMPS controller IC chips.

I might have selected the 555 timer chip as a basis for a general universal design, but found it had some of the drawbacks that dedicated controller chips have.

I decided to go more basic and use the simple charging and discharging of capacitors as just about the totality of the frequency generation or PWM. The simplest way to do that is with the Schmitt trigger CMOS gate.

Here is a sample voltage doubling PWM circuit. It is like the one I presently use on an e-motor assist bicycle. I used LTspice to greatly help with the design.
 

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Sierra

Valve Lover!
Nice to see the first post here about SMPS design.

In order for me to make SMPS, since I know nothing, I need to know the basics first.

What is SMPS basics?

Sierra
 

Solcar

New member
Hi Sierra,

One of the most basic principles of SMPS design is that the higher frequency than 60hz waveform driving the transformer allows much less iron to be needed in it.

Another basic principle is a negative one, however. It is that the higher frequencies involved in SMPS tend to cause electrical interference.
 

destroyer x

Compulsive builder
Lovely schematic posted...good idea...very kind...very usefull.... but i think i would need more detailed explanation.... and i am not stupid...have studied electronics by 50 years...studied in Sony Japan, Motorola and Telefunken...also i am an amplifier designer myself.

The explanation is only scratching the surface...not good enougth and not detailed enough.

Example considering the supplies goes plugged into the mains:

- "The AC voltage enters D1 and is rectified and filtered by C1...in series with these two part we have a capacitor and a bypass switch.... when the capacitor is shorted you will be using 110 volts in the input... when the capacitor is in the circuit, not shorted, not bypassed, then you may enter with 220 Volts AC....."

This is detailed..and step by step... i would like to ask you, PLEASE, to do this way to help the ones are ignorant (does not know things) about switching power supplies.

The way you said is something we see in the internet as supply presentation, only surface, not going deep..not effective to teach anybody.

I am sorry if your intention (i cannot know what goes in your mind) is not to teach....if the intention is "not to teach"..then it is OK!

regards and thanks by the effort, kindness, interest and attention.

Carlos
 

Justicer

New member
Don't you see this man wants to fool you dx!

He do not want to teach nobody, he is just pretending he is teaching

Hermano brasileno babaca
 

destroyer x

Compulsive builder
So, you are a frustrate man?.... banished!...kicked out from the diyaudio...kicked alike an animal... and now wants to bother?
Could you not learn something from that?... you were banished because you are no good.

But will not complain to moderators, you, at least, have courage!.. and this i respect.

Carlos
 

Solcar

New member
Carlos, what I was able to do for you now is add some labels to the diagram. I will be glad to try to answer more questions. If you like more explanation about portions of the circuit, I will be glad to try to clarify.
 

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destroyer x

Compulsive builder
I want, i need, i hope someone can help me and help my Brazilian friends that came here to learn SMPS, i hope someone skilled, will help us to understand how the circuit works in details.... a circuit description... very detailed..in order to me and my people understand enougth to create, modify and adjust output voltage in any SMPS supply...we want the understanding, not the circuit names..we want to know the flow of current, each stage function, the currents, frequencies and voltages in each point... that's what we want and we are searching the one can do that for us.
 

destroyer x

Compulsive builder
I want not only a bureaucratic description of a SMPS... starting to explain that this means Switching Mode Power Supply... we want the real thing...the understanding of how it works in details..something only a guy that really understands deeply can explain us... i hope you are the one to be the SMPS expert here.....i can do that for audio amplifiers..i can go microscopic and explain you how is the electron belt colour.

The description, i hope, would be alike a teacher explaining how the circuit works...alike a circuit description you read in professional equipments..stage by stage, circuit by circuit, step by step, showing currents, voltages, frequencies and waveforms.
 

destroyer x

Compulsive builder
The description i am searching is alike the ones i will try to make (I know almost nothing about these supplies...i am totally ignorant about them).

Image a supply, a SMPS that can receive 110 or 220 volts, manually switched in the input... a key you control up and down..to 220 or 110 volts... this supply (imaginary, for instance, as an example) can put out 75 plus 75 volts DC and 5 plus 5 amperes.... then the guy post the schematic, the entire one...and in the second post he starts to explain...he post a sketch (scratch) of the input and then start to describe the operation this way:
 

destroyer x

Compulsive builder
110 or 220 volts is selected in the switch SW1.... when the switch is selecting 110 volts, capacitor C1 is bypassed...so, its capacitive reactance does not interfere with the circuit and 110 volts AC goes directly, without attenuation to the fuse F1, then goes to the diode D1 that rectifies and C2 is there to filter... in this moment we gonna have 154 volts DC measures in the C2 leads.

When the switch is positioned in 220 volts, then the capacitor C1 is not bypassed..it's reactive capacitance behaves alike a resistance to the mains frequency (50 or 60 hertz) and reduces the 220V alternated to almost 110 volts... this is the way the input voltage is selected.
 

destroyer x

Compulsive builder
Got it my dear?....i would like to have something alike that... a real, clear, precise and trully explanation, from someone that really understand and do not copy text book words....and i hope, this one is you, that will remove our feet, deeply submerged in the dirty mud of ignorance.

regards,

Carlos
 

Solcar

New member
Carlos, my friend, I think what you seek is the basics first. I wouldn't even worry about the 120/220 volt selector switch since in DIY power supplies it is rarely included. I've never used one.

Take my simple circuit and build it in your electronics simulator. It will allow you to perfectly see how each of the building blocks works. A picture is worth 1000 words!

If you use LTspice, I can give you access to all of my circuits. I am totally non-profit and freely share everything. You could then see how simple SMPS is in its basics. long explanations aren't the best way to learn.
 

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Justicer

New member
You can see Dx, you see the one is trying to fool you, pretending you want the basic, snobbing usted hermano, saying this is basic, one more pretending, want to be expert and know nothing, unable to explain even the basic and saying not needed, saying to you, learn by yourself.

Usted, parrero hermano stupido, know nothing about, this guy also knows nothing about, a big mierda es esto forum, que tomen en el culo essos hijos de una -----a
 

destroyer x

Compulsive builder
Yes Justicer, i do not like you, but i see you have courage and what you talk make sense to me...make more sense then the words said by solcar..... i do think he is trying to remove himself too... said.... put in the simulator and learn by yourself.

Thank you anyway solcar..by the nothing you done to me, to my friends and to the forum.

regards,

Carlos
 

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Tess Stickle

New member
The description i am searching is alike the ones i will try to make (I know almost nothing about these supplies...i am totally ignorant

buy a few text books and then read them try power supply cookbook by marty brown for a start do you want to be spoon fed everything
designing a smps psu is more difficult than some stupid amplifier
 

Sierra

Valve Lover!
buy a few text books and then read them try power supply cookbook by marty brown for a start do you want to be spoon fed everything
designing a smps psu is more difficult than some stupid amplifier

Are you able to help into SMPS? make a good WORKING design for us to learn?
 

destroyer x

Compulsive builder
I want all explanation Solcar.... the circuit description in details..not to be posting questions as they will be hundreds..and questions depends to have know how to make these questions.... an indian. in Guinea, cannot ask about hidraulical system of an airplane that fell down in the jungle..i am that indian...only the guy that REALLY knows, can talk about that subject.

Do you really know to explain or your do not know to explain....will you say do not want?

It looks you do not want...when we ask people to post question is because we do not feel courage to face the challenge to teach others..am i rigth or wrong?

regards,

Carlos
 
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