# SMPS, I need a diagram over an smps

#### eltock

Joined Oct 29, 2020
9
Hi. i need a diagram over an smps, the input set to 9V from an 9V battery to +5V/500mA and -5V/200mA on the output, and i use an mc34063a?

#### Lyes

Joined Nov 25, 2019
12
HI ELTOCK
you need a step down and a voltage inverting converters
the two diagrams are in the datasheet of MC34063A

#### eltock

Joined Oct 29, 2020
9
HI ELTOCK
you need a step down and a voltage inverting converters
the two diagrams are in the datasheet of MC34063A
Do you have a link to the datasheets because i cant see it in those i have. dont you think i can make it as a buck converter

#### eltock

Joined Oct 29, 2020
9
Do you have a link to the datasheets because i cant see it in those i have. dont you think i can make it as a buck converter
I am all new in electronics, sorry.

#### ericgibbs

Joined Jan 29, 2010
12,270
hi el.
This is the datasheet.
E

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#### eltock

Joined Oct 29, 2020
9
Someone who has a diagram i can look at

#### Lyes

Joined Nov 25, 2019
12

#### eltock

Joined Oct 29, 2020
9
i all new in el
i am all new in electronic. the thing i cant figure out is det circuit that comes after the mc34063a where the output to +5v and -5v is

#### eltock

Joined Oct 29, 2020
9
i have heard someone said i should need some kind of mosfet

#### Lyes

Joined Nov 25, 2019
12
you don't need a mosfet because your output current don't exceed 1.5A
i have done a quick calculation for the step down (no optimization of the losses) i got that
Ct=520pF (50kHz ton=13µs toff=7µs)
L=41.6µH for 9Vmin
Rcs=0.28Ohm
Co=115µF
R1=12K R2=36K

#### Papabravo

Joined Feb 24, 2006
15,521
If you are that new to electronics, this is a really really bad first project for several reasons:
1. You should not build this design as a one-off breadboard.
2. It should be fabricated on a PCB (Printed Circuit Board).
3. The knowledge required to select the proper components exceeds your current knowledge level by several orders of magnitude.
4. The diagram above is for the buck converter ONLY!
5. You need a separate design for the negative supply.
If you are trying to construct a power supply for experiments, I suggest you start with two 9V batteries and a pair of linear regulators producing ±5 VDC supplies. This circuit will work just fine on a breadboard. Get your feet wet before trying to swim the English Channel. You need to learn to crawl and walk before trying to run a marathon.

You really really need to learn how to find and download datasheets.
For the positive regulator you google: "LM317 datasheet"

For the negative regulator you google: "LM337 datasheet"
and this is the top hit

Get the idea?

#### eltock

Joined Oct 29, 2020
9
If you are that new to electronics, this is a really really bad first project for several reasons:
1. You should not build this design as a one-off breadboard.
2. It should be fabricated on a PCB (Printed Circuit Board).
3. The knowledge required to select the proper components exceeds your current knowledge level by several orders of magnitude.
4. The diagram above is for the buck converter ONLY!
5. You need a separate design for the negative supply.
If you are trying to construct a power supply for experiments, I suggest you start with two 9V batteries and a pair of linear regulators producing ±5 VDC supplies. This circuit will work just fine on a breadboard. Get your feet wet before trying to swim the English Channel. You need to learn to crawl and walk before trying to run a marathon.

You really really need to learn how to find and download datasheets.
For the positive regulator you google: "LM317 datasheet"

For the negative regulator you google: "LM337 datasheet"
and this is the top hit

Get the idea?
Thats why i am asking, because i am New, and Thats why i need specific diagram over the output

#### eltock

Joined Oct 29, 2020
9
Thats why i am asking, because i am New, and Thats why i need specific diagram over the output
I get it all. But it is important that it is a mc34063a says My teacher, All I need is det +/- output diagra.

#### Papabravo

Joined Feb 24, 2006
15,521
I get it all. But it is important that it is a mc34063a says My teacher, All I need is det +/- output diagra.
You didn't say there was a teacher involved, and you didn't post in Homework Help. His motivation for introducing you to a Switch Mode Power Supply (SMPS) at your level of knowledge is beyond comprehension. You should find another teacher before you hurt or injure yourself. Your teacher must be beyond incompetent. Good luck BTW.

Joined May 27, 2020
2
Hi. i need a diagram over an smps, the input set to 9V from an 9V battery to +5V/500mA and -5V/200mA on the output, and i use an mc34063a?
You can try using TPS54060 chip from Texas Instruments. Check the datasheet below, in Page 40 (Figure 64) you will find an application diagram where you can use the chip to split the rails and obtain positive and negative output voltages.

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Joined May 27, 2020
2

#### eltock

Joined Oct 29, 2020
9
I get it all. But it is important that it is a mc34063a says My teacher, All I need is det +/- output diagra.
I would like to use a mos
You didn't say there was a teacher involved, and you didn't post in Homework Help. His motivation for introducing you to a Switch Mode Power Supply (SMPS) at your level of knowledge is beyond comprehension. You should find another teacher before you hurt or injure yourself. Your teacher must be beyond incompetent. Good luck BTW.
Single question? Is it possible to Make buck-boost converter and an ext mosfet, with + and - on the outside?

#### Papabravo

Joined Feb 24, 2006
15,521
I have used similar one, at least I am familiar with the application, so if you have any question your welcome to ask.
Sure. How did you fabricate the transformer?