Двухполярный источник ±15V из Повербанка. Питание аналоговых схем. DC-DC XL6009
We connect an oscilloscope to the exit DC-DC converter, Sensitivity of 10 mV divisions, pulsation frequency 180 kHz. You can count which amplitude pulsations. Switch the oscilloscope to The output of our filter and with the same sensitivity oscilloscope We see that the pulsations have almost disappeared.
Now we can use This is stress To feed our some analog schemes. And of course a two -polar voltage relative to the middle point. Hello friends! This is the MBS Electronics channel. I am Oleg and my assistant electronic ROXY cat to power analog schemes on operating amplifiers, on transistors, some microphone amplifiers, Pre -Amps. A power source with low pulsation level, With, so to speak, a very clean tension.
Impulse power supplies that You can buy now In any store or order in China, Little for this is suitable for food analog schemes, because usually at the output of such impulse sources A very high level of pulsation. High -frequency interference, which Inevitably form at the output of a pulsed power source, just because of the principle of his work The weekend switches transistors of the power supply, this creates impulse interference. Usually laboratories that They are developing analog schemes, use linear power sources with ordinary transformers, with linear stabilizers stress, or, like an alternative, Quite expensive High -quality impulse sources With good filtering. In addition, for experiments with schemes on operating amplifiers most likely you need a source Food with two voltages relative to the average Points so -called Double -polar power source, This is usually a plus or minus 12 or plus or minus 15 volts. Of course, operating amplifiers can work with a single -polar nutrition, but it is, as it were, not very It is desirable for nutrition operations. Operating amplifiers are developed It is for use with two -polar power, and use operations in diagrams with one power source This is always a compromise between convenience and cheapness and quality.
I have an idea to do A small device in the form of the prefix to the usual pavorbank, which we use For the charge of our mobile phones. Voltage compound 5 volts from a pulsed source, which is PAVErbank. In double -polar voltage, say, plus or minus 15 volts with low pulsation level, which It would be suitable for powering small analogue schemes with low current consumption. Those who are watching the channel, I think, They know that I am very Like different analog schemes. Of course, in a row with digital technology There are videos on the channel About tube amplifiers, about Various microphone SAMPs, about Temra regulators.
I immediately want to ask everyone who looks Channel without subscription Subscribe to the channel, subscribe On our telegram Channel, you will find all links in the description. The first thing we need is to increase DC-DC converter. At the exit of Pavverbank we have only 5 volt, but we need tension up to 30 volts somewhere like that. I used this DC-DC raising converter Based on the XL609 chip. We connect the input to these contacts stress, but from these contacts remove the output increased voltage. We can have the input voltage in the range from 3 to 32 volts, and we can set the output voltage from 5 to 35 volts.
In this case, the input current of the microcircuit There may be up to 4 amperes. Many confuse it with an output current and Offended later that on 30 volts The microcircuit does not give out 4 amperes. The output current of the load will depend From how much voltage we will establish. The higher the voltage, the less There will be a maximum current. For my purposes, this does not matter at all. This thing will be designed for small Weighty currents for powerful analog schemes.
Therefore, the capabilities of the current on the current We are more than enough for us. Transformation efficiency up to 94 interest, that is, good efficiency. Here again, as well as with current, the more there will be the difference in the input and output voltage, the less efficiency will be converter. The output voltage can be adjusted Here is this blue, Multi -turning adjustment resistor. In my board, I soldered this tuning The resistor, instead of it, sold 4 into a fee.
We will solder the external A potentiometer that will be installed on the case so that you can It is convenient to adjust the voltage. To supply input voltage from PowerBank will use this Convenient USB Type-C connector. I also ordered it on AliExpress. The link will be in the description. Filter and converter of a single -polar voltage in the two -polard, assembled on Such a mock -up. Let's look at its fundamental scheme.
Voltage from the output of the DC-DC converter Submitted here for resistor r1 With a resistance of 1 Ohm. Resistor R1 and ceramic capacitor C1 form the first link of the input filter For trimming high -frequency interference. Inductivity L1, capacitor C2 and parallel to him capacitor C5 ceramic. This is the second link in the input Filter to suppress interference. Often the question arises, why in parallel an electrolytic capacitor who has Big container connect more Ceramic capacitor small capacity. Who someday in childhood sorted out electrolytic capacitor, remembers that inside there is aluminum foil, rolled into a roll, that is, into a coil, The electrolytic capacitor is enough High parasitic inductance, Therefore, he does not cut well High frequencies.
For this, parallel to electrolytic The condenser is usually turned on Ceramic capacitors small capacity. Here at the output of our device you you also see two electrolytic capacitor, in parallel to which two more ceramic Small capacity capacitor. The formation of artificial land or artificial average point for two -polar voltage produced using the scheme on operating amplifier and two transistors.
Actually, these transistors are needed simply to increase output power our scheme. We have a voltage divider from a resistor R2 and tuning resistor R3. In tuning resistor, we install At the connection point of resistors R2 and R3 The voltage is equal to half power voltages. Please note that our voltage divider It is also made by electrolytic capacitor C3 and ceramic capacitor C4 also to eliminate high -frequency interference in this point. This is a point of displacement operating room
amplifier and therefore it is very important here The quality of this very tension, so that there is no pulsations. The displacement voltage equal to half The supply voltage is supplied on non -inverting Entrance of the operating amplifier And accordingly on output of the operating amplifier We have it The same voltage equal to half power voltages. Further, this is stress Submitted to the base transistors and at the connection point imiters These transistors are formed The so -called Artificial average point Or can be called Virtual land. Our scheme Covered by loop negative feedback through the resistor R4, one kiloom on inverting Operating entrance amplifier. Respectively at the exit on the connector X4 we will always have half power voltages Regardless of the size of the input stress. For example, if we are coming We will connect some Large load, low resistance the load will be quite large current and we have tension asking for the outlet of the DC-DC converter, then on connector X4 anyway in any case will be half This, say, sagged stress. At all
This is very common Scheme for receiving double -polar voltage from single -polar. Naturally, I did not come up with it. Operating I wanted to use the amplifier LN358, but a set these microcircuits have not come yet me with Aliexpress, Something is delayed, so I installed NE5532. Well, in general in this scheme can be used Almost any operational amplifier. Transistors BD139 and BD140 are Medium transistors power, more powerful transistor In this scheme It makes no sense to put it. You can Put the Soviet
KT814 and KT815 should work, but bd139140 - they Better in parameters. Link to They will be in the description. Generally good transistors, Very cheap, They have good parameters and can be used in different radio amateur designs, in all sorts of amplifiers, in blocks nutrition and so on. This inductance reel on the swindle I took the ring from some old impulse power supply. Inductance She turned out to be
About 5 megeners. You can simply Win on the Amid the ring with a wire with a diameter, well Let's say 2 or 30 mm. The more inductance will be, the better. Or take it The coil is how I am from some old Impulsive. Tuning resistor I installed this one
It is better to install a multi -turn here tuning resistor, but I installed That's so ordinary. I installed the operating school on a panel when they come to me LM358, I am this NE5532 I will change to 358, and the NE5532 can be possible Use in some kind of audio schemes. 5532 is good little noisy operating amplifiers and, Probably, in this scheme, this Excessive. Compound Made like this with the reverse Sides of the board. IN
Mostly I used it myself Conclusions of radio components, They are quite long, and there Where was not enough long conclusions, I threw additional with jumper from wire. Actually, everything is how Usually on mock -ups. I am not a printed circuit board began to breed for this scheme, spend time. Everything works. The case printed On a 3D printer From the same transparent Petg plastic, from which we somehow did with you Audio -enclosure, which still works I have here on my columns. Corps model I have developed In the free FreeCAD version program Freecad Link. Lately Freecad has become enough
Good programs and developers have taken For him. And in fact for The development is simple some 3D models for 3D Printing Freecad to me SolidWorks completely replaced. And something in Freecad To do even more conveniently than in SolidWorks. Some things. The model is with us consists of two parts,
This is a box and a lid. When you Develop a 3D body model For some device, It is convenient to have models on hand also components that will install In this building. All printed circuit boards, some switches, LEDs, terminals. In Freecad you can store All these elements Separately, like separate model, And turn on if necessary, move In those places, where they should be. See I have here These are both boards. I'm on purpose Not lazy did so schematically very The models of these are all elements, but so that They are for the dimensions for sure corresponded to the originals. Then you are very
Easy and conveniently arrange the body your device. On the side you see three multi -colored terminals. These terminals are also designed in Freecad, printed on 3D printer. A little later I will show How they are arranged. There is a USB Type-C connector below and The cover of our box. It just closes, inserts There, how on such special elements And you don't need her Fix with any screws, in fact, She is so Holds well just at the expense friction. 3D model terminals. The basis of the terminal is Normal M4 screws,
Scands and nuts M4. At first I wanted to Buy factory terminals, but it was lazy on Radio market, therefore I decided to just print it There are on a 3D printer. First we pull out such a blank a certain diameter for a certain The length, then we do hexagonal neckline M4, then cut out through opening for a screw, Then we do this a semblance of a handle to conveniently There was this cooling Twist, make such a neckline, Then we create an array these cuts in circle, He is there inside me I made a chamfer, now I will turn off I turn on again To make the chamfer to be visible inside, To the printer it was convenient to print without support And from above too I am doing another rounding That's one. And all
Our terminal is ready. It's ready printed terminals, Initially, the plastic is like this Red and black And golden, I painted it acrylic paint. We insert a nut there, on M4 can be fixed her supergllers there and actually Everything, then you can set the cooling of frame. In fact Such cheap homemade terminals can be used in completely different DIY electronic devices.
This nut that fixes the clemus on the case, you need to tighten it very much, But right now with all my heart. We see now we have 24 volts at the exit, Regarding the minus. Let's try To adjust the tension. Minimum voltage somewhere about 5 volts and maximum what we have The maximum will be even more than 40 volts, but this at idle.
In principle, more than 30 volts To the maximum I don't It is necessary, so you can in the future Probably limit Adjustment range. Well, for now Let it be as it is. Now I am exposing 30 volts To the maximum on output. We see that in the middle We have 15 volts. Everything is fine. Temember You can change
voltage at the middle point, then There is to unbalance you can, or adjust it so that there is exactly half power voltages. In those schemes, which we will feed from our device and which needs bipolar Nutrition, that's just The middle point will play the role of the Earth, Virtual land. The trick is that The voltage is relatively this virtual land, that is Plus a minus some kind stress, it will also be regulated Here general regulator and what We would not put here, we always have at the middle point there will be exactly half of the general stress. If
measure about our virtual Earth, that is relative to the middle point, then just We get here in this case plus-12 and minus-12. Let's We will connect the oscilloscope and see What are ours turned out pulsations at the entrance and what are the output our scheme. Now I have connected Oscillograph on The output of the DC-DC converter And we see such pulsations. That's what Priote, so to speak, with
output of a pulsed converter. On the oscilloscope there is a sensitivity of 10 mV by division, accordingly, you can calculate This is somewhere, probably in the area of 100 MV pulsation. Such stress Almost unacceptable for food, for example, Microphone amplifier schemes. This is all
will penetrate our analog Components. OscillOgrah shows that Pulsation frequency about 180 kHz, although in the passport On the microcircuit It is written that the frequency of transformation is 400 kHz. Let's switch the oscilloscope to the exit our filter is here, on the maximum Let's see the tension. We see that we have practically
pulsations have disappeared, they are less 10 MV. On this There are practically an oscilloscope Not visible. I think, That this is a very good result. Of course, if load this scheme in some low -level load, then pulsations will increase, but nevertheless. We switch back to the output DC-DC converter and here again we see these high -frequency interference. 180 kHz
This is the main frequency of these Pulsations, but spectrum they can stretch up to several megagers. Harmonics They can go there, Create interferes. At the exit, even here relative to the average point, We also have absolutely pure stress without any noticeable Pulsations. You can try As a small one load to exit the load A resistor for 100 Ohm, for example. Here I am now I connect and also do not I see some kind of interference. Our The device works, you can close cover, so here in the way it closes, tight Holds all The device is ready. Can experiment with
analog schemes. Leave yours Comments, put your likes or dizlaiki, write What do you think about this power supply, Friends. You will find all links in the description. I say goodbye to you. My electronic cat Roxy It also says goodbye to you. Goodbye, All the best. Until the next meetings!
2025-04-13 05:23
