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Regulated power supply, such as LBP



I decided to redo my laboratory power supply. Well, as a laboratory, rather, an adjustable power supply. I have already assembled a similar one, but for some reasons I dismantled it.

I decided to collect an unusual and not taking up much space power supply. It is unusual in that it will be suspended under a hinged shelf. I chose the box from the old Huawei modem with the case.

Accessories:

- housing from the modem;
- lowering module;
- adjustment module;
- toggle switch;
- adjustment resistors;
- handles on resistors;
- voltammeter;
- terminals;
- instruments.

About accessories.

I have a case box from an obsolete and tattered modem. It is quite compact. There are vents. There is a very convenient niche for the toggle switch.

Lowering board from China. It is compact, just under my body. I squeezed more than 5A from her. Apparently this is its limit value, the nominal is kind of like 4A. The output voltage is 24V, my version produces 23.8V.

Adjustable module made in China. My version adjusts from 1.26 volts. There are refinement options on the Internet that allow you to adjust from zero. I don’t really need this, it will suit such a minimum voltage. Maximum output voltage, almost repeats the input voltage.

I will switch the mains voltage with the T3 toggle switch. I tumbled the tumblers.

Trimmer resistors of the adjustment module, replace, adjusting.
Both at 10 kOhm. Resistor handles are also needed. Initially, I took large ones, but they do not fit on the case, replacing a smaller one.

Voltammeter from the Middle Kingdom. The accuracy is pretty good, as a last resort there are tuning resistors on the back side.

Terminals from the old measuring device, I do not remember the exact model. They are quite strong and just found a different color.

Assembly.

On the front panel we make markings for: a multimeter, terminals and resistors. Everything is very simply cut and drilled. I began to cut with a drill, but the plastic melted, even at low speed. Dorezal clerical knife.

I wonder where the modules will be. I mark the holes, drill and screw the boards. Adjusting resistors soldered and soldered wires. The voltage of a pair of wires, the current three wires.

Install the adjustment resistors. I put the pens, found a smaller size. I solder wires to the resistors. I connected the wires with a thread so that they would not be confused. I connected the power board and the adjustment board with wires.

You can power a multimeter from the output of the power board, but I will power it through a separate stabilizer. I will collect it on TL431. You can calculate the output voltage on the calculator.

I fasten the output wires to the adjustment plate. I took the output wires from the old PSU, they already had lugs. I screw to the terminals. I bring out wires with connectors to a multimeter. Glue stabilizer with glue gun. In parallel to the voltage regulation resistor, a 27kΩ resistor was soldered. It seemed to me that the adjustment became smoother.

I almost forgot about the wiring of the toggle switch. I connect both input wires through the toggle switch. I will not install the network connector. Constantly losing the detachable wire, set the wire to constant.

I install a multimeter, twist the case. It was possible to squeeze more than 5A from the block, but this is the limit and not for long. About 4A gives out stably.

A significant minus, judging by the description of such blocks, is the large ripple at the output. I currently do not have an oscilloscope, I will study this issue later. There are plenty of options for reducing ripple on the Internet.

I got such a power supply. Apparently it is noticeable that the block is assembled upside down. The lid of the case is its bottom. The following photo answers this question.


Assembly video available:

8.2
8.4
8.4

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36 comments
Evgeny Potapov
I have a simple soldering iron with (I don’t even remember when) the assembled simplest regulator on a pair of thyristors, no galvanic isolation. I haven’t burned a single field yet, haven’t punched anyone ... Ah, yes! Forgot - a sting - ceramics ... ;-)
Well yes...
P.S. Thank God, this is only in jokes ... But, I was in Odessa - they often park on the sidewalks ... I can’t understand if this is allowed in the Ukrainian Rules ?? Because the cops travel around the city ... They see. But they do not call tow trucks and do not fine ...
They told me that you can’t even drive along the sidewalks! Brazenly lying !!!
We have only one prohibition sign - a concrete block across the road. All the others mean that you may have to pay for the fare.
Can! Verified in practice !!! )))))) ... I have, in general, "Coffee without a cigarette - money down the drain!"))))
P.S. They told me that you can’t even drive along the sidewalks! Brazenly lying !!! I specially tried it - CAN! At least I did it the first time.))))
Valery
I SMOKED A SECOND, SIPED COFFEE
Categorically NIZZZA! stop xaxa
We all know well what to drink, smoke, drink coffee in liters, etc., etc. smoke

Already laughed ... The fact is that now in my basement I decided to take a break from work, turned on the computer, lit up a kettle, drank a can of beer, then made a strong COFFEE, lay down on the sofa in front of the computer (I have it like that) )), I SMOKED THE SECOND, DIPPED THE COFFEE and .... read this post! punish
Valery
Or maybe I'm wrong? ... Maybe, well, her - this denouement! ...
We all know well that drinking, smoking, drinking coffee in liters, etc., etc., is very harmful, we also know about a healthy lifestyle, and so what? smoke
And galvanic isolation, if you do not solder the field and do not climb the soldering iron into the network, is not such a mandatory factor.

Oh, damn it ... And I, except for the holes in the copper pots, did not solder anything.So what? ... In vain, did he fool around, did the denouement ...?
There, the tavarisch says that nnada is abisitative! )))))
Pulse block for tuning sensitive analog equipment, H-Fi, Hi-End - yes, as a rule, unacceptable. To configure the power supply, charger, simple automation - why not?
And galvanic isolation, if you do not solder the field and do not climb the soldering iron into the network, is not such a mandatory factor. Yes, it is safer, yes - it is more correct, yes - it is more reliable, there is no need to be distracted by additional actions, but in order to solder a fallen off power cord, it is absolutely not necessary.
And here it’s not a pro, here are friends ... When I need to solder something in the kitchen, of course, the first thing I think about is how to first make galvanic isolation for the soldering iron!))))) ... But here , the rest during this time simply solder what they need, hide the soldering iron back in the mezzanine and, like a little, they laugh at me obi-and-idnenko! ))))).
And I’m still sitting and thinking about the denouement ... And they have everything soldered and they have gone to work with others ...
... So I think: Or maybe I'm wrong? ... Maybe, well, her - this denouement! ... Anyway, I don’t get a soldering iron every six months ...
Guest Sandro
Impulse BP as a repair equipment is not professional. As well as soldering irons without galvanic isolation from the network. Well honestly. When will this chaos stop already?
Not Rabinovich, but Ivanov, not in the lottery, but in cards, not Volga, but 100 rubles, he did not win, but lost.
Alexander Osipov
ANTI-GRAVITY WITH ACTION;)
however, the same design was assembled, but put it into the casing with the advantage of adding mods from DD1502 to receive a two-channel source. And however, I got the current up to 9A on the same channel, but with the difference that the IIP is at maximum 24v * 6A, and the indicators are powered by charging the cell and the second indicator is powered by the first through an isolated DC5v-DC5v ...
Guest Andrey
If you know how to cook, you may also have been to welding forums. So this forum site is the same. People gathered here who have succeeded in something. Everyone soars on his wings.
By the way, to dig a ditch - why? And what, from the fly, or what?
Arnold
I can dig a ditch, plaster the wall, rearrange the wheel, weld a stainless steel barrel with an electrode
But I can’t
Only for all the time have I never needed such crap
And if and when needed, I will hire you! smile
Quote: Arnold
... brew a stainless steel barrel with an electrode ...
But I don’t need to know how to do it, but I’ll need it - welders will arrive from three sides, which I once repaired, modernized and helped. Also with a ditch and with a mash.
And you will not say, my dear, what is the stupidity of the appliance?
Arnold
I wonder how smart everyone is here. I can dig a ditch, plaster the wall, sort the wheel, weld a stainless steel barrel with an electrode. And then there are such monsters, such technical solutions. Respect! Only for all the time have I never needed such crap. Neither on the table nor on under the table, next to the bottle with mash. And not needed. And yet. I respect our president, and he does not care how I respect him. Is this my respect for me? No, it’s not necessary, like this device is stupid.
Author
Kind!
I have a 24 volt source with less current.
I think it will survive without a fan.
Good afternoon!

I have almost the same power supply (with the same step-down Chinese module XL4016). Truly a workhorse for loads that can survive clutter and ripple.
Of the improvements, I can suggest replacing the voltage regulation potentiometer with a multi-turn one, and the fan for cooling the lowering module will be very useful at a current of more than 4-5A
Such a Chinese amp-voltmeter is in my charger for a car battery. Works great with a load of 5.5A.
As an option for smooth adjustment of output. voltage, you can put a second regulator (a resistor connected through resistance to the main), as is done in many prof. laboratory BP. After all, you have digital control.
About the main regulator. I saw what you set. In the telly of the times of the USSR, not the contact of the engine led to rustling. In the PSU with such output data, the connected circuit will fly out. Put the PPZ, they, of course, dispersed in the precious metal, but not all.
I advise you to put an adjustment resistor of linear characteristic (A), it costs B. Therefore, you soldered the resistor in parallel, the adjustment became smoother ... That's right. Clearly, the handle under it will have to look for another.
Do not squeeze 5 A x 24 V for a long time !!!, later I will write how to add a simple thermal protection with self-restoration to your PSU.
Author
Right From the table to the power supply unit, approximately 30 cm.
Author
Quote: ino53
Not bad.
That the 1978 tumbler (probably older than the author smile ) - it is respectful, but the adjusting h-ka of the second variable - type B - is not good, we need A.
As for space saving - I have a panel under the shelf about 70 * 155 with a volt- and ammeter, an alternator and an LED, the cable goes under the table, the weekend and network wires emerge from the gap between the table and the wall. What's under the table - I’m silent.


The toggle switch is probably the most reliable element))
The resistor tweaked a little, but you need a multi-turn.
Author
I took this device from the old PSU. There, of course, he did not work for a long time, but he kept the current at 3 amperes well. A lot of videos online with such tidy devices, very few complaints. Complain about the accuracy, I also have resistors at the limit. He lies at 50 mA and 80 mV, with a current of 3.8 amperes and a voltage of 11.5 volts.
ino53
adjusting x-ka of the second variable - type B - is not good, we need A.
I also encountered uneven adjustment, but the author somewhat “straightened” the characteristic:
In parallel with the voltage regulation resistor, a 27kΩ resistor was soldered
In principle, the right decision, we must try in your BP! scratch
Guest Gennady
Everything is fine, only the Chinese ammeter is the weak link in this homemade product, no more than 2a, and for a short time.
I generally refused electronic ammeters, the Chinese declared amps do not correspond
realities --- theoretically yes - in fact, Chinese fairy tales. Here you do, customize, after an hour of work
the ammeter passed away - and that’s it - we need to be smart and find a place for our dial gauge.
For beauty only.
Not bad.
That the 1978 tumbler (probably older than the author smile ) - it is respected, but the adjusting h-ka of the second variable - type B - is not good, we need A.
As for space saving - I have a panel under the shelf about 70 * 155 with a volt- and ammeter, an alternator and an LED, the cable goes under the table, the weekend and network wires emerge from the gap between the table and the wall. What's under the table - I’m silent.
I read it for a long time, but I remembered that he had a whole bunch of broken alarms.
There was such a character - Carlson (yes, who lives on the roof), in his house everything was hanging on nails driven into the wall.“So everything I need is in plain sight,” he explained. Here, the device does not even take up space on the shelf, because it is fixed from the bottom, as I understand it.
Author
I will also be finalizing, after temporary tests.
LED, a good idea, you need to think.
In vain did not bring the two-color indicator LED to the front panel, it is very convenient when charging batteries. It shows the stabilization mode - current or voltage.
Author
Ripples at a load of 4 amperes and a voltage of 11.8 volts amounted to 450 mV. It is necessary to increase the capacity at the input of the adjustable module. I will try to unsubscribe about the experiment.
Here it is, a way to clear the table in the workshop - everything is up!

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