best regards and special thanks ❤️

exactly, no information on an information video, and why are they always at the top of the lists?

@@stephenhanson3309 Yeah... I guess this (YT) _IS_ at the end of the day, mostly private citizens doing what they can to inform, often without any experience in teaching. I firmly believe that IF you have any kind of a gift for teaching, you can clearly teach anything that you can actually do... but there are too many putting up videos that _THEY_ understand... but are totally ignorant of how it looks and sounds to the learner. It is VERY annoying, when we watchers have arrived precisely because we want to learn something... only to be confronted with a low-res, garbled, illogical (and often spoken in a thick accent) account... which at best can be consigned to the "interesting, but HTAF did he DO that" category. My vote is DO NOT POST... until you can give a clear account of what you are doing, without apologies or obfuscation. This bloke is better than most, hence my encouragement.

best regards and most welcome

SAME WITH ME SALAM FROM INDONESIA

most welcome

So nice of you. stay blesed

Hi, Haseeb. Some time has passed and I have learned some things. In answer to my own question regarding using a potentiometer to make a variable power supply, I have written some notes... Laptop Brick to Variable PSU Conversion These conversions are based on finding the TL431 voltage reference and replacing the primary resistor on its voltage setting resistor divider with a potentiometer. The maximum output voltage of the device is reached, when the output chopper transformer begins to sing. This is determined through experimentation. However, a reasonable estimate of the needed potentiometer value to reach a desired maximum voltage might be a linear multiple of the value of the primary resistor on its voltage setting resistor divider. Example: Given that 1) the original output voltage of the device is 19V, 2) the voltage setting resistor divider for the TL431 consists of say R1 = 10K and R2 = 750R, 3) the output chopper transformer does not sing at the desired new maximum voltage output and 4) the voltage rating of the original output cap(s) is 25V... For a desired new output maximum voltage of 30V... 19 Volts/10K Ohms x 30 Volts/XK Ohms 19 * X = 10 * 30 19X = 300 X = 300/19 X = 15K789 Ohms (the nearest [lower] potentiometer value is likely 15K) and the voltage rating of the output cap(s) should be raised above 30V, to say 50V, to add some needed headroom. Caveats 1) The original output caps must be replaced with the same uF, but at the new maximum voltage output rating, plus some headroom. If the bleeder resistor that is connected in parallel to the output capacitor begins to heat up, you will have to increase its wattage, as well. 2) The total output wattage capability of the PSU cannot change. Therefore, as the voltage output capability goes up, the amperage output rating goes down. As a current limiting circuit has not been included in this conversion, the operator of the PSU must manually manage the current draw upon the device. Or, a current limiting circuit could be contrived. 3) Regardless of the desired amount for the new voltage output, the new voltage output should not surpass the point where the output chopper transformer begins to sing. 4) The original R2 of the voltage setting resistor divider for the TL431 should be left in place and its value should not be changed. It sets the lowest voltage level that the device can reach and is rated to maintain the minimum voltage needed to run the device. *** As always, I do not take any responsibility for any consequences from using any information that I provide. I am not an electrical engineer and my statements could be incorrect. Electricity can hurt you, or even kill you (easily.) Proceed at your own peril. *** Haseeb, I am very tired; my health robs my sleep. Please proof my notes to make sure that what I said is correct and that I have worded it clearly. I appreciate this help. Additionally, there is a lot of interest in adding a constant current limiting circuit to these power supplies, when they have been upgraded with a potentiometer to be adjustable. Please design such a circuit for us and show us where to insert it into the original device. I look forward to that video, please and thank you!

Thanks and welcome

So nice of you. please accept my best regards

best regards 💕

best regards

Thanks and welcome aap ne mera urdu channel (HASEEB ELECTRONICS URDU) visit kia? agr nahi to ( *haseeb electronics urdu* ) check kr lein

best regards and special thanks

thanks a lot dear

@@HaseebElectronics I appreciate your highly informed reply. Thank you Sir. I most say that you have added to my knowledge bank immensely. I am grateful once again.

Most welcome best regards dear

@@HaseebElectronics the current regulator you mention is easy to build ? Or better to buy it ? I need to charge a 12v battery at 0.8A but i don 't know how to limit the amps but keeping voltage at 13.8v. Thanks.

Sorry it's SG6858 IN PLACE OF SG6848..

please check RCD snubber circuit, check TL431 or related circuit Optocoupler

it is my pleasure

you are right, when the voltage are reduced, at that time it is less risky,

@@HaseebElectronics I see, so replacing an existing resistor with a lower resistor will allow more current and lower voltage (because wattage output remains the same). I can calculate this using the ohm's law.

thanks a lot sir

Original it is 12V

might be there is a over voltage protection. you have to find and disable the over voltage protection first then you can adjust the output

wa alaikum salaam brother

to increase voltage from 12 to 27, it will very difficult. and the regulation feature may not be achieved, you can disassemble transformer and increase output winding turns. please check video number 390

i think the bleeder resistor is heating up. that is connected in parallel t the output capacitor you have to increase its value as well with considering wattage

@@HaseebElectronics Thanks for replying. Where is bleeder resistor?

if that over voltage protection and it is coupled via optocoupler, you can disable it from this optocoupler

​@@HaseebElectronicsi did it and it works thanks alot my friend!

if it touching to lower limit then locate vcc pin and a resistance in series with rectifier diode at auxiliary winding if there is a resistance, remove it it will allow to give more lower level threshold

yes dear if we adjust at charging threshold, it can be used

@@HaseebElectronics thanks a lot i tried and it works, and it even charge my phone faster than before

please define the term "RUMBLE CHANNEL" because I am weak in english vocabulary, please

@@HaseebElectronics There is a new Video Platform to Post video's and monetize.. It is called Rumble.com

is ke secondary section me koi component problem he. may be some capacitor rectifier feedback circuit check kr lein vcc capacitor check kr lein main dc capacitor ko check kr lein

Ok g jazakallah. Thanks for the quick response

i am from Pakistan but now in Jordan

@@HaseebElectronics Great bro

Ji bhai Urdu bool sakta hoon aur bolta bhi hoon aap meri video urdu me dekhney keliey mere urdu channel (haseeb electronics urdu) ko dekhein. wahaan ye sab videos urdu me hein

جی پیارے بھاءی میں اردو میں ویڈیوز اپنے اردو چینل (حسیب الیکٹرونکس اردو) پر اپ لوڈ کرتا ہوں۔ وہاں ساری یہ ساری ویڈیوز اردو زبان میں ہوتی ہیں۔ جو کہ صرف میں اپنے پاکستانی اور انڈین دوستوں کے لءے بناتا ہوں۔

best regards