Great investigation. I expect ESR of the output capacitor on the board to play a role too. A good board to have since most converters use hiccup mode protection - so not really CC even though the sellers often state the boards to have proper CC mode.
Good day Sir, I was wondering if I may ask, are you able to fit this unit to, say, a 12V 2A power supply and run the output at 24V 0.63A? I understand it is a buck converter, I thought perhaps it might operate as a buck-boost? Many thanks!
Hello! A buck converter can only step down. A boost converter can only step up. Only a buck-boost converter can do both. XL4014 is a just a buck converter IC. So, the answer is no.
Just bought a couple of these and turning the screws does absolutely nothing. Output voltage is the same as input Would think maybe one was a dud, damaged in post, but both of them?
The input voltage must be about 2V higher than the output voltage, otherwise input and output are nearly the same. Also, the precision trimmers need to be turned 10 times for the full range. Also, the precision trimmers give no feedback, if the mechanical slider inside is at one end of the range.
@@sirflooz Thanks. My input voltage is actually 5 V and I want to step down to 4V. I actually turned it about 20 times to get the voltage to start dropping and managed to get it down to 4V, But now the current limit does nothing. One board just makes a crackling noise in my bench supply when I short the output. The other board just reads 3 amps output, even though my supply is set to 1 amp.
@@ArcanePath360 Now you know the precision trimmers! The CC circuit of the module is supplied by a 78L05 5V voltage regulator, so your input voltage must be 2V higher = about 7V to operate. Crackling sound could be caused by unwanted oscillations, as I had them in my video. Have fun.
@@sirflooz So it is like an Arduino, where you need to supply at least 7V to the barrel jack to get the regulated 5V? It seems like the more I learn, the less I know. What's weird is the LED shows it is limiting current when I turn it all the way down, but a motor still shows the same output and runs the same... Wait... OMG I just tried it with my bench supply set to 7V and you are right! For the first time I got the current reducing function to work! Thanks a bunch man!
Hola ! Crees que se pueden modificar los parametros de los BMS de las baterias de litio ( li-ion , LFP...etc ) ? Todos permiten cargar y descargar demasiado las baterias y resulta que las degrada rapidamente , por ejemplo las li-ion es mejor que corte la carga/descarga a 4-3,5V , las lifepo4 que las cargue hasta 3,5V y descargue hasta 3V , o hacer que sea regulable De serie incluso superan los parametros maximos de las baterias! Seria muu util explicar esso para mucha gente . Gracias !!!
Saludos amigo disculpa las molestias yo compre ese mismo modulo pero se me hizo un corto y se me quemo el circuito de 4 pines que alimenta los ice y la verdad al quemarse no se su valor o su codigo para reemplazarlo no se si talvez me puedas ayudar diciendome que circuito es y su valor grasias
The input current depends on the output current. If you look on fig.6 of the datasheet, you see that at 8V input, the best efficiency is at about 0.6A at 5V output. For other input voltages see the other colored curves. For an output voltage of 12V, look on fig.8. I hope this will help you. Please understand that I cannot give further advice.
That 100~105 hz ripple could be due to ripple from your power supply. Do you live where your mains frequency is 50 Hz? If so, that's more than likely mains ripple from the bridge rectifier inside your power supply you used for testing the board. It may not have been the buck regulator entirely. Great video btw as well.
Welcome to the wonderful hobby of electronics. Regarding the capacitor, the value depends on the current you draw. 680uF is a good starting point. A lower value might work, a higher value might be necessary - test it. But make sure to always use low ESR capacitors here (the market provides normal and low-ESR electrolytics, Tantal is usually always lowESR, Ceramic capacitors depends on type). I hope this helps. The web provides also good notes about low ESR on SMPS (switch mode power supply). Stay curious.
No, you normally do not need to add that capacitor, and more often, adding one is needed for higher output, say 2A or above, IF your load can't tolerate the resultant ripple. I would just ignore the example in the video because there are other options for less expensive and smaller, lighter weight, modules to regulate a mere 90mA.
The XL4015 IC datasheet states +8 to +36V DC input possible, BUT you need to have a look what the manufacturer of the module states regarding the max. input voltage. For example the input capacitor must be able to withstand the input voltage.
Your temperature drift test doesn't make much sense, because not only are you cooling to an extreme that won't normally be seen (that low) but also because you were cooling the wrong chip, as the LM358 doesn't pass the current, isn't going to heat up nearly as much as the XL4015, or the diode which also has temperature increase and drift based on current. Even so, I can appreciate cooling it to whatever ambient temp it will actually be used in, in order to most accurately adjust it before use.
Thanks for dropping a comment! But please have a detailed look on the schematic of the module (can be found on the net). There you see, that the XL4015 has only a voltage regulator, while the OPAMP is used to sense the current and to generate a corresponding control voltage for the XL4015 to add the current limiting function. Therefore my temperature drift test makes sense. The cold temperature is good to show the trend of the error. Of course it is no scientific experiment. Let's have fun in electronics!
New video about the WS2812b RGB LEDs released: ruclips.net/video/BY5IZT0W8lQ/видео.html
Great investigation. I expect ESR of the output capacitor on the board to play a role too. A good board to have since most converters use hiccup mode protection - so not really CC even though the sellers often state the boards to have proper CC mode.
True, low ESR capacitors are essential when it comes to SMPS.
Thanks for the video, I had fun watching what I already knew about these crap modules, THANK YOU! :)
really good video. Thank you mr, also for fundamental information.
i subbed.
You are welcome! :)
Very interesting video and modification 👍 and for that 10/10 but I can't refrain from commenting on the method of removing this resistor 😭😱 hehe ;)
Thanks for commenting! Yes, if a part is glued with heat resistant glue, brute force method is my method. Hehe... ;)
Quite thorough insights. How can you tell if the cap is low ESR just by looking at it?
Appreciated. Well, I have measured it on an ESR meter.
Good day Sir, I was wondering if I may ask, are you able to fit this unit to, say, a 12V 2A power supply and run the output at 24V 0.63A? I understand it is a buck converter, I thought perhaps it might operate as a buck-boost? Many thanks!
Hello! A buck converter can only step down. A boost converter can only step up. Only a buck-boost converter can do both. XL4014 is a just a buck converter IC. So, the answer is no.
Just bought a couple of these and turning the screws does absolutely nothing. Output voltage is the same as input
Would think maybe one was a dud, damaged in post, but both of them?
The input voltage must be about 2V higher than the output voltage, otherwise input and output are nearly the same. Also, the precision trimmers need to be turned 10 times for the full range. Also, the precision trimmers give no feedback, if the mechanical slider inside is at one end of the range.
@@sirflooz Thanks. My input voltage is actually 5 V and I want to step down to 4V. I actually turned it about 20 times to get the voltage to start dropping and managed to get it down to 4V, But now the current limit does nothing. One board just makes a crackling noise in my bench supply when I short the output. The other board just reads 3 amps output, even though my supply is set to 1 amp.
@@ArcanePath360 Now you know the precision trimmers! The CC circuit of the module is supplied by a 78L05 5V voltage regulator, so your input voltage must be 2V higher = about 7V to operate. Crackling sound could be caused by unwanted oscillations, as I had them in my video. Have fun.
@@sirflooz So it is like an Arduino, where you need to supply at least 7V to the barrel jack to get the regulated 5V? It seems like the more I learn, the less I know. What's weird is the LED shows it is limiting current when I turn it all the way down, but a motor still shows the same output and runs the same... Wait... OMG I just tried it with my bench supply set to 7V and you are right! For the first time I got the current reducing function to work! Thanks a bunch man!
@@ArcanePath360 You are welcome. Keep digging into electronics. It not always easy, but a lot of fun!
Hola ! Crees que se pueden modificar los parametros de los BMS de las baterias de litio ( li-ion , LFP...etc ) ? Todos permiten cargar y descargar demasiado las baterias y resulta que las degrada rapidamente , por ejemplo las li-ion es mejor que corte la carga/descarga a 4-3,5V , las lifepo4 que las cargue hasta 3,5V y descargue hasta 3V , o hacer que sea regulable
De serie incluso superan los parametros maximos de las baterias! Seria muu util explicar esso para mucha gente . Gracias !!!
Sorry, I don't offer free engineering services.
Saludos amigo disculpa las molestias yo compre ese mismo modulo pero se me hizo un corto y se me quemo el circuito de 4 pines que alimenta los ice y la verdad al quemarse no se su valor o su codigo para reemplazarlo no se si talvez me puedas ayudar diciendome que circuito es y su valor grasias
What's the maximum input current for the XL4015? And what is the ideal input current?
That should be in the data sheet of the XL4015.
@@sirflooz It only has the input voltage and output voltage and current.
The input current depends on the output current. If you look on fig.6 of the datasheet, you see that at 8V input, the best efficiency is at about 0.6A at 5V output. For other input voltages see the other colored curves. For an output voltage of 12V, look on fig.8.
I hope this will help you. Please understand that I cannot give further advice.
@@sirflooz Thanks for the advice.
That 100~105 hz ripple could be due to ripple from your power supply. Do you live where your mains frequency is 50 Hz? If so, that's more than likely mains ripple from the bridge rectifier inside your power supply you used for testing the board. It may not have been the buck regulator entirely. Great video btw as well.
A good point! But I think I used a switched mode power supply to supply the board. Thank you!
I'm just beginner. So should I add 680uf from now on if I need to connect this xl4015 to any device?
Welcome to the wonderful hobby of electronics. Regarding the capacitor, the value depends on the current you draw. 680uF is a good starting point. A lower value might work, a higher value might be necessary - test it. But make sure to always use low ESR capacitors here (the market provides normal and low-ESR electrolytics, Tantal is usually always lowESR, Ceramic capacitors depends on type). I hope this helps. The web provides also good notes about low ESR on SMPS (switch mode power supply). Stay curious.
@@sirflooz Thank you.
No, you normally do not need to add that capacitor, and more often, adding one is needed for higher output, say 2A or above, IF your load can't tolerate the resultant ripple.
I would just ignore the example in the video because there are other options for less expensive and smaller, lighter weight, modules to regulate a mere 90mA.
@@stinkycheese804 Thank you for your advice.
If I give 24v 3amp input in this module the IC will not heat na
Try 24V in and 1.5V 3A out if you want to have a heating side effect ;)
Can i use 32v as input?
Is it safe?
The XL4015 IC datasheet states +8 to +36V DC input possible, BUT you need to have a look what the manufacturer of the module states regarding the max. input voltage. For example the input capacitor must be able to withstand the input voltage.
Your temperature drift test doesn't make much sense, because not only are you cooling to an extreme that won't normally be seen (that low) but also because you were cooling the wrong chip, as the LM358 doesn't pass the current, isn't going to heat up nearly as much as the XL4015, or the diode which also has temperature increase and drift based on current. Even so, I can appreciate cooling it to whatever ambient temp it will actually be used in, in order to most accurately adjust it before use.
Thanks for dropping a comment! But please have a detailed look on the schematic of the module (can be found on the net). There you see, that the XL4015 has only a voltage regulator, while the OPAMP is used to sense the current and to generate a corresponding control voltage for the XL4015 to add the current limiting function. Therefore my temperature drift test makes sense. The cold temperature is good to show the trend of the error. Of course it is no scientific experiment. Let's have fun in electronics!
These cheap DC-DC converter board are so badly designed it is INSANE!!!!!!!!!!!!!!!!! Yep output filtering is crap, but so is the CC feedback loop.