**Understanding Buck Converters: A Guide**
In today's world of technology, power sources are becoming increasingly important, and one efficient way to manage them is through the use of buck converters. These devices can step down voltage while maintaining a high efficiency, making them ideal for applications where power consumption is crucial.
To achieve this efficiency, buck converters use a specialized type of power supply called a switched-mode power supply (SMPS). For demonstration purposes, we'll be using an Arduino Nano to switch the output pins on and off rapidly using the PWM function. By setting the value to 127, we create a square wave that's 50% duty cycle.
When measured with a multimeter, it shows that the voltage has been successfully stepped down from 5 volts to 2.5 volts. This method is effective for undemanding components like LEDs, but for higher voltages and bigger current draws, an upgrade to a P-channel MOSFETs is necessary. By connecting 12 volts to source, a 10 kilo-ohm pull-up resistor between gate and source, and hooking up the PWM signal to the loads, we can control the brightness of a small light bulb.
However, this switched voltage still has high voltage peaks that can destroy sensitive electronics. To address this issue, we add a 100 micro Henry inductor in series with the loads, which stores energy in an electromagnetic field and allows the current to flow properly when the switch opens.
Unfortunately, this setup results in massive voltage spikes at the switch, which is why we add a Schottky diode below forward voltage to create a complete loop for the current to flow. Although it improves the situation, the resulting current flow is still far from steady.
To further improve this, we need to increase the frequency of the PWM signal, which is currently around 976 Hertz. By changing the prescaler in our sketch, we achieve a frequency of 62.5 kilo Hertz, allowing the energy storage capacity of the inductor to smooth out the current flow quite a bit.
This high-frequency switching is also why switched-mode power supplies usually use a high frequency to keep energy storage components small. To complete our design, we add a 47 micro farad capacitor on the outputs to smooth out the voltage and achieve an efficiency of 67% with our light bulb at 5 volts.
While this setup works well for smaller loads like LEDs, it's not ideal for larger loads that require a more stable output voltage. To address this issue, we need to use a voltage divider to provide feedback to the control system, which will adjust the duty cycle and maintain a steady output voltage regardless of the load attached.
For those who prefer a simpler approach, there is an adjustable version of the -576 simple switch IC that has built-in feedback resistors and only requires 4 additional parts to build up a complete buck converter. Following some basic rules for recreating the schematic – keeping all parts close together and creating fixed order traces – we can have our circuit working flawlessly in just 10 minutes.
This adjustable version of the -576 simple switch IC is highly recommended, as it allows you to add your own feedback resistors or potentiometer to create an adjustable output voltage. With this knowledge, you now understand how to step down voltages efficiently using a buck converter and can replicate this process in your own projects.
By using these techniques, you can achieve high efficiency and stable output voltages in your power supply designs, making them ideal for various applications.
WEBVTTKind: captionsLanguage: enlet's say you just got a new awesome electronic module that requires five folds in order to work but all you have is a 12-volt power source the easiest solution would be to use a lm7805 voltage regulator with an input and output capacitor to step down 12 volts to 5 volts but if we measure the input and output power we can see that the efficiency is quite low and gets even worse with higher input voltages because the regulator is basically a variable resistor that converts the excess power into heats which is not recommended when the power source is a battery to reach a higher efficiency though we can use the so-called buck converter this one is very small has an adjustable output voltage doesn't cost much and also reaches a decent efficiency but how do these converters work and can we even build one by ourselves let's find it out a buck converter is a kind of SMPS or switched-mode power supply as an example I will use naught we know Nano which can switch its output pins on and off rapidly whippets pwm function here I use the value 127 which creates a square wave will be due disciple of 50% if I now measure the voltage with my multimeter it already tells me that we successfully step-down or 5 volts to 2.5 volts because it measures the average and for undemanding components like LEDs this method already does a trick but in order to control higher voltages and bigger current draws we need to upgrade the switch to a p-channel MOSFETs by hooking up 12 volts to source a 10 kilo ohm pull-up resistor between gate and source gate also to the PWM signal and going to the loads I condemn the small light bulb and by connecting a potentiometer to analog inputs and adjusting the coder pits I can also control the duty cycle and thus increase or decrease the average boot and brightness of the bulb but our switched voltage still has high voltage Peaks which will destroy sensible five-fold electronics so we have to get rid of them to do that I firstly added 100 micro Henry inductor in series to the loads this way the current cannot rise instantly because a part of the energy is stored in the electromagnetic field of the coil and once the switch opens the electromagnetic field collapses and should pump a current through the loads which it does do properly instead we get those massive voltage spikes at the switch which is not a surprise since there is no complete loop in which the current could flow and thousand electron access occurs that is why I added a Schottky diodes were below forward voltage to the circuits so that current can flow when the switch is open but the resulting current flow is still far away from a steady value to further improve that we need to increase the frequency of the PWM signal which is right now around 976 Hertz I simply change the prescaler in my sketch uploaded it and promptly got a frequency of sixty-two point five kilo Hertz with such a short off time the energy storage capacity of the inductor is now enough to smooth out the current flow quite a bit that is also the reason why switched mode power supplies usually use a high frequency in order to keep energy storage components small all that was left to do but my design was adding a 47 micro farad capacitor on the outputs to smooth out the voltage and the buck converter was complete and reach the efficiency year of 67 percent with my light bulb at 5 volts which is not terrible but once I change this big load to something smaller like a 50 ohm resistor the output voltage jumped up to eight point five volts that means we need to use a voltage divider which provides a feedback voltage to control system in order to adjust the duty cycle and thus keep the output voltage steady no matter what load is attached and since this is getting a bit complicated let's keep things simple with this - 576 simple switch I see I have the 5 volt version that has it feedback resistors integrated and also only requires 4 additional parts to build up a complete buck converter the rule of thumb while recreating the schematic is to keep all the parts close together and creating fix order traces after only 10 minutes of soldering the circuit was complete works flawlessly and obviously reached a better efficiency year than my demonstration circuits and if you want to make your own power converter I can recommend the adjustable version of this IC there you can add your own feedback resistors or potentiometer to create an adjustable output voltage and with that being said you already know quite a bit about stepping down voltages efficiently with a buck converter I hope you liked it and learnt something new as well as always don't forget to Like share and subscribe consider supporting me through patreon so I can continue producing such videos stay creative and now we'll see you next timelet's say you just got a new awesome electronic module that requires five folds in order to work but all you have is a 12-volt power source the easiest solution would be to use a lm7805 voltage regulator with an input and output capacitor to step down 12 volts to 5 volts but if we measure the input and output power we can see that the efficiency is quite low and gets even worse with higher input voltages because the regulator is basically a variable resistor that converts the excess power into heats which is not recommended when the power source is a battery to reach a higher efficiency though we can use the so-called buck converter this one is very small has an adjustable output voltage doesn't cost much and also reaches a decent efficiency but how do these converters work and can we even build one by ourselves let's find it out a buck converter is a kind of SMPS or switched-mode power supply as an example I will use naught we know Nano which can switch its output pins on and off rapidly whippets pwm function here I use the value 127 which creates a square wave will be due disciple of 50% if I now measure the voltage with my multimeter it already tells me that we successfully step-down or 5 volts to 2.5 volts because it measures the average and for undemanding components like LEDs this method already does a trick but in order to control higher voltages and bigger current draws we need to upgrade the switch to a p-channel MOSFETs by hooking up 12 volts to source a 10 kilo ohm pull-up resistor between gate and source gate also to the PWM signal and going to the loads I condemn the small light bulb and by connecting a potentiometer to analog inputs and adjusting the coder pits I can also control the duty cycle and thus increase or decrease the average boot and brightness of the bulb but our switched voltage still has high voltage Peaks which will destroy sensible five-fold electronics so we have to get rid of them to do that I firstly added 100 micro Henry inductor in series to the loads this way the current cannot rise instantly because a part of the energy is stored in the electromagnetic field of the coil and once the switch opens the electromagnetic field collapses and should pump a current through the loads which it does do properly instead we get those massive voltage spikes at the switch which is not a surprise since there is no complete loop in which the current could flow and thousand electron access occurs that is why I added a Schottky diodes were below forward voltage to the circuits so that current can flow when the switch is open but the resulting current flow is still far away from a steady value to further improve that we need to increase the frequency of the PWM signal which is right now around 976 Hertz I simply change the prescaler in my sketch uploaded it and promptly got a frequency of sixty-two point five kilo Hertz with such a short off time the energy storage capacity of the inductor is now enough to smooth out the current flow quite a bit that is also the reason why switched mode power supplies usually use a high frequency in order to keep energy storage components small all that was left to do but my design was adding a 47 micro farad capacitor on the outputs to smooth out the voltage and the buck converter was complete and reach the efficiency year of 67 percent with my light bulb at 5 volts which is not terrible but once I change this big load to something smaller like a 50 ohm resistor the output voltage jumped up to eight point five volts that means we need to use a voltage divider which provides a feedback voltage to control system in order to adjust the duty cycle and thus keep the output voltage steady no matter what load is attached and since this is getting a bit complicated let's keep things simple with this - 576 simple switch I see I have the 5 volt version that has it feedback resistors integrated and also only requires 4 additional parts to build up a complete buck converter the rule of thumb while recreating the schematic is to keep all the parts close together and creating fix order traces after only 10 minutes of soldering the circuit was complete works flawlessly and obviously reached a better efficiency year than my demonstration circuits and if you want to make your own power converter I can recommend the adjustable version of this IC there you can add your own feedback resistors or potentiometer to create an adjustable output voltage and with that being said you already know quite a bit about stepping down voltages efficiently with a buck converter I hope you liked it and learnt something new as well as always don't forget to Like share and subscribe consider supporting me through patreon so I can continue producing such videos stay creative and now we'll see you next time
