Congrats, Julian! You made a power electronics circuit work on the first try! Whenever I test my stuff, it's like a bomb is about to go off. I put the circuit on a fireproof surface, with cables running to a meter or scope. And one hand is always on the power supply switch in case something goes wrong. Lots of sweat. And things do go wrong on the first try.
Yes, but this way ? A bit of math and there is proper way to do something neat. There was no output capacitor and why it needs low ESR, is accountable for buck conversion. the values need to be calculated as well. This is electronics of this age where efficiency matters. This video is for entertainment not for teaching someone.
I have run into the same issues putting brass screws into wood. It helps to screw a steel screw of the same size and pitch first and then screw the brass screw. It results in less breakage of the brass screws.
You can also place the switch component on the supply negative, rather than positive. It's not the textbook manner, but it works equally well and sometimes can simplify the MOSFET drive or allow you to use an N-type MOSFET (lower on resistance, higher current capacity) rather than P-type.
A true engineer would discard the faulty wooden block, replace it with a new one, varnish it, (3 coats at least) and write a 2 page report on the reason why.
That bit you mentioned about the diode in the MOSFET made me realize something. When I started using MOSFETs I accidentally connected positive to the source and grounded the drain, to my confusion current would flow and it would slow down very slightly when I applied voltage to the gate, but not by very much. I always wondered why this was so if the n channel seems like it should work the same way either way around. This explains it.
Why? The lamp is a pure resistor and the inductor functions as a storage element. So the L and R(lamp) function like a low-pass filter. If you leave out the inductor the voltage is not filtered, but you would get the same result. However, the voltage over the Lamp would be much higher during the Ton period time. You would see the same effect the Lamp burning less bright, but the lamp would have much more stress. This is effect would be caused by the fact that the effect of the lamp in this case is very slow (filtering the optical/thermal domain). The filtering ensures that the voltage over the Lamp is, more or less constant. It can be improved by adding a capacitor, but this is not necessary. Notice that this configuration is used in almost all TIG/MIG weld inverters.
I myself thought the inductor was so out of spec that the efficiency would be so low, almost 0, that it would be running as a PWN circuit. Maybe it's just really low but not zero so it can be a functioning buck a little.
Why? At 40 kHz a inductor around about 100 to 200 uH can already have sufficient storage energy. It depends on the current flowing in the inductor and the value of the inductor also the saturation current needs to be high enough. When I look at the size my guess is that it is around 100 a 200uH. But I have to admit we do not know the exact switching frequency. However, when Fc
Michael Shreeve I remember when you explained and referenced to Wikipedia I believe in Muppet one. While working with the Muppet 1 version which you were experimenting with the output waveform, you mentioned in one of the videos or comments that you would like to experiment with toroidal coils and efficiency and other factors. Hopefully you do that in a sort of buck series ? I know its frustrating and complex, but somebody needs to do it lol
With a constant load, a constant supply voltage and a constant duty cycle, the output voltage should in theory be constant. Whether the circuit is behaving like a buck converter or not, it all depends on the inductance, the duty cycle and the supply voltage assuming the MOSFET is switching efficiently. Omission Correction: A stable switching frequency is also important.
Love your channel, Julian, always glad to see a new video. I would note, however that this video actually doesn't show "bucking". If you remove the inductor, you would expect the circuit that you built would operate the same way: the MOSFET simply acts to pulse width modulate the current through the load. You setup might be showing some buck action, but it also might not. If you hook a scope to measure the voltage across the load, you might see the difference. You could also measure both the voltage and current across the load, and compare it to the voltage/current from the power source, and measure the efficiency.
There's an even easier way: 50% duty cycle, then short the coil. If it is indeed acting as a buck converter then the bulb will dim, but if it is only acting as a PWM driver the bulb brightness will be unchanged.
At 50% Uout = Ton/Tperiod *Uin = 0.5*Uin = 6 Volt for Buck. At 50% duty cycle the average is also 6 volt. How can I see the difference in this case? However, the difference is as buck it is filtered L and R(Lamp) so close to 6 volt and a ripple(depends on the coil). And as PWM it is 12 volt 0 volt 12 volt 0 volt etc. I don't think the intensity of the Lamp would change. The lamp is slow the at 10 kHz there is no difference. However, the lamp has more stress, because of a lack of filtering(L).
A double mention! Thank you. I do like the use of bulbs for demonstration purposes but as you'd created a buck converter it would have been nice to see a dvm (or analog volt meter) on the output. Great video though - Wikipedia image to working device. Great concept.
It's interesting and very nice way to build the miniature buck converter without output capacitor. The pace at which the design is running it seems the muppet will get his life after 10 years
Greetings all, just wanted to interrupt and ask a small favor. TH-cam has changed their grading scale again and it is more important now than ever before to take a split second to press the "like" button for all your favorite channels. It is just one small way we can say thank you to these content providers for sharing their vast knowledge with us for free! I have seen many several of my favorite channels just stop uploading content or insert ads every 30 secs and all we have to do to prevent that, is simply say thanks by pressing "like." Please and thank you.
Not sure how you can assume that it's the output voltage that's changing rather than the changes to the FET's duty cycle which is allowing more current to flow. I think maybe that circuit would still work without the diode and inductor.
Looking like I'm late to the party as I wanted to impress you all with my expertise in electronic. [crap] As others have said I don't think this is working as a buck converter. If you shorted out the inductor I bet it would control the lamp just the same. I accuse you sir of pulling the wool over our eyes with a PWM lamp dimmer. However great effort I may have to steal your idea and do this on my channel. I think you should close the loop and use feedback to regulate the output using your micro. Still a great idea for a video thanks for sharing its alway fun I love your contents and have learned a lot watching you. My best regards Chris.
Maxx B it's far more likely, given that Julian didn't actually drill all the way through the wood for every hole (not seen in the video anyway) the screw probably bottomed and the excess torque needed to try to drive the screw THROUGH wood rather than into a hole caused the shearing. All the other points raised are still valid though. However, my experience with soap on screws has been that whilst it's great to help get the screw into the wood, soap, being hygroscopic, causes steel screws to rust far more quickly. Better to scrape the thread onto a candle. Works better as it helps seal the screw against moisture and as the screw heats during driving it helps soften or even melt the wax on its way.
This is manly to the people who have given bad reviews.... SHAME ON YOU ALL. There is nothing wrong with the way this video was made, or the products that were used, or even how simple it was made. Just seeing how a Mos-Fet was used and controlled is more interesting sometimes, then the final product. You can take the ideas, and improve it yourself. If you people know so much better, why don't you have your own TH-cam videos? That's enough of that. Julian.. Keep up the good work. That's why I watch!!!!!
Always tin your iron tip with solder to prevent oxidation. Oxidation impedes thermal transfer from the tip to the joint. Wedge tips are better for general use because there's more surface contact with the joint. More surface contact means more thermal transfer.
But this is also working as plain PWM with a bridged coil. Proove the DC to DC downconverting by setting the input to e.g. 24V and scope the ouput at 50% PWM might show a rectangular signal at the bulb if the coil is to little in inductivity. An hugh cap mounted parallel to the bulb and we have a LPF with a low enough corner frequency ther will be a stable 12V.
So what are the limits like of you wanted something big like 20+ amps obviously wire gauge and a mosfet that is big enough and heat sink but would you need a real big inductor
It would be a buck converter if it had a smoothing cap at the output. I see a lot of people say this is not a buck converter because it doesn't have feedback. Wrong. Prove them wrong by putting a scope on the output (With a 470uF ~1000uF Elec. cap). Rule of thumb is 470uF for every Amp. You can quickly judge a buck or boost converter's quality, by the input and output capacitors and filtering. The bigger, the better. Size does matter :)
I just made LT spice simulation and the output voltage in the lamp without capacitor is a triangle shape pulse coming from the inductor varying around the desired output voltage.Is buck converter AND is totally different from straight PWM if inductor had replaced with a jumper because then voltage output would be square shape pulses between 0v and vcc volt.
So, to build a buck converter, you need a round thingy, a triangle thingy, a rectangular thingy, a squiggly thingy, and a door hinge. That will convert your bucks into any other currency. Got it.
It would be nice to see the duty cycle/frequency on the oscilloscope and the final output voltage to the bulb in comparative ratios if you wanted to do a follow up video...and would higher speed rectifier have a impact on the circuit?
Well just do the diffferential equations, transform it and done :D And since you are already at it you can design a matching PID-controler as well :) But tbh I think that this is neither the right channel nor the right person to expain that. I like julians videos but its clear that he is not that good with electronics so a theory lesson from him would probably interesting but i wouldnt belive a thing :) Anyways. Just google it and the first pdf is already quite nice
Hi Julian, Love your videos, but on this one I do have to agree with most of the previous comments: There is no "bucking" showed; if you remove the "buck part", you would get the same output response from the lamp (an oscilloscope and or multi-meter on the output were needed). Anyway, thanks for the great content.
People who think this is the same as PWM are mistaken. In this case it may seem like they are the same because he is dimming a light with an average voltage given by a certain duty cycle. But a buck converter gives you continuous current. So if you take the bulb out and try to power a microcontroller it would be fine (given that clean up the ripple current) but if you try to power a microcontroller with PWM your microcontroller will just turn on and off with every pwm pulse..the key is CONTINUOUS CURRENT. A pwm only gives you current durring the on time. and zero current during the off time.
Good demo but is missing reading Voltage at lamp end to see if there is "any" conversion from 12v, instead of showing PWM effect. Also, if you choose a "raw style" in your demo components, the switching oscillator choosen (arduino mini etc) is overwhelming. I would rather use an encoder pot attached to a wheel to really show same simple style in the fast switch signal generator...
Right now it is more of a dimmer than a buck converter. Add the capacitor to the output, and it will become one :) BTW, for a buck converter you can use quite a high value inductor, the more inductance the smaller ripple current will be. Disadvantage of a huge value inductor is large DC resistance which cause power loss, but you can happily whack a 1mH choke there, just make sure it can handle the current ;)
yea let's build a buck converter!!! very in to this subject. I have missed a lot of videos lately. did or are you building a boost converter? I know you think I'm crazy . for wanting to build a DC to ac spwm / pure sine wave inverter. while being self taught at that. if I can't do it . it is partly your fault. because you didn't teach me enough!! but I have learned lots from you guys.( Clive, Adam W. and you and a few others) but for the output driver section. I found the EGS002 driver board with get drivers. fan controller. and a few other features. some cone with a small display. however if I'm gonna do it . I wanna go big. like 10kw and 48v. to 120v . I have some components to do the push pull type. a huge over 100lbs 48v battery charger transformer. don't know its output. but its got 2/0 out leads. but I'd rather go higher Hz to be more efficient. but I bought a 24v 5 kW inverter to power my offgrid home. and I have a APC 1500 ups I'm going to use somehow. it also 24v. hopefully I can pickup enough. and experiment enough to at least get a small proof of concept working! I could ask you questions all day. if you would let me. thanks great video.
I think the only thing missing on this video was to hook up a volt meter where the lamp was and another one just to check the amps since it would have shown the buck feature a bit better to the viewers :)
Well if you remove the diode and replace the inductor with a wire it'll have the same effect. You should have measured the current to prove that it's drawing less current than the bulb uses.
I scroll down and a lot of guys are saying the same thing. But it's not a PWM. It just looks like a PWM controller. The current is the key here. Though they are right that a real buck converter needs feedback.
Thanks Julian. Those cheap brass posts snap off with no warning, as too many of us have discovered. // Of course this is probably not a buck converter, and if that's the case, then you could use a bipolar transistor and a pot on the Base, to dim the lamp much more simply. I suspect an agenda here, and await developments!
Oh yes ... ANYTHING can break those nickel plated brass terminal pins, and I agree that given this was a temporary setup it wouldn't matter either way (brass/nickel doesn't rust anyway). My point was a more general one relating to use of soap as a lubricant ... On full brass screws (not brass plated) it works great AND IIRC from a cabinet maker's perspective it's far less likely to discolour the wood than melted wax. But for steel screws wax in my view is a better way to go. Bottoming a screw or bolt in a blind hole, even if it's only wood, is the easiest way to shear it or strip threads or both though.
Cool. Crap, does this mean I should donate to your patreon now? I've watched pretty much all of your videos for free :-). Thanks for the videos I enjoy them very much. Cheers from Canada.
Short answer NO. The L and R are a low-pass filter lowering the voltage. The voltage then becomes. Uout = Ton/Tperiod *Uin. I am really amazed how many people do not have a clue about what they are speaking and saying this is shit and wrong and so on.
cauchy8888 The capacitor will improve the ripple quite a lot, but is not necessary. The L and R are already a low-pass filter thereby removing a part of the ripple. The C will make the LR filter into an LCR filter which is second order and will have better filtering performance.
if they think this is the same as PWM they should trying powering on a microcontroller with pwm haha, the difference is that buck converter provides average voltage AND CONTINUOUS CURRENT!
As a tutorial this is not very good. A lot has to be taken on faith. Not least that the output voltage is actually changing. (yes i can see the lamp is varying in in brightness, but it would do that with the pwm too.)
Im sure you would lol but I spent them on ebay instead I bought some variable resistors and a new arduino and some opto isolator chips so I can make julians decoy thing. but I might try to make my buck converter with a 555 chip as well i think it will work
Congrats, Julian! You made a power electronics circuit work on the first try!
Whenever I test my stuff, it's like a bomb is about to go off. I put the circuit on a fireproof surface, with cables running to a meter or scope. And one hand is always on the power supply switch in case something goes wrong. Lots of sweat.
And things do go wrong on the first try.
Thanks to this video, half of the beginner electronics hobbyists think a buck-converter involves a piece of wood, a drill, an arduino nano, ...
No idea what you're doing here and yet I still enjoy watching it. :-)
It's the TH-cam syndrome.
Wow. I am amazed this appeared to work the first time!!!! Great job as always Mr Llett!!
Very cool and simple project, it should be teached on schools.
Thanks Julian!
andresj5512 please do not underestimate kids in schools. They have grown up now.
hahaha, what? I don't mean it like that, it's a very cool project to be shown on a class room along with Ohm's law.
Yes, but this way ? A bit of math and there is proper way to do something neat. There was no output capacitor and why it needs low ESR, is accountable for buck conversion. the values need to be calculated as well. This is electronics of this age where efficiency matters. This video is for entertainment not for teaching someone.
Yeh - teached (sic) it on schools, Beavis, (barf) andresj5512, you dork, huh.... huh .. is that your IQ Andy? !!?!.
I have run into the same issues putting brass screws into wood. It helps to screw a steel screw of the same size and pitch first and then screw the brass screw. It results in less breakage of the brass screws.
You can also place the switch component on the supply negative, rather than positive. It's not the textbook manner, but it works equally well and sometimes can simplify the MOSFET drive or allow you to use an N-type MOSFET (lower on resistance, higher current capacity) rather than P-type.
A true engineer would discard the faulty wooden block, replace it with a new one, varnish it, (3 coats at least) and write a 2 page report on the reason why.
No, a true engineer is not fond of paperwork... :-)
That bit you mentioned about the diode in the MOSFET made me realize something. When I started using MOSFETs I accidentally connected positive to the source and grounded the drain, to my confusion current would flow and it would slow down very slightly when I applied voltage to the gate, but not by very much. I always wondered why this was so if the n channel seems like it should work the same way either way around. This explains it.
I suspect, as others, that a scope would prove there is no bucking going on presently, just amplified PWM.
Lawrence L exactly. I was gonna say the same thing. I'm sure he could take out the inductor and the diode and it would work just the same.
If there was no coil, I would agree with you. As it is, I do not agree with you.
Why? The lamp is a pure resistor and the inductor functions as a storage element. So the L and R(lamp) function like a low-pass filter. If you leave out the inductor the voltage is not filtered, but you would get the same result. However, the voltage over the Lamp would be much higher during the Ton period time. You would see the same effect the Lamp burning less bright, but the lamp would have much more stress. This is effect would be caused by the fact that the effect of the lamp in this case is very slow (filtering the optical/thermal domain). The filtering ensures that the voltage over the Lamp is, more or less constant. It can be improved by adding a capacitor, but this is not necessary. Notice that this configuration is used in almost all TIG/MIG weld inverters.
I myself thought the inductor was so out of spec that the efficiency would be so low, almost 0, that it would be running as a PWN circuit. Maybe it's just really low but not zero so it can be a functioning buck a little.
Why? At 40 kHz a inductor around about 100 to 200 uH can already have sufficient storage energy. It depends on the current flowing in the inductor and the value of the inductor also the saturation current needs to be high enough. When I look at the size my guess is that it is around 100 a 200uH. But I have to admit we do not know the exact switching frequency. However, when Fc
Michael Shreeve
I remember when you explained and referenced to Wikipedia I believe in Muppet one. While working with the Muppet 1 version which you were experimenting with the output waveform, you mentioned in one of the videos or comments that you would like to experiment with toroidal coils and efficiency and other factors. Hopefully you do that in a sort of buck series ? I know its frustrating and complex, but somebody needs to do it lol
With a constant load, a constant supply voltage and a constant duty cycle, the output voltage should in theory be constant. Whether the circuit is behaving like a buck converter or not, it all depends on the inductance, the duty cycle and the supply voltage assuming the MOSFET is switching efficiently.
Omission Correction:
A stable switching frequency is also important.
I like, how you can make basic simple and trivial things interesting(even after I designed dozen of convertors). I like your woodboard style!
Marek Coufal same
he obv once had the ladybird book 'making a transistor radio'
Yeah, it is really nice. Even if you now how this stuff works and design it for a living.
It would even run without the diode and coil, like a electronic speed controller, since there is 12V on the input and a 12V car lamp on the output.
Love your channel, Julian, always glad to see a new video. I would note, however that this video actually doesn't show "bucking". If you remove the inductor, you would expect the circuit that you built would operate the same way: the MOSFET simply acts to pulse width modulate the current through the load. You setup might be showing some buck action, but it also might not. If you hook a scope to measure the voltage across the load, you might see the difference. You could also measure both the voltage and current across the load, and compare it to the voltage/current from the power source, and measure the efficiency.
There's an even easier way: 50% duty cycle, then short the coil. If it is indeed acting as a buck converter then the bulb will dim, but if it is only acting as a PWM driver the bulb brightness will be unchanged.
At 50% Uout = Ton/Tperiod *Uin = 0.5*Uin = 6 Volt for Buck. At 50% duty cycle the average is also 6 volt. How can I see the difference in this case? However, the difference is as buck it is filtered L and R(Lamp) so close to 6 volt and a ripple(depends on the coil). And as PWM it is 12 volt 0 volt 12 volt 0 volt etc. I don't think the intensity of the Lamp would change. The lamp is slow the at 10 kHz there is no difference. However, the lamp has more stress, because of a lack of filtering(L).
A double mention! Thank you. I do like the use of bulbs for demonstration purposes but as you'd created a buck converter it would have been nice to see a dvm (or analog volt meter) on the output. Great video though - Wikipedia image to working device. Great concept.
If it is a buck converter then without a smoothing cap a DVM would read all over the place.
It's interesting and very nice way to build the miniature buck converter without output capacitor. The pace at which the design is running it seems the muppet will get his life after 10 years
Greetings all, just wanted to interrupt and ask a small favor. TH-cam has changed their grading scale again and it is more important now than ever before to take a split second to press the "like" button for all your favorite channels. It is just one small way we can say thank you to these content providers for sharing their vast knowledge with us for free! I have seen many several of my favorite channels just stop uploading content or insert ads every 30 secs and all we have to do to prevent that, is simply say thanks by pressing "like." Please and thank you.
How about also doing a boost circuit - leading on to a diy sepic converter?
Not sure how you can assume that it's the output voltage that's changing rather than the changes to the FET's duty cycle which is allowing more current to flow. I think maybe that circuit would still work without the diode and inductor.
Looking like I'm late to the party as I wanted to impress you all with my expertise in electronic. [crap] As others have said I don't think this is working as a buck converter. If you shorted out the inductor I bet it would control the lamp just the same. I accuse you sir of pulling the wool over our eyes with a PWM lamp dimmer. However great effort I may have to steal your idea and do this on my channel. I think you should close the loop and use feedback to regulate the output using your micro. Still a great idea for a video thanks for sharing its alway fun I love your contents and have learned a lot watching you. My best regards Chris.
Julian use soap when you try to screw anything in wood it works like lubricant but it is dry!
Doing anything with hard wood, always goes better with lubricant.
Maxx B it's far more likely, given that Julian didn't actually drill all the way through the wood for every hole (not seen in the video anyway) the screw probably bottomed and the excess torque needed to try to drive the screw THROUGH wood rather than into a hole caused the shearing. All the other points raised are still valid though.
However, my experience with soap on screws has been that whilst it's great to help get the screw into the wood, soap, being hygroscopic, causes steel screws to rust far more quickly. Better to scrape the thread onto a candle. Works better as it helps seal the screw against moisture and as the screw heats during driving it helps soften or even melt the wax on its way.
I don't think that this wil be permanent setup and the screws are probably nickel plated but for a permanent setup you are right.
This is manly to the people who have given bad reviews.... SHAME ON YOU ALL. There is nothing wrong with the way this video was made, or the products that were used, or even how simple it was made. Just seeing how a Mos-Fet was used and controlled is more interesting sometimes, then the final product. You can take the ideas, and improve it yourself.
If you people know so much better, why don't you have your own TH-cam videos?
That's enough of that.
Julian.. Keep up the good work.
That's why I watch!!!!!
Take ideas and improve what,the buck mode converter?
I'm talking about the many uses for the Mos-fet's. If you cant learn then why watch, just to complain????
Always tin your iron tip with solder to prevent oxidation. Oxidation impedes thermal transfer from the tip to the joint. Wedge tips are better for general use because there's more surface contact with the joint. More surface contact means more thermal transfer.
would be nice to see a scope of the output and any additional components used to clean the output up
I am your fan. I bought ming hi 3806 module inspired by ur channel
What is the output voltage? To keep it simple, couldn't the Arduino be replaced with a 555 astable multi-vibrator.
But this is also working as plain PWM with a bridged coil. Proove the DC to DC downconverting by setting the input to e.g. 24V and scope the ouput at 50% PWM might show a rectangular signal at the bulb if the coil is to little in inductivity. An hugh cap mounted parallel to the bulb and we have a LPF with a low enough corner frequency ther will be a stable 12V.
So what are the limits like of you wanted something big like 20+ amps obviously wire gauge and a mosfet that is big enough and heat sink but would you need a real big inductor
It would be a buck converter if it had a smoothing cap at the output. I see a lot of people say this is not a buck converter because it doesn't have feedback. Wrong.
Prove them wrong by putting a scope on the output (With a 470uF ~1000uF Elec. cap). Rule of thumb is 470uF for every Amp.
You can quickly judge a buck or boost converter's quality, by the input and output capacitors and filtering. The bigger, the better.
Size does matter :)
I just made LT spice simulation and the output voltage in the lamp without capacitor is a triangle shape pulse coming from the inductor varying around the desired output voltage.Is buck converter AND is totally different from straight PWM if inductor had replaced with a jumper because then voltage output would be square shape pulses between 0v and vcc volt.
I like your build-it style videos, thanks :) great watch
Very sly the way you substituted that mechanical switch with a mosfet at the last minute! Great video.
So, to build a buck converter, you need a round thingy, a triangle thingy, a rectangular thingy, a squiggly thingy, and a door hinge. That will convert your bucks into any other currency. Got it.
It would be nice to see the duty cycle/frequency on the oscilloscope and the final output voltage to the bulb in comparative ratios if you wanted to do a follow up video...and would higher speed rectifier have a impact on the circuit?
this is still a better kit than those from the one pound shops
I am confused please. How are you driving the MOSFET through the gate and source. I thought it is only the gate that should receive the pwm signal.
How about the control theory over buck converter? Transfer function and sort?
Well just do the diffferential equations, transform it and done :D And since you are already at it you can design a matching PID-controler as well :)
But tbh I think that this is neither the right channel nor the right person to expain that. I like julians videos but its clear that he is not that good with electronics so a theory lesson from him would probably interesting but i wouldnt belive a thing :)
Anyways. Just google it and the first pdf is already quite nice
how about also offsetting the negative input to enable ocd trigger-free operation? ;-)
Hi Julian, Love your videos, but on this one I do have to agree with most of the previous comments: There is no "bucking" showed; if you remove the "buck part", you would get the same output response from the lamp (an oscilloscope and or multi-meter on the output were needed). Anyway, thanks for the great content.
Hello julian
Its realy an intersting tiny project
But what is the power efficiency of the circuit
Hope you ll answer me
the way you explain it is amazing! btw what happen to the switch you shown earlier?
People who think this is the same as PWM are mistaken. In this case it may seem like they are the same because he is dimming a light with an average voltage given by a certain duty cycle. But a buck converter gives you continuous current. So if you take the bulb out and try to power a microcontroller it would be fine (given that clean up the ripple current) but if you try to power a microcontroller with PWM your microcontroller will just turn on and off with every pwm pulse..the key is CONTINUOUS CURRENT. A pwm only gives you current durring the on time. and zero current during the off time.
Good demo but is missing reading Voltage at lamp end to see if there is "any" conversion from 12v, instead of showing PWM effect. Also, if you choose a "raw style" in your demo components, the switching oscillator choosen (arduino mini etc) is overwhelming. I would rather use an encoder pot attached to a wheel to really show same simple style in the fast switch signal generator...
Hi Julian - Your breadboard looks like a piece of slat from a bed... Shouldn't it be a bedboard instead?
how to know the pulse gate in mosfet?
can you also do boost converter? and later on may be buck boost.
Right now it is more of a dimmer than a buck converter. Add the capacitor to the output, and it will become one :) BTW, for a buck converter you can use quite a high value inductor, the more inductance the smaller ripple current will be. Disadvantage of a huge value inductor is large DC resistance which cause power loss, but you can happily whack a 1mH choke there, just make sure it can handle the current ;)
simply brilliant, thanks Julien
yea let's build a buck converter!!! very in to this subject. I have missed a lot of videos lately. did or are you building a boost converter? I know you think I'm crazy . for wanting to build a DC to ac spwm / pure sine wave inverter. while being self taught at that. if I can't do it . it is partly your fault. because you didn't teach me enough!! but I have learned lots from you guys.( Clive, Adam W. and you and a few others) but for the output driver section. I found the EGS002 driver board with get drivers. fan controller. and a few other features. some cone with a small display. however if I'm gonna do it . I wanna go big. like 10kw and 48v. to 120v . I have some components to do the push pull type. a huge over 100lbs 48v battery charger transformer. don't know its output. but its got 2/0 out leads. but I'd rather go higher Hz to be more efficient. but I bought a 24v 5 kW inverter to power my offgrid home. and I have a APC 1500 ups I'm going to use somehow. it also 24v. hopefully I can pickup enough. and experiment enough to at least get a small proof of concept working! I could ask you questions all day. if you would let me. thanks great video.
I think the only thing missing on this video was to hook up a volt meter where the lamp was and another one just to check the amps since it would have shown the buck feature a bit better to the viewers :)
tbbw that will come across when he prints the next page of Wikipedia
Thank much!
Would like to see more with regulated output.
Khun. Roma is going to implement PID control loop so stay tuned
waiting for part 2 where you explain how to pick the right size of inductor, that'll be more interesting, same thing for boost
Well if you remove the diode and replace the inductor with a wire it'll have the same effect. You should have measured the current to prove that it's drawing less current than the bulb uses.
I scroll down and a lot of guys are saying the same thing. But it's not a PWM. It just looks like a PWM controller. The current is the key here. Though they are right that a real buck converter needs feedback.
That's a great little circuit, just the sort of thing I need for my LED light project that I am failing to get right.
RPS Project for controlling LED you don't need an inductor. Just pwm the supply voltage and it will automatically control the brightness
That was good. Build a mechanical circuit. Variable speed motor with a cam to activate the mechanical switch.
So, if you swap out the diode with a cap, you can make a boost converter?
I have been looking for something like the connectors you used (and broke). Did I miss their mail bag? Any hints for search terms to find them?
Thanks Julian. Those cheap brass posts snap off with no warning, as too many of us have discovered. // Of course this is probably not a buck converter, and if that's the case, then you could use a bipolar transistor and a pot on the Base, to dim the lamp much more simply. I suspect an agenda here, and await developments!
Not so much an agenda as a first step. The next step is to check for current gain :)
Oh yes ... ANYTHING can break those nickel plated brass terminal pins, and I agree that given this was a temporary setup it wouldn't matter either way (brass/nickel doesn't rust anyway). My point was a more general one relating to use of soap as a lubricant ... On full brass screws (not brass plated) it works great AND IIRC from a cabinet maker's perspective it's far less likely to discolour the wood than melted wax. But for steel screws wax in my view is a better way to go.
Bottoming a screw or bolt in a blind hole, even if it's only wood, is the easiest way to shear it or strip threads or both though.
Dont you use that sponge you know dont you clean the tip after every use ?
What happens if you replace the inductor with a short circuit.?
I think it would just act as a regular switch then since no emf field would be stored.
Is that wood left over from your shed build?
how have you control losses and switching frequency? please do reply
sounds like the drill running in reverse
That PWM circuit is massive overkill. Use a 555 instead
Where did you get that compact power supply?
Good explanation!
dude ,, isnt there supposed to be a capacitor in parrallel with the load?
i guess that is for AC
why not scope the output to see things like ripple? Then learn about low-pass filters :-)
Next video: Let's scope the buck converter :)
Cool. Crap, does this mean I should donate to your patreon now? I've watched pretty much all of your videos for free :-). Thanks for the videos I enjoy them very much. Cheers from Canada.
Good idea. So far, it just looks like PWM ;-)
+Jay Herde True. To test that, I'll be looking for current gain.
Maybe I'm missing something but in this design it seems like P channel mosfet is the right thing as Vg must be greater then Vs.
Kept thinking, if he keeps building and improving designs like these we might mistake you for Victor... clue... Mary Shelley (author)
"A monument to my mechanical ineptitude" :)
Thanks for sharing. Good scope :-)
I did also announced my wishlist to Adam, the earlier, the shorter ;-)
You didn't measure the output voltage?!
What's that DC to DC converter you use all the time? I want it for my own project! :)
Somebody buy that man a vice !!
"Let's Build a Buck Converter" : good idea. Another idea : building a buck converter from linear technology (commenting the datasheet).
I once built a buck converter from a shovel, some plastic bags, a machete and some other parts I have lying around in the the trunk of my car.
@@SirArghPirate That would be a Buck composter :)
@@davidc.3145 lol
what is that drill i need it in my life
Joshua Hutton go for makita tools
I always feel alarmed seeing people drilling holes into something they are just holding in their other hand. I would never do that,
Dude, youd have the same effect just with the pwm signal 😂
cauchy8888 when you are just using a resistive load, pwm has the same effect as buck, in norma circumstances like this
Short answer NO. The L and R are a low-pass filter lowering the voltage. The voltage then becomes. Uout = Ton/Tperiod *Uin. I am really amazed how many people do not have a clue about what they are speaking and saying this is shit and wrong and so on.
cauchy8888 The capacitor will improve the ripple quite a lot, but is not necessary. The L and R are already a low-pass filter thereby removing a part of the ripple. The C will make the LR filter into an LCR filter which is second order and will have better filtering performance.
if they think this is the same as PWM they should trying powering on a microcontroller with pwm haha, the difference is that buck converter provides average voltage AND CONTINUOUS CURRENT!
step 1 out of 5 for building your evil machine
Waas wid de wooden breadboard Jules? We goin' Retro?
Dimmer?
Charles D Parker now it's buck converter
As a tutorial this is not very good. A lot has to be taken on faith. Not least that the output voltage is actually changing.
(yes i can see the lamp is varying in in brightness, but it would do that with the pwm too.)
Offset post? That just means it's pin 1!
Just imagine if everyone who's checked out this video donated a buck (or a pound) or equivalent, , a month. Patreon.
Thank you
RIGHT!!
This is more on breadboard than usual
I want to build a buck converter too
Im sure you would lol but I spent them on ebay instead I bought some variable resistors and a new arduino and some opto isolator chips so I can make julians decoy thing. but I might try to make my buck converter with a 555 chip as well i think it will work
You need some sharper drill bits haha!
Build an analog volt reader
Let's Build a Buck Converter easy
2:34 deeze nuts XD
No evidence here about buck converting. You feed 12V lamp from 12V source.
You dont even need the coil and diode :-)
You should have just used a punch and knocked out that one
a wooden breadboard this time 😁
Yes.
No.
Maybe.
Yes it's definitely yes. Well maybe.