Thanks CameramanLink The Choke does a great job, and if you added a voltage regulator you would have the next best thing to a battery. I hope these last two videos help the people who are getting started in electronics. Power supplies are a good starting point.
I also recommend finding previously designed power supplies that will perform the work needed. This can save you a lot of time and sometimes you find a new idea you hadn't thought about.
Outstanding as usual. Thanks for the time and effort you put into all of your videos. Your passion for teaching and sharing your knowledge is very much appreciated.
Rick, In terms of instruction, it just doesn't get any better than this vid. It answered all my lingering PI filter questions. Clear as a bell. Super job, my friend. I know it took a lot of work to put it together, and very much appreciate your efforts. Thanks again for another fine vid.. Regards, John
@3mustardMoNkEyS There are a number of PI filter calculators on the web now. Basically it is an RC or LC time constant, so the frequency of what you want to filter out is important. For a full wave power supply the frequency would be 30 Hz. For a half wave 60Hz.
Thanks sparkey1958 A good way of getting that information is to look at the diagrams of other power supplies with chokes. Because the engineering has been done. I would try a choke first before increasing the cap MFD.
Thanks Alex1M6 It can, but the choke is designed to carry the current for the load. Thats the engineering part. Choose a choke to small and it will over heat. But you do not want to over do it either, you could choose one way to big and it will work just fine, but cost a lot. So you want one that will do the job for minimum cost.
@78recordrepair The Scope was on AC to keep the top of the DC level on the screen, but when I disconnect the DC there is a no signal trace across the screen. The connect and disconnect form a circuit moves the trace in opposite directions, but both return to the center of the screen. The circuit is always pictured when there is a DC signal form that circuit.
Very nice presentation Capacitor is an electronic energy reservoir and inductor is an magnetic energy reservoir , the two reservoirs combined can smooth the energy flow
Thanks joernone Thanks John, When someone starts into learning electronic circuits, everything looks different, and it is not. The information in the last two video can be used and is used in may circuits, not just power supplies. Of course the values of the parts and the configuration, determines the behavior of the circuit, but it is really the same stuff. Ones you understand the basics. Regards, Rick
Thanks zigmaex Chokes really do a great job of filtering. But comparing the cost of a choke to a resistor, the choke cost more. Also chokes are heavier than resistors and usually bigger too. So cost, and physical requirements may determine that a resistor is used over a choke.
Thanks ntjbjhq Neat question. Yes the ripple would be more with just a straight wire and with the 47uF+33uF=80uF filter capacitors. And Yes the 500 resistor does help in smoothing the ripple. It is called an RC Time Constant. The choice of the values, of the capacitors and resistor are chosen, so that they charge and discharge at the right Time Constant to smooth out the DC.
Awesome...as always. I would be interested in being able to apply a PI formula for determining the values of the components. I suppose it's out there but you have an extraordinary talent for simplifying instruction so that almost anyone (including me) can understand it. It is a great gift and I am so glad you are sharing it. Thanks!
très bonne représentation j espert une vidéo comme celui la sur le ROS et leSWR .j aime beaucoup la radio d émission et réception et merci encore une fois sur votre aide
The first step would be to determine your specifications for the work your power supply needs to deliver. The next step would be to use a pi filter calculator to determine the size and type.
Hi Rick I’am obliged to you many thanks for replying your a Gentleman I had already watched the video you recommended I was not sure about voltages because the tapping on the transformer is 220vac I am getting 6.3vac at 200vac on variac I assumed I would get 6.3vac at the 220 which was the original voltage of the radio. Uk is 240vac that is why I have to drop approx 40vac to keep the filament voltage at 6.3vac. I think this is what you recommended in the video regarding Selenium rectifier replacement, hope this makes sense. Thanks for your knowledge and understanding, go safe.
Thank you for the video, as chokes can be hard to get, are you able to school us on how to build them for all types of supplies? Is there are calculator out there or a formula for calculating the correct uH for say a 6.3v heater supply and a 250v rail supply? Thanks!
I think these links are useful. resources.pcb.cadence.com/blog/2020-passive-pi-filter-design-and-simulation www.digikey.com/en/resources/conversion-calculators/conversion-calculator-low-pass-and-high-pass-filter www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm
Thank you. This helps me understand how the choke (really?) works. In fact, I think you have the best real life tutorial regarding this part of the power supply. What was the purpose of adding the 167 ohm load resistor to this circuit? I think I missed something there. So much appreciate your work.
Great videos. They help me a lot as I'm not an expert, but a collector and restorer of old radios. May I suggest a video about "How to use oscilloscope on old radios troubleshooting"? Thanks, Kadulazarini, Cape Old Radio
Excellent video. very clear and easy for a beginner like me to understand. One question though, does the choke get hot/warm from filtering out all of that ripple current?
Brilliant Rick, I have an AEG super5 tube radio 1951 my problem is it has 220vac transformer. I am in UK 244vac is normal where I live. If I set filament voltages to 6.3vac my variac reads 200vac I have to drop approx 40v on incoming supply to keep filaments happy. My output tube EL41 plate is 258vdc should be 245vdc. Can I reduce ac voltage before transformer and then after rectifier. By the way rectifier was Selenium I have replaced with single 1n4007 diode. Would it be beneficial to have full wave rectifier. Hope you are keeping well Rick it’s a pleasure to watch your videos, go safe. Watching this video I thought about possibly using a choke as you say it offers more resistance/reactance to reduce ac supply is this possible?
Yes it is possible to drop the voltage using a resistor or a choke at the AC power input. You should be successful using a VARIAC, so you do not damage your radio. The replacement of the selenium rectifier with the diode is common, I have done this several times. There is one more thing to consider when replacing selenium rectifiers, and that is the internal resistance of the selenium rectifier. It's been my experience that this internal resistance is usually 150 to 200 ohms, so what is needed is a resistor of about 150 ohms in series with the replacement diode. This should bring your plate voltage back to where it should be. I did do a video on this and below is the link. Replacing Selenium Rectifiers in Tube Portable Radios czcams.com/video/ZLgUFG3zmfc/video.html
@dpjb2930 Jp I don't know what the Henrys are I just garbed a coil on the workbench. There's many PI filter calculators on line and this is one. coil32.net/online-calculators/pi-matching-network-calculator.html
Thank you, and your welcome. Here are some sites to explore. resources.pcb.cadence.com/blog/2020-passive-pi-filter-design-and-simulation www.rfwireless-world.com/calculators/Pi-LC-Low-Pass-Filter-calculator.html
Interesting video as always, thanks! One question, what would the ripploe look like if you eliminated both the coil and the resistor and did a straight jump across with just the 2 filter caps in place? Would the ripple be worse than even the resistor? I'm sure the choke made it smoother overall, but between the resistor and a straight jump would there be much difference or does the resistor really help anything?
Thank you so much for your content, this is very interesting and helpful - I wanted to ask you, how do you safely hook up the o-scope to the different points in the psu? I have a hameg 604 and ungrounded outlets where i work (220ac @50hz), i know it should be safe but i want to double check bc i really like my dinosaur oscilloscope and wouldn't want to burn it.
I use a isolation transformer on the test chassis so it is save to connect the oscilloscope ground to the chases. If you do not have an isolation transformer you can use 630WVAC capacitor. For the ground put .47uF @ 630WVAC in series from the oscilloscope ground to the test chassis. This will isolate the oscilloscope AC from the chassis, but let Audio through RF pass to the input to the oscilloscope. If this is not clear I'll be glad to make a drawing.
@@AllAmericanFiveRadio thank you for your help, so,, to make sure i understood correctly, 1x630v .47uF in series to ground? I want to mention that i do not have an isolation transformer and the outlets in my house(except the kitchen) aren't connected to earth(for this application it might be a good thing) but i did just ordered myself a 375w light bulb to make a current limiter. I want to use the scope to check ripple in the rectifier of my 5f1 fender champ that i build myself(i used a choke instead of a resistor so maybe 5e1), I want to mess around with different part values to get the cleanest dc power. The probes should be in x10 attenuation position, i assume, for that type o measurements?
Hey, thanks for the great video, I have a question though. I have a large load (about 3 ohms) and I am building a supply for it where at maximum it would be running around 40 volts at about 15 amps, where I use a step down transformer and a bridge rectifier. I need to take very accurate current and voltage measurements on the output of the supply for the purpose of measuring efficiency, and I was wondering if I really needed to add a good filter in my supply or if I could just leave it rough.
Hi I came across your video because I have some type of filter and someone showed me a link to your video trying to describe the filter I have but you’re talking about DC in your video but the filter I have is on the AC side incoming 120 V power in series and parallel with the hot and neutral feed into a microwave oven transformer a.k.a. MOT. I build projects with MOT’s and was wondering if having that filter in the circuit for projects other than the microwave does it affect in a positive way the operation of the transformer say producing any heat generated by inefficiencies in transformer or is it just the same running the transformer with hot neutral directly from mains? I’m not sure if I can post a picture here but if you have a way I could send you a picture of the circuitboard with the filter unless you don’t need one and you understand what my filter looks like.
that help me out with a problem. but still, I can't know how to smooth a transformer 600W 30V 20A ( 15v - 0 - 15v). I use 2 diode 30amp with (2 capacitors 25V 0.5 F that have board smooth current starter ) it helps good until the current reach 10amp and they start to collapse with the signal smooth. so I must have a way to create a shock filter that can smooth 20 amp but i don't know how to make it
Thanks jfeet28 A good place to start studying formulas for PI filter circuits would be to Google: RC time constant LC time constant And the frequency for a half wave I think would be 30Hz and for a full-wave would be 60Hz. Hope this help; and thanks again.
great sir. i did the same to my scope after your video.i try to make (actually improve) an LC filter for my mig welder.i did all the measurements of the capacitor and the inductor ,but its almost impossible to find any equations to put them in. i can find equations in radio or smps but here we have full rectified ac , so its not pure dc , but its not ac either. how can we calculate anything?
Very helpful please can you tel me what coil do i need for 350V dc power suply. i heave build an Stereo amplifire with 2 x ECC83 (12ATX7) and 2 x EL84 (6BQ5)and i hear a 50hz noise in the speaker in the curent power suplay i have use two 50μf / 450v with an 1kohm resistor betwin cupasitors bat it seams not enough for filtering.
@@filippf12 If the humming varies with the volume, this means you are amplifying the humming. This may or may not originate from the power supply, you maybe picking the humming from something getting into the front end of your amplifier. If the humming does not vary when you change the volume control this means the problem is in the filtering of your power supply. There is a lot of help on the web nowadays, this is just one website to give you some ideas. PI NETWORK IMPEDANCE MATCHING www.eeweb.com/tools/pi-match
Why is one capacitor 47 & the other 33 uF? Would this also work with two 47 uF caps? I have 50 Hz here in Germany ...do I need other values? 😞 I want to build a plate supply for various tube projects with 300, 250, 170 & 90 VDC. 💥 Is it possible to wind a choke on a big"Amidon" ferite core (chokes are hard to find these days😔) ...if so how many Henry or mH do I need? Bye! 🙋
Usually the first filter cap is higher in value. Has to do with RC time constant using a resistor, or LC if you use a Choke. There is lots of PI Filter Calculators now, its great. Google PI Filter Calculator. I like this one. EEWEB www.eeweb.com/tools/pi-match
i did some simulation on multisim(my objective was to create a voltage spike on the AC circuit and to reduce it), what i did was an ac source connected to a function generator to create a voltage spike on the AC circuit and it just so happen i just experimenting components and this pi-filter actually worked to it. The voltage spike in the circuit was remove with very little distortion in it and the output is still in sine wave. can you explain to me why did it worked to the circuit?
great video....so if i am working on a amplifier with a 5U4 rectifier, and have replaced the filter caps, but still have some ripple[hum] i can increase the value of caps up to the design limits of the rectifier tube...and then add a choke to get rid of any ripple remaining? if so, what would the average value of the choke i would need?..thanks, bob
GOOGLE pi filter calculator Home of RF and Wireless Vendors and Resources www.rfwireless-world.com/calculators/Pi-LC-Low-Pass-Filter-calculator.html Low Pass/High Pass Filter Calculator www.digikey.com/en/resources/conversion-calculators/conversion-calculator-low-pass-and-high-pass-filter
Would I get your results with bigger capacitors? I need 36vdc @ 4A. No ripple. Two 4700uf filter capacitors. Is the theory the same in just increasing the amount of capacitance?
By changing the components values and configuration, you can make a power supply filters like this, or high pass filters, or low pass filters at different frequencies. Just Google High pass or Low pass filer.
Pi filters are used in all kinds of power amps, and some that are thousands of watts. The components in the power supply and filter circuit are designed to handle the rated power.
@@AllAmericanFiveRadio sir thank you soo much for your reply . I have one more question sir can i increase the value of capacitor and inductor to get good results .
@@kryptocat4240 Increasing the values usually results in better performance. There are many calculators for PI filters. You many be interested this. www.pronine.ca/butlf1.htm
+Cadet Hassan The voltage ripple is not produced by resistor , ripple is produced by rectifier from AC to DC so before our filter - our filter role is to smooth the ripple . The capacitors + resistor + inductors have the role to smooth the ripple because they act like energy reservoirs . The resistor is less efficient compared to inductor for smoothig the ripple . A combinations of 2 capacitor in series with an inductor between is named PI FILTER because geometrically it looks like the greek PI simbol
Because V = IR. Less current can flow so in turn more voltage is produced. If you want an analogy, think of a constant volume of water flowing through a pipe. If the diameter of the pipe is reduced, the pressure must go up to compensate for the resistance encountered.
Best explanation and demonstration I’ve seen on this subject. Nice job!
THANK YOU!
Thanks CameramanLink
The Choke does a great job, and if you added a voltage regulator you would have the next best thing to a battery. I hope these last two videos help the people who are getting started in electronics. Power supplies are a good starting point.
11 years and still usefull, thank you!
Thank you, and your welcome.
I also recommend finding previously designed power supplies that will perform the work needed. This can save you a lot of time and sometimes you find a new idea you hadn't thought about.
Outstanding as usual. Thanks for the time and effort you put into all of your videos. Your passion for teaching and sharing your knowledge is very much appreciated.
Thank you.
Your explanation is very clear!! Thank you!!
Thank you.
Wow! ❤The best video on CZcams in this topic! You are a very good teacher! 👌
Thank you, and your welcome.
This is great another fantastic demonstration.
Thank you, and your welcome.
Rick,
In terms of instruction, it just doesn't get any better than this vid. It answered all my lingering PI filter questions. Clear as a bell. Super job, my friend. I know it took a lot of work to put it together, and very much appreciate your efforts.
Thanks again for another fine vid..
Regards,
John
Thank you.
@3mustardMoNkEyS
There are a number of PI filter calculators on the web now. Basically it is an RC or LC time constant, so the frequency of what you want to filter out is important. For a full wave power supply the frequency would be 30 Hz. For a half wave 60Hz.
Great practical demonstration. Many thanks!
Thanks
Yes, CLC filter (Pi choke filter) for DC is the best that I prefer. Thanks for your presentation about CLC filter !
Thank you, and your welcome.
Excellent presentation !
Thanks a lot for making this video.
Thanks
Thanks sparkey1958
A good way of getting that information is to look at the diagrams of other power supplies with chokes. Because the engineering has been done. I would try a choke first before increasing the cap MFD.
Great lesson, as always! Hope to see more.
Thank you.
Thank you, best demo I have seen.
Thank you, and your welcome.
Thanks Alex1M6
It can, but the choke is designed to carry the current for the load. Thats the engineering part. Choose a choke to small and it will over heat. But you do not want to over do it either, you could choose one way to big and it will work just fine, but cost a lot. So you want one that will do the job for minimum cost.
@78recordrepair
The Scope was on AC to keep the top of the DC level on the screen, but when I disconnect the DC there is a no signal trace across the screen. The connect and disconnect form a circuit moves the trace in opposite directions, but both return to the center of the screen. The circuit is always pictured when there is a DC signal form that circuit.
Very nice presentation
Capacitor is an electronic energy reservoir and inductor is an magnetic energy reservoir , the two reservoirs combined can smooth the energy flow
+MonkeyBlueAss Thanks
Thanks joernone
Thanks John,
When someone starts into learning electronic circuits, everything looks different, and it is not. The information in the last two video can be used and is used in may circuits, not just power supplies. Of course the values of the parts and the configuration, determines the behavior of the circuit, but it is really the same stuff. Ones you understand the basics.
Regards,
Rick
Great job as usual Rick.
Thank you.
Thanks zigmaex
Chokes really do a great job of filtering. But comparing the cost of a choke to a resistor, the choke cost more. Also chokes are heavier than resistors and usually bigger too. So cost, and physical requirements may determine that a resistor is used over a choke.
Great demonstration on the Pi filter! Thanks for the video! Take Care--Larry
Thank you, and your welcome.
Thanks ntjbjhq
Neat question. Yes the ripple would be more with just a straight wire and with the 47uF+33uF=80uF filter capacitors. And Yes the 500 resistor does help in smoothing the ripple. It is called an RC Time Constant. The choice of the values, of the capacitors and resistor are chosen, so that they charge and discharge at the right Time Constant to smooth out the DC.
Awesome...as always. I would be interested in being able to apply a PI formula for determining the values of the components. I suppose it's out there but you have an extraordinary talent for simplifying instruction so that almost anyone (including me) can understand it. It is a great gift and I am so glad you are sharing it. Thanks!
Thank you.
Thank you very much this explanation in the summary and detail, save a very large experimental for me, thank you, and may God bless you
Thank you.
Great tutorial; thank you.
Thanks, and your welcome.
very good...Thanks for making this video
Your welcome.
très bonne représentation
j espert une vidéo comme celui la sur le ROS et leSWR .j aime beaucoup la radio d émission et réception
et merci encore une fois sur votre aide
THANKS
awesome explaination
Thank you, and your welcome. Hope this video helps.
I'll put it on my CZcams to do list.
now this is interesting.......and also to actually see it on a scope!
Thank you.
Excellent an concept clearing vdo.
Thanks
Thanks Albinorama
The first step would be to determine your specifications for the work your power supply needs to deliver. The next step would be to use a pi filter calculator to determine the size and type.
Hi Rick I’am obliged to you many thanks for replying your a Gentleman I had already watched the video you recommended I was not sure about voltages because the tapping on the transformer is 220vac I am getting 6.3vac at 200vac on variac I assumed I would get 6.3vac at the 220 which was the original voltage of the radio. Uk is 240vac that is why I have to drop approx 40vac to keep the filament voltage at 6.3vac. I think this is what you recommended in the video regarding Selenium rectifier replacement, hope this makes sense. Thanks for your knowledge and understanding, go safe.
Thanks.
Good video! One note - "AC Resistance" is better translated to "reactance," as opposed to "impedance." Impedance = resistance + reactance. 2:00
Practical EE
practicalee.com/impedance/
beautiful experiencie !
Thanks
keep up the good work! Thanks!
Thank you.
Thank you for the video, as chokes can be hard to get, are you able to school us on how to build them for all types of supplies? Is there are calculator out there or a formula for calculating the correct uH for say a 6.3v heater supply and a 250v rail supply? Thanks!
I think these links are useful.
resources.pcb.cadence.com/blog/2020-passive-pi-filter-design-and-simulation
www.digikey.com/en/resources/conversion-calculators/conversion-calculator-low-pass-and-high-pass-filter
www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm
Thank you. This helps me understand how the choke (really?) works. In fact, I think you have the best real life tutorial regarding this part of the power supply. What was the purpose of adding the 167 ohm load resistor to this circuit? I think I missed something there. So much appreciate your work.
This shows that in inductor works better than a resistor in a power supply. But you usually see resistors and power supplies because they are cheaper.
Thanks ossopalatino
Great videos. They help me a lot as I'm not an expert, but a collector and restorer of old radios. May I suggest a video about "How to use oscilloscope on old radios troubleshooting"?
Thanks, Kadulazarini, Cape Old Radio
Thank you.
Excellent video. very clear and easy for a beginner like me to understand.
One question though, does the choke get hot/warm from filtering out all of that ripple current?
Not in this circuit. Thank you.
Brilliant Rick, I have an AEG super5 tube radio 1951 my problem is it has 220vac transformer. I am in UK 244vac is normal where I live. If I set filament voltages to 6.3vac my variac reads 200vac I have to drop approx 40v on incoming supply to keep filaments happy. My output tube EL41 plate is 258vdc should be 245vdc. Can I reduce ac voltage before transformer and then after rectifier. By the way rectifier was Selenium I have replaced with single 1n4007 diode. Would it be beneficial to have full wave rectifier. Hope you are keeping well Rick it’s a pleasure to watch your videos, go safe. Watching this video I thought about possibly using a choke as you say it offers more resistance/reactance to reduce ac supply is this possible?
Yes it is possible to drop the voltage using a resistor or a choke at the AC power input. You should be successful using a VARIAC, so you do not damage your radio. The replacement of the selenium rectifier with the diode is common, I have done this several times. There is one more thing to consider when replacing selenium rectifiers, and that is the internal resistance of the selenium rectifier. It's been my experience that this internal resistance is usually 150 to 200 ohms, so what is needed is a resistor of about 150 ohms in series with the replacement diode. This should bring your plate voltage back to where it should be. I did do a video on this and below is the link.
Replacing Selenium Rectifiers in Tube Portable Radios
czcams.com/video/ZLgUFG3zmfc/video.html
Thanks petertsg
@jfeet28
Also Google:
pi filter calculator
pi filter design
@dpjb2930 Jp I don't know what the Henrys are I just garbed a coil on the workbench. There's many PI filter calculators on line and this is one.
coil32.net/online-calculators/pi-matching-network-calculator.html
@dpjb2930 Jp coil32.net/online-calculators/pi-matching-network-calculator.html
Nice tutorial thank you
I would like to know if there is a formula to calculate the values of the components C1, C2, and L.
Thank you very much.
Thank you, and your welcome.
Here are some sites to explore.
resources.pcb.cadence.com/blog/2020-passive-pi-filter-design-and-simulation
www.rfwireless-world.com/calculators/Pi-LC-Low-Pass-Filter-calculator.html
Thank you
Thank you.
Interesting video as always, thanks!
One question, what would the ripploe look like if you eliminated both the coil and the resistor and did a straight jump across with just the 2 filter caps in place? Would the ripple be worse than even the resistor? I'm sure the choke made it smoother overall, but between the resistor and a straight jump would there be much difference or does the resistor really help anything?
It is pulsating DC.
Thanks hunt555fish
Thank you so much for your content, this is very interesting and helpful - I wanted to ask you, how do you safely hook up the o-scope to the different points in the psu? I have a hameg 604 and ungrounded outlets where i work (220ac @50hz), i know it should be safe but i want to double check bc i really like my dinosaur oscilloscope and wouldn't want to burn it.
I use a isolation transformer on the test chassis so it is save to connect the oscilloscope ground to the chases. If you do not have an isolation transformer you can use 630WVAC capacitor. For the ground put .47uF @ 630WVAC in series from the oscilloscope ground to the test chassis. This will isolate the oscilloscope AC from the chassis, but let Audio through RF pass to the input to the oscilloscope. If this is not clear I'll be glad to make a drawing.
@@AllAmericanFiveRadio thank you for your help, so,, to make sure i understood correctly, 1x630v .47uF in series to ground? I want to mention that i do not have an isolation transformer and the outlets in my house(except the kitchen) aren't connected to earth(for this application it might be a good thing) but i did just ordered myself a 375w light bulb to make a current limiter.
I want to use the scope to check ripple in the rectifier of my 5f1 fender champ that i build myself(i used a choke instead of a resistor so maybe 5e1), I want to mess around with different part values to get the cleanest dc power. The probes should be in x10 attenuation position, i assume, for that type o measurements?
@@seanambrose22 The capacitor goes between the ground of the oscilloscope and the ground of what your testing.
@@AllAmericanFiveRadio I understand, thank you you for your help
Hey, thanks for the great video, I have a question though. I have a large load (about 3 ohms) and I am building a supply for it where at maximum it would be running around 40 volts at about 15 amps, where I use a step down transformer and a bridge rectifier. I need to take very accurate current and voltage measurements on the output of the supply for the purpose of measuring efficiency, and I was wondering if I really needed to add a good filter in my supply or if I could just leave it rough.
Thank you.
Naice video
Thanks
Thanks 👍 شكرا
Thanks
Thanks juopotski
Hi I came across your video because I have some type of filter and someone showed me a link to your video trying to describe the filter I have but you’re talking about DC in your video but the filter I have is on the AC side incoming 120 V power in series and parallel with the hot and neutral feed into a microwave oven transformer a.k.a. MOT. I build projects with MOT’s and was wondering if having that filter in the circuit for projects other than the microwave does it affect in a positive way the operation of the transformer say producing any heat generated by inefficiencies in transformer or is it just the same running the transformer with hot neutral directly from mains? I’m not sure if I can post a picture here but if you have a way I could send you a picture of the circuitboard with the filter unless you don’t need one and you understand what my filter looks like.
Usually capacitors that are connected to AC are noise fillers.
that help me out with a problem. but still, I can't know how to smooth a transformer 600W 30V 20A ( 15v - 0 - 15v). I use 2 diode 30amp with (2 capacitors 25V 0.5 F that have board smooth current starter ) it helps good until the current reach 10amp and they start to collapse with the signal smooth. so I must have a way to create a shock filter that can smooth 20 amp but i don't know how to make it
www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm
Thanks jfeet28
A good place to start studying formulas for PI filter circuits would be to Google:
RC time constant
LC time constant
And the frequency for a half wave I think would be 30Hz and for a full-wave would be 60Hz.
Hope this help;
and thanks again.
I know this is 12 years later but for a full bridge rectifier wouldn’t the frequency be 120hz?
@@xlilsasuke4x One 60 cycle sine wave has two pulses, one positive and one negative. Fullwave has two positive pulses same amount of time.
@@xlilsasuke4x So that means it is 120Hz.
great sir. i did the same to my scope after your video.i try to make (actually improve) an LC filter for my mig welder.i did all the measurements of the capacitor and the inductor ,but its almost impossible to find any equations to put them in. i can find equations in radio or smps but here we have full rectified ac , so its not pure dc , but its not ac either. how can we calculate anything?
Thanks. This may help.
www.allaboutcircuits.com/tools/coil-inductance-calculator/
www.eeweb.com/tools/pi-match
Very helpful please can you tel me what coil do i need for 350V dc power suply. i heave build an Stereo amplifire with 2 x ECC83 (12ATX7) and 2 x EL84 (6BQ5)and i hear a 50hz noise in the speaker in the curent power suplay i have use two 50μf / 450v with an 1kohm resistor betwin cupasitors bat it seams not enough for filtering.
Does the HUM get louder when you increase the volume?
@@AllAmericanFiveRadio Yes that's correct
@@filippf12 If the humming varies with the volume, this means you are amplifying the humming. This may or may not originate from the power supply, you maybe picking the humming from something getting into the front end of your amplifier.
If the humming does not vary when you change the volume control this means the problem is in the filtering of your power supply.
There is a lot of help on the web nowadays, this is just one website to give you some ideas.
PI NETWORK IMPEDANCE MATCHING
www.eeweb.com/tools/pi-match
Hi sir very good video
Thankyou so much
I am looking for this type video
I am very interested
Thanks
Don't know, its a power transformer, it would be high though.
Thanks murphj4
Why is one capacitor 47 & the other 33 uF? Would this also work with two 47 uF caps? I have 50 Hz here in Germany ...do I need other values? 😞 I want to build a plate supply for various tube projects with 300, 250, 170 & 90 VDC. 💥 Is it possible to wind a choke on a big"Amidon" ferite core (chokes are hard to find these days😔) ...if so how many Henry or mH do I need? Bye! 🙋
Usually the first filter cap is higher in value. Has to do with RC time constant using a resistor, or LC if you use a Choke. There is lots of PI Filter Calculators now, its great. Google PI Filter Calculator. I like this one. EEWEB www.eeweb.com/tools/pi-match
i did some simulation on multisim(my objective was to create a voltage spike on the AC circuit and to reduce it), what i did was an ac source connected to a function generator to create a voltage spike on the AC circuit and it just so happen i just experimenting components and this pi-filter actually worked to it. The voltage spike in the circuit was remove with very little distortion in it and the output is still in sine wave. can you explain to me why did it worked to the circuit?
random modnar
czcams.com/video/y11SbmXPY18/video.html
great video....so if i am working on a amplifier with a 5U4 rectifier, and have replaced the filter caps, but still have some ripple[hum] i can increase the value of caps up to the design limits of the rectifier tube...and then add a choke to get rid of any ripple remaining? if so, what would the average value of the choke i would need?..thanks, bob
Thank you.
I would try it without filters first. If you don't get the results you want you can always add filters.
Great Rick! What is the value of the choke? how many milli-henries is it?
Thank you.
@@AllAmericanFiveRadio 😆
How do you calculate the value of the inductor and capacitor you used
GOOGLE pi filter calculator
Home of RF and Wireless Vendors and Resources
www.rfwireless-world.com/calculators/Pi-LC-Low-Pass-Filter-calculator.html
Low Pass/High Pass Filter Calculator
www.digikey.com/en/resources/conversion-calculators/conversion-calculator-low-pass-and-high-pass-filter
I wonder, would a tube rectifier circuit behave the same way?
Yes it would. Thanks!
I would add a regulator. Google "regulated power supply circuit"
please tell me if i need 22 volt 5 amp what value choke coil and capacitor do i need?
Chebyshev Pi LC Low Pass Filter
Calculator - Calculator Edge
www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm
Would I get your results with bigger capacitors? I need 36vdc @ 4A. No ripple. Two 4700uf
filter capacitors. Is the theory the same in just increasing the amount of capacitance?
Yes, and Thank you.
can Pi Filter, filter voltage spike? or high frequency noise?
By changing the components values and configuration, you can make a power supply filters like this, or high pass filters, or low pass filters at different frequencies. Just Google High pass or Low pass filer.
Really a voltage regulator. Forgot to say it is for a dual Class AB
amplifier board. Does that matter?
Thank you.
can this be used in a power supply for an amplifier rated 60 watts?
Pi filters are used in all kinds of power amps, and some that are thousands of watts. The components in the power supply and filter circuit are designed to handle the rated power.
Thank you
how can i calculate the value of capacitor and the choke?
Suphapong Nutwong
Google “PI Filter Calculator”
Why is the bigger cap on the input?
2017-07-13 13:40:49.10 GMT +7
RC Time Constant.
What value of inductor you have used in the video
13.42H
@@AllAmericanFiveRadio sir thank you soo much for your reply . I have one more question sir can i increase the value of capacitor and inductor to get good results .
@@kryptocat4240 Increasing the values usually results in better performance. There are many calculators for PI filters. You many be interested this. www.pronine.ca/butlf1.htm
@@AllAmericanFiveRadio thanks sir i am our new subscriber i loved you contents i pray for your success .
You only show the ripple voltage, what about the DC voltage???
At 6:05 it's a straight line.
why do the resistors cause the voltage to ripple?
The resistor does not have any Back EMF, I did a video on that also.
+Cadet Hassan The voltage ripple is not produced by resistor , ripple is produced by rectifier from AC to DC so before our filter - our filter role is to smooth the ripple . The capacitors + resistor + inductors have the role to smooth the ripple because they act like energy reservoirs .
The resistor is less efficient compared to inductor for smoothig the ripple .
A combinations of 2 capacitor in series with an inductor between is named PI FILTER because geometrically it looks like the greek PI simbol
Because V = IR. Less current can flow so in turn more voltage is produced. If you want an analogy, think of a constant volume of water flowing through a pipe. If the diameter of the pipe is reduced, the pressure must go up to compensate for the resistance encountered.
Thanks mznxb9872
Could you do a Twin-T Notch Filter? sim.okawa-denshi[DOT]jp/en/TwinTCRtool.php
Thank you.