Pulse Width Modulation Half Bridge MOSFET Driver TL494 2N2222 IRF510
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- เผยแพร่เมื่อ 5 ก.ย. 2024
- Since this video I have another setup for the LT494 that I like better. I just uploaded the circuit to my Google Diver, it is a JPG, so just click on the link.
drive.google.c...
Pulse Width Modulation Half Bridge MOSFET Driver TL494 2N2222 IRF510
TL494 Pulse Width Modulation Control Circuit
• TL494 Pulse Width Modu...
output 1 switches a mosfet on the high side, so source is not ground! it needs a bootstrap capacitor or isolated gate drive.
True
I like the 50K being able to adjust the best wave you need. And the way it uses all the energy in the push pull is pretty cool Rick.
Always interesting my friend.
Thanks.
When I first looked at this circuit I was scratching my head, how does this work??? Then I got the idea to substitute one of the MOSFETS with a wire and then I saw that one capacitor discharges through the primary. Then I did the other one and the other capacitor discharges. Then I saw the polarity. Then I saw that one capacitor charges while the other discharges. What an interesting and elegant design. I had show this one in detail. My friend Carl I hope things are good.
Thank you so much for your examples. You are an excellent teacher.
Thanks and your welcome.
Thank you for the video where you explained a lot about the function of the TL494.
Just for the half bridge with the two n-channel Fets you better take a high side driver (for 12V + Uth) or a p-channel Fet. In the current configuration the upper Fet is in source follower mode and will not be able to raise its source to more than 12V- Uth = 7.5V which will produce loss and heat it up.
Thank you for the video anyway.
True!
I am an Engineer and I learned somethings important in this treasured Video Big Thank you .
Thank you, and your welcome.
Lovely to see the waveforms.
Thanks and your welcome.
Thank you ,just the circuit I've been looking for.
THANK YOU!
Did you deliberately set the switching frequency at the transformer-capacitor resonance?
Thanks for clean and clear explanation.
Yes, that gives the best results. Thank you.
Very interesting as always! Greetings from Slovenia and best regards in these hard times
Thanks very much. Best of regards, Rick
pin 4 dtc works from 0 (minimal 3%dead time 47% duty) to 3V (max= no signal)
True
Might I suggest you try using a PIC121572 microcontroller to do this PWM generation. This IC is 8 pins, has 3 phase PWM with 16 bit resolution and an A/D converter you can use to go to that 50k pot to change duty cycle. I have used this IC for fan controllers and several other applications which are more sophisticated.
Thanks.
I'll take a look!
I think using a PIC121572 microcontroller is not straightforward like TL494. It needs programming experience. Could you please guide us for programming? How much does it cost for PIC121572?
Even though micro's are cool and can do alot of stuff. I would avoid using a micro like the plague. There is already a pot to change the duty cycle and if it's a matter of varied V+ based on temp or anything else a resistive sensor is all that's required. You create a voltage divider network and voila! Your in like Flynn or as they say down below "Bob's your Uncle.
@@reclaimfilterssystemsinc7529
I would avoid using a micro like the plague.
WHY?
If you can do the same thing with hardware, it’s simpler, often faster, more reliable and less costly (in most instances) when you have software running this type of circuit the PID loop can be slow, over reacting or even glitchy. It can be done and we have done it in several of our HV power supplies and they are ok and even good, but the boards are crammed, the high voltage emf and spurious emmisions, can and will wreak havoc with your micro if your not careful @@rammisframmis8588
First class video and excellent explanation. Thank you.
THANK YOU!
Very informative, as always. Great video!
Thanks Andrew
Muy bueno, lo voy a armar para jugar un rato, gracias por compartir!
Thanks and your welcome.
AS ALWAYS GREAT VIDEO, THANKS
Thanks and your welcome.
Great video! Thanks!
Thank you, and your welcome.
Very nicely done video, Mr AA5. It looks like CT = 1nF and RT = 100k which for push-pull would yield freq= 1/(2*RT*CT) = 50kHz/20us. But your 'scope display says "5us" with ~5.8hdiv/~. What frequency are you actually operating at? What kind of transformer is that? Thank you in advance.
Thanks.
The frequency is 34.6kHz. The transformer is an audio output transformer make for a 1920's vacuum tube. A 71 tube or a 45 tube.
Was wondering if faster transistors were used or mayhaps different capacitor values to create sharper leading pulse edges?
@@gregjones3660 Thanks.
Changing capacitors would have the most influence on the shape of the pluses.
Sir Nice video, many thanks for uploading. Can we use the same circuit and duty ratio adjustment for a single switch converter? Or do I have to modify it?
If you need a Pulse Width Controller it should work. Since this video I have another setup for the LT494 that I like better. I just uploaded the circuit to my Google Diver, it is a JPG, so just click on the link.
drive.google.com/file/d/1xIIu6gHfpzzQuLbAZ4FZnSZ4Eeb7ARM6/view?usp=sharing
Very nice. Many thanks for your help. Excellent!
@@mbashir42 Thank you, and your welcome.
Your videos always provide some clarity, I’m currently working on a Class D Amplifier final year project and I am using 2 IRF540 N channel Mosfets . However I am struggling to drive my MOSFETs as I first tested them without using driving(used the PWM signal directly to my Mosfets) but this did not work and my Mosfets kept on overheating .
I was advised to use Pulse transformers to drive my Mosfets so that I can have a positive voltage VGS and be able to increase my supply voltage to 40V-70V. Your help will be highly appreciated regarding this.
What can I do to ensure that I am able to increase the supply across my upper mosfet and still have a sufficient gate voltage to turn on my Mosfets?
Are you working on a half bridge power supply? I will be glad to try and help. Please using my email allamericanfiveradio@yahoo.com so i can send you information. Also you can send me the circuit you a working on.
Done!
Very interesting!
Btw, little spelling error in the video title (plus -> pulse )
Thanks, I made the correction.
I have subscribed and if you can post a video tutorial on how to regulate current and voltage outputs that would be great.
I'll keep this request in mind. I do have two videos that are related to your request. Here are the links.
Discrete Transistor Constant Current Source Circuit
th-cam.com/video/eHGumuqh--Y/w-d-xo.html
Adjustable Voltage Regulator LM317T functional demo
th-cam.com/video/2TZZX9FOMmM/w-d-xo.html
Hope this helps.
I am confused. How do you get a sinusoidal wave out of a square aware by just going across the transformer ?
That is one of the things a transformer does. It transforms.
You are joking right?? A transformer only increases or decreases an AC signal depending on the primary and secondary winding ratio. I have never heard, read or seen a case where a transformer by itself magically converts a square way into a perfect sinusoidal wave. You have to be joking in your comment.
Does the circuit turn the mosfet on properly with no heating up at no load with high amp battery connected
The gates are biased with about 12VDC to turn them on fully, the MOSFETS will still get warm. I would suggest using IGBTs. IGBT is full on with the gate at about 4VDC. here is a video I did on IGBT.
Insulated Gate Bipolar Transistor IGBT IKP06N60T
th-cam.com/video/mL14VfjueIo/w-d-xo.html
Wow thats a perfect sine wave, is that whats coming out from the Ttransformer outp
Thanks! That is the output from the transformer.
Hi, i has a half bridge using tl494 like this, but when I measure the waves like you, the output is an AC square wave according to duty, not a sine wave like you, is it correct?
The sine wave is out of the transformer.
@@AllAmericanFiveRadio after all, i checked everywhere and i think your transformer winding too much and the inductance is very high, so that's why it's sine wave, it good to see in oscilloscope but put the heavy load will get your voltage dropout.
@@giangvo2746 The transformer is an 1920s inter-stage audio transformer.
@@AllAmericanFiveRadio oh, I thought you used a pulse transformer smps : )
Thank you
Thank you, and your welcome.
How High Side work without Boostrap Diode and Capacitor ???
This circuit will not produce any usable power. It is for demonstration only.
The waveform at the output of transformer is bigger when you increase the voltage in pin 4 or pin 3? Thanks
Thanks and your welcome.
hey my friend I need to make a square signal that have not any small changes in frequency or pulse width but ics like 555 timer can not be like that and have small changes is there any way???
I hope these videos help
555 Timer
th-cam.com/video/QH9iKOM-wGY/w-d-xo.html
D Flip Flop Clocked with 555 Timer
th-cam.com/video/l5MM9-rt8b0/w-d-xo.html
Is a Step Up Transformer or a Ferrite transformer? Thanks
I used a 1920s inter-stage transformer, step-up.
hi..sir i saw your video..and you are so profesional...bravo...sir i have question..i want to know what is error amp on t494??
This information is from the PDF
APPLICATIONS INFORMATION
The pulse width modulator comparator provides a means
for the error amplifiers to adjust the output pulse width from
the maximum percent on−time, established by the deadtime
control input, down to zero, as the voltage at the feedback
pin varies from 0.5 V to 3.5 V. Both error amplifiers have a
common mode input range from −0.3 V to (VCC − 2V), and
may be used to sense power−supply output voltage and
current. The error−amplifier outputs are active high and are
ORed together at the noninverting input of the pulse−width
modulator comparator. With this configuration, the
amplifier that demands minimum output on time, dominates
control of the loop.
www.onsemi.com/pdf/datasheet/tl494-d.pdf
Dear sir I try to make such circuit but I do not know how to connect 3 pins of 1M ohm potentiometer with other 3 pins of 50K ohm of second potentiometer (SKITCH part upper left hand side for connecting 1M with 50K not clear to me ) kindly I request your support regards
The 1M sets the limit, usually a value of about 15K works nicely. The 50K varys the output from the limit to the max.
I prefer this setup of the TL494. Unlisted video.
th-cam.com/video/PkwqwKPnFpA/w-d-xo.html
Thank you so much for your knowledge, please tell me details for your transformer and capacitors, i just move in power control world and your components are radio world ones, the transformer is special? in theory must be satured...... look like simple transformer not ferrite one, ...... the capacitors are ac 600v?......some power requirements........I ask ,power output in watts .......thanks I try your circuit.
best regards
My purpose for this video was to explain how the half bridge MOSFET driver works. You would need a high-frequency transformer to produce usable power. I searched for this circuit and found several, but none of them explained how the circuit works. If you'd do a search on the half bridge driver you'll find usable circuits. But none of them explain how they work.
What kind of transformer? core material? Turns ratio?
I used a Signal Transformer DP-241-4-16.
To get high voltage you need to use a ferric core high voltage transformer.
Thank you for the video, can the output pulse reach 90%, as I have an application that requires overlap?
If you want overlap use the output directly from the TL494.
Sir,
If there are no signal pwm on pin 8 & 11 , but there is signal saw tooth on pin 5 (CT pin) 30kHz, what's the problem?
There's alternating pulses at pins 8 and 11, and a saw tooth at pin 5. Did you witch the video?
@@AllAmericanFiveRadio Not on your videos, Sir, I think pin 5 is an oscilator that generate square wave on pin 8 & 11. I'm trouble shooting my welding machine, that use tl494 chip, I searching basic operqtion tl494 & luckily found your videos.
Thank You for reply & videos, Nice video anw & sorry about my Bad English
@@TheJavaSync Check the power to the chip. Usually capacitors fail before the chip. The chip is working the output MOSFET's or IGBT's could be bad. In circuits this it's possible to have more than one problem. Good Luck!
This does not work at low frequency like 60hz Only at high frequency of khz.
Yes you are correct. The TL494 specifications recommended operating conditions for frequency are 1 to 300 kHz.
If you are looking for a slower running circuit you might try this IGBT circuit.
IGBT Astable Multivibrator
th-cam.com/video/PnAiAhZH9hw/w-d-xo.html
Dear sir I try to make such circuit but I don’t no how to connect 1M ohm potentiometer with the 50K ohm potentiometer ( how connect 3 pins of 1M ohm with other 3 pins in 50K ohm) kindly I am looking for support regards
hello how do adjust the frequency to get 50Hz? I am currently building a project that require me to have 50Hz. (SA standard) thank you in advance
To get 50Hz you would change the RC time constant and the Vcc. Download the PDF for the TL494 to get the Electrical Characteristics, Oscillator Section.
You might look at a 555 timer.
555 Timer
th-cam.com/video/QH9iKOM-wGY/w-d-xo.html
@@AllAmericanFiveRadio okay thank you.
@@AllAmericanFiveRadio and I am using Multisim and Psim to simulate the circuit before I order the components, but i keep getting a square wave at the output. which simulation circuit do would you advice me to use sir. I thought of just using faith and build it but i only get one shot at this.
@@thusananisilent6141 Since the frequency you want is 50Hz I would add a small power transformer to the output. Like 120 ac in and 6.3 ac volt out. Try using the primary and/or the secondary. I used a transformer to achieve a nice sign wave.
Protues didn't show the sine wave
Simulations are limited.
Thanks. Interesting and well explained. Im Gods Gods Servant David - Isaiah 55 NIV and my focus is on Gods Kingdom - Actual thus my mental focus is on that. People like yourself are able to dedicate your full mental capacity to yr field - to see what i dont have the patience or focus to see ...efficiently.
Thank you.
is CT transformers?
NO