Welcome to my Channel! I am an electronics enthusiast, soldered my first blinky light when I was 10 and made a great career out of it, which brought me to all corners of the world. Still enjoy tinkering, soldering and coding, when I am finished with it I will put it on RU-vid. Enjoy!
Awesome technical content, theory and practical science meet here ,thank you very much do you have any future plans to make a video about h-bridge or bldc mosfet switching performance, similar to your MOSFET series
Hmmm, sure its one way. You could use one or two super cheap transistors, a logic gate, a schmidt trigger, a comparator, an opamp, all sorts! but its OK that you did this.... but its not the only way. The right method depends on space and cost limitations.
Really great and explanatory video ı really liked your explanation. But what happens if we were to do like an H bridge configuration? This time we need drain voltage + gate thresold voltage to use the mosfet on the High side right? That would mean 12v is not sufficient and maximum 16v rating of ne555 is also not sufficient. Or am ı wrong can you please answer me ı don't know and ı am just asking.
Thank you! For H-Bridge you will need to make a bootstrap supply of 12V like in this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-M5lETaqI9JM.html. Suggest you use the IC solution, much easier and robust. You can also use a motor drive IC like ST's L293D for low voltages and frequencies.
@@smartpowerelectronics8779 ı am trying to design a brushless ESC with microcontrollers and wanted to make a H bridge first. Most Motor driver IC's cannot handle a lot of current and voltage and ı don't want to throw an IC to the problem to be honest ı want to learn how to do it myself. But Thanks for your answer you have some really good content. ❤
So as far as the mosfet is concerned its just seeing the npn and pnp switching transistor in the 555. I would just use a a pair of transistors and not waste a 555. in fact real mosfet driver IC's are possibly same cost as a 555. saw a guy use some optocouplers a few years ago for driving P channel fets from logic lines.
You are clearly a professional! The transistor pair will give you the current gain, however for the voltage gain you need a 3d transistor, see this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-wv4uAz8FV2w.html .
If you take a complementary pair - say BC547 and BC 557, and put them in emitter-follower, you can achieve the same effect with - Lower pin-count - Lower cost - Lower quiescent current - Better performance. 555s are good to learn the basics, as illustrated in the fantastic book by Forrest M. Mims III, but let's leave it at that.
The totem pole will give you the current gain, for the voltage gain you need a 3d transistor, see this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-wv4uAz8FV2w.html
No, let's not "leave it at that." It's better to have knowledge of all the different ways to use all the tools in your toolbox (so to speak) as you can never anticipate all the circumstances that can arise. Maybe you're in the middle of a build and don't *have* BC547 and BC557 transistors available, nor any kind of dedicated MOSFET driver... but do have a box full of 555's. Then it could very easily be the case that the 555 is the perfect solution - in context. I don't think anybody is saying that a 555 should be the MOSFET driver of choice, but knowing that it's capable of performing that function is potentially a damn handy bit of knowledge. It's just another arrow in the quiver.
Maybe the NE555 drives a serial RS232 with 12V = Low and 0V = High? Or an ATMega HV programming? This requires 12V on the reset pin of the ATMega. Then you can still delete the program from a locked IC and reset the fuses to normal.
Good idea, it is fast enough for RS232, I have never tried Atmega HV programming, did not know you can use it to erase a locked IC, so I learned something today, thank you!
This doesn't work with the B555 from GDR production. On the NE555, the Set input is overruled by the Reset input. However, with the B555 the Reset input is overruled by the Set pin. The reason is that the NE555 takes the /Q output from flipflop and inverts it again in the driver stage. That's why Reset is dominant. However, the B555 takes the Q output from flipflop and does not invert it in the driver stage. That's why Set is dominant. For most applications, however, this difference is irrelevant. Most 555 clones do it like the NE555.
Thank you, you seem to be an NE555 expert! I tried all the 555's I had lying around and they worked OK except the TLC555, but there are many variants of the 555....
It’s possible to use 555 in a high side driver for 12v, just use one more 555 as a voltage doubler with diode and capacitor. So using cheap PC817 optocopler we can switch +12v high power loads
You can connect 555 DIS to Q and get even more current to close MOSFET Gate faster. Usually MOSFETS drive inductive loads so fast close is more important than fast open.
im quite confused when you said you were gonna build the circuit. i just saw a load there with a reverse diode, then you added a transistor and stuff. i got lost after that point.
The transistor, 4k7 resistor, zener diode and the 100nF capacitor are added to make 12Volt for the NE555. You can also use a lab power supply for that. I wanted to show exactly how I test the circuit to make sure I show the actual performance :-)
Hi Steven, these are circuits from my memory from the 90's, I just verified them by simulating and building them. I did not have practical experience with the 3d circuit (cascode), I heard of it before and found one reference here: electronics.stackexchange.com/questions/264142/drive-a-mosfet-via-bjt MOSFET driving is very specific knowledge, so it is not easy to find good reference information. You can check application notes of Texas Instruments, they have some great material like this pdf: www.ti.com/lit/ml/slua618a/slua618a.pdf?ts=1722369784772
Was it the 3d circuit? (cascode with 2 x BC547) Please check the 12V supply and the transistors (Take the out & check B-->E and B-->C with multimeter diode test mode, should be 0.6-0.7V). When all parts are ok, also voltages make sense, connect the input to 12V, then to 0V (gnd) and check the output (with a LED+2k or mutimeter) - does the output go up and down?
@@smartpowerelectronics8779 And for other users that run into struggle I forgot to mention that plug and cable for the logic analyser have to be USB 3.0 .... Under USB 2.0 my trials failed badly.
i have a problem...in my circuit im using a LM358, basicaly its composed by 2 op amps and 2 power pins, v+ and v-, the problem comes when i add this ic to the schematic because it appears just as an opamp and not the whole ic and now that im designing my pcb those connections, v+ and v- actually arent connected and i dont know how to fix this...im new
Hi zFrank, When you place the symbol, you can select opamp A or B (click ">" next to lm358) you will find that except Opamp A and B there is a Unit C which is the power pins ;-)
Thanks you for the detailed explanation. I just want to add a comment that MOSFET turn on and turn off speed is the time the transistor changes state. In most of the video, you are referring to the shifter delay as turn or and off time but this is just the shifter delay and not the turn on/off time. While important to prevent shoot through and ringing, the delay time is not as critical as the time the mosfet spends not fully on or off.Power dissipation is current x voltage and partially open time is where most of power loss is generated. One of the most important characteristics of the mosfet driver is how fast it can switch the transistor. In that respect the slope of the open/close curve is more important than the shifter delay. If you measure it in your experiment you will probably find out that the IC does that best and will result in least power loss.
Very bad tutorial. Thank you because I learned lot of stuff. However you did not explain many things, like model or name of footprint, and many options you selected. You inserted a pin header and in the final PCB is is shown as DIP8 Socket. What? yep. You skipped steps. you selected the X and Y unnecessarily in 2 or 3 instances.. Everyone is cheering you up, but can anyone produce the PCB you shown? I dare anyone to say they did.
sorry to hear that, it is only a quick guide how to use KiCAD, there is a link in thedescription with the design files, download, unzip & double click the .pro file you need.
Can I use these circuits to swap batteries? I would like to keep a second battery full until the fire battery is exhausted. After that I want to turn on the power from second battery and jettison the empty battery. But this means that after battery swap the second battery would power everything including the control circuit.
@@smartpowerelectronics8779 The one from the link is not really good for me. The current will be like 80Amps continuous and I have no space for a heatsink. So I am still looking for some low Rdson n-mosfet that will be under 1mOhm.
Hello. Can you tell me how to choose an arbitrary orientation for my track in kicad, for me it is always at an angle of 45 degrees and I want it to be at an angle of 90 degrees, is it possible to do something so that I can change the angle of the track over time? work, for example, like in Sprint Layout when you press the space bar?
Hi Maxichannel, when you are placing a track you can right click and change the track angle mode. Or (better) use the shortcut: press <crtl> + </> to change the track angle mode, it will toggle from 45 degree to rounded, to 90 degree.
10uF cap needed only for Nano as programmer? That was not made clear. I am using an Uno as programmer. Complete failure and frustration until I removed it.
