Its the next thing to do in my list and I will do it.

I have those as well, 100pcs of IRFZ44N. Will it simplify the circuit (not so many transistors) ?
Can you draw for me the mosfet version please?
- Thank you officially for your extraordinary involvement and real help ! I really enjoyed working with you.
You are an awesome person. I assume you are from america, your info doesnt tell. You have the right 'accent'. Haha.

You would need 4 P Channel MOSFETs as well unfortunately, to replace the upper bipolar transistors. To use N Channel ones there becomes more complicated.

And no, I'm in England.

 

Something is wrong. Unless you are using the output of he regulator to power the motor, it should not even get warm.

---I know--- and I was experience a literally shait storm, having these expectations in mind. It definetly didnt behave as I imagined/designed. I struggle to first make it work for more than 12h possibly even 18h. Until I realized what I did wrong and then it worked. But at the terrible cost of unexpected overheating border circuit components. I clearly have a fundamental gap in my knowledge about something. It might very much be this multiple transistor arrangement in the end of the cct as discussed so far. Maybe the mosfets will simplify the number of components used.... I expect it to.

 

You would need 4 P Channel MOSFETs as well unfortunately, to replace the upper bipolar transistors. To use N Channel ones there becomes more complicated. And no, I'm in England.

- Aaaah, I knew it will bite my ass some day. Haha. I just look and I do NOT have any P channel power mosfet. I have smd ones but not big powerful ones. Not even scrapped !!! So dark. We will have to do it with N-Ch mosfets then.
- But I have a lot of scrapped (not new) PNP power BJT though ! Cant we use them interchangeably ?
I am really towards efficiency and proper power dissipation, to be bluntly honest. I dont care how big the cct is.

 

I simulate with all N-ch Mosfets and is working for very low speeds in the simulator:

But I believe you are very right, i will need some P-ch Mosfets for the Top side. The history will repeat If I will not use them correctly.
I do have PNP power BJT's, but are all scrapped, not new. I will try some with this circuit that I have right now on the breadboard and after that I will switch to the mosfets.

 

Hello,

Have a look at the following kit in the PDF.
It contains a circuit with a H-bridge driver using fets.

Bertus

 

To @bertus that is a cool circuit using opamps. Very cool.

 

I simulate with all N-ch Mosfets and is working for very low speeds in the simulator:
View attachment 278648
But I believe you are very right, i will need some P-ch Mosfets for the Top side. The history will repeat If I will not use them correctly.
I do have PNP power BJT's, but are all scrapped, not new. I will try some with this circuit that I have right now on the breadboard and after that I will switch to the mosfets.

If you use PNP power BJT's you will have to use the inverter transistor that I show in post #71. I've attached a modified file to show what I mean, and amended it to show 5V power to the 4017.

No, unfortunately you can't use N Channel MOSFETs for the top side that way because you cannot easily drive their gates the required ~10V higher than the motor +Ve supply, which is needed to get them to turn on properly.

Just modify your existing circuit as I showed in post #71, since you know your NPN transistors work.

Don't push your motor voltage too high because you don't have anything to control motor current in your circuits!

 

Just modify your existing circuit as I showed in post #71, since you know your NPN transistors work.

I stay and think of it a bit and I will make it from BJT's because I have a lot of them. I have less mosfets compared to BJT's in my arsenal. So I will proceed with your cct as you show here.

Don't push your motor voltage too high because you don't have anything to control motor current in your circuits!

Thats interesting !

EDIT: I've just realised that I've drawn both this cct and the one in #71 wrong. The 2 driver inputs SHOULD be connected together to ONE Qn output, not as shown.

Digital drawing is NOT as pleasant or fun or EASY as it may appear. It is very much software dependent and you have to really know your software like instinctual good, to be able to really get some good results and consistent and easy enough. Im speacking from 20years of Adobe Photoshop !!! Not from yesterday. The most easy solution is using either a simulator program and printscreen it like I often do, or simply draw it on paper , take a picture with your phone and thats it. I do that as well. Hopefully will help you see others experience in the digital world.
Here is the corrected cct:

 

I stay and think of it a bit and I will make it from BJT's because I have a lot of them. I have less mosfets compared to BJT's in my arsenal. So I will proceed with your cct as you show here.

Thats interesting !

Digital drawing is NOT as pleasant or fun or EASY as it may appear. It is very much software dependent and you have to really know your software like instinctual good, to be able to really get some good results and consistent and easy enough. Im speacking from 20years of Adobe Photoshop !!! Not from yesterday. The most easy solution is using either a simulator program and printscreen it like I often do, or simply draw it on paper , take a picture with your phone and thats it. I do that as well. Hopefully will help you see others experience in the digital world.

Purely a brainfart on my part! I'm so used to seeing H Bridge circuits where the upper and lower halves are driven separately that I instinctively let my fingers draw the 2 halves that way. Make sure you connect them together as per post #87 corrected.

 

Erase the bad one and leave only the good one. Its too confusing otherwise. And leave a note that is edited and thats it.
And thank you ! You are awesome.

 

Erase the bad one and leave only the good one. Its too confusing otherwise. And leave a note that is edited and thats it.
And thank you ! You are awesome.

Done, to both posts.

 

Ive built your circuit and it doesnt work.
I get a High spiked pulse on Out2 and Out4

And a low spiked pulse on Out1 and Out3

The motors tremble but not spinning.
The circuit, as complicated as it is, gives signs that is working.
I noticed at 5V, the PNP power transistors are getting very hot ! All the power is on them.
Here is to wonder on the complexity of this cct.

The motor attached to the circuit in the picture, is the scrapped one. It is a bit more sensitive than the new one. It moved more evidently for lower voltages. The new motor, like a square black box in on top of the image and is less sensitive, it does tremble but very fine, extremely little.
The 5wire (the one in the middle) is not doing anything.
It appears the power is LESS than in previous circuit that was also LESS than the original direct circuit where I burned the IC's.
Is on a decadent power curve. Less power reach the motors and too much of it is wasted on the transistors.

 

Ive built your circuit and it doesnt work.
I get a High spiked pulse on Out2 and Out4
View attachment 278754View attachment 278751
And a low spiked pulse on Out1 and Out3
View attachment 278753
The motors tremble but not spinning.
The circuit, as complicated as it is, gives signs that is working.
I noticed at 5V, the PNP power transistors are getting very hot ! All the power is on them. View attachment 278758
Here is to wonder on the complexity of this cct.
View attachment 278756
The motor attached to the circuit in the picture, is the scrapped one. It is a bit more sensitive than the new one. It moved more evidently for lower voltages. The new motor, like a square black box in on top of the image and is less sensitive, it does tremble but very fine, extremely little.
The 5wire (the one in the middle) is not doing anything.
It appears the power is LESS than in previous circuit that was also LESS than the original direct circuit where I burned the IC's.
Is on a decadent power curve. Less power reach the motors and too much of it is wasted on the transistors.

I can't really make much from the photo, it's too difficult to see everything.

To start, can you show me scope pix of the 7404 output pins and of the collectors of the single NPN transistor which connects to the 4017 via the resistors, please.

 

RE:""100pcs each, we can use in parallel for dealing with greater power if needed""
Dont even dream about. How many pieces You will use parallel, so many fold each of them will become slower.
And stepper is one aggregate demandous about speed.
Okay, may put some 2 or 4 parallel if they are under naonosecond transistors, but microsecond already have wholekillingly effect. And vice versa, if put 100 parallel, the result will turn out be catastrophic.

 

To start, can you show me scope pix of the 7404 output pins and of the collectors of the single NPN transistor which connects to the 4017 via the resistors, please.

I probed all those 4 pins before the diodes, pretty much directly from the output of the 4017

I got the exact same result/ waveform as this picture, for all 4 pins. I also believe they are like in the simulation, one after the other for each pin/led that is lighting.

 

This is one of the signal directly on one of the output of the NOT gate 7404
Its the same for all 4 outputs, I check them all. Up until here is fine.

That is a very nice inverted square wave. Probably the first I watch them on my DSO. Cool.

 

hi q,
A point to be aware of when using TTL gates, if the input is not connected it will assume a High state and the output will be Low.
Those 1N4148 could cause a problem by not pulling the 7404 input low, to switch it.


E

 

I probed all those 4 pins before the diodes, pretty much directly from the output of the 4017
View attachment 278764
I got the exact same result/ waveform as this picture, for all 4 pins. I also believe they are like in the simulation, one after the other for each pin/led that is lighting.
View attachment 278765View attachment 278766

I built my circuit exactly as in post #71 (with NPN power transistors at the top) but without the items in the box since the 4017 is powered from 5V. Like you, I found that the transistors get very hot, and in my case my power supply goes into current limit at over 1.1 Amps.
I think the problem with these circuits is Shoot Through, with both upper and lower transistors in the same leg being on for a short time as we switch from one direction to the other.
By the way, my build didn't have any of the diodes or LED's and resistors, etc, that you show in yours, just straight to the 4017.
Must go now, dinner time again!

 

By the way, my build didn't have any of the diodes or LED's and resistors, etc, that you show in yours, just straight to the 4017.

No protection, No IC's. I learn my lesson. Haha.

I built my circuit exactly as in post #71 (with NPN power transistors at the top) but without the items in the box since the 4017 is powered from 5V. Like you, I found that the transistors get very hot, and in my case my power supply goes into current limit at over 1.1 Amps.

My transistor cct is quite stable in current than yours. It remains at around 250mA with NO motor attached, and it goes to 300mA for both 4wire steppers. This cct may be more balanced probably.The other cct was having light current difference between motors used. IF I switch the motor between them, not in the proper wire arrangement, the current jumps to 500mA sign that the motor is wrong connected !!! Re-check all your wire connections for that clear short you have there that goes to 1.1A.
I have a special 'port' for each motor !!! (I am not using the same port for all the motors). Each port has different wire permutations to fit a specific motor coil configuration. See the image:


I am using this Old cct because I didnt re-draw all those transistors cct yet. Those 2 top from Left - PNP Power transistors they get excessively hot in my case. In the previeous cct with all NPN's the bottom 2 were getting hot, still on the Left flank there.
My assumption is that I am using
- 1 not powerful enough transistors
- 2 not New and Good, but old and scrapped and possible deteriorated PNP's. Because is all I have. I only have brand new NPN's, as I said.

I also recalibrated your multi-transistors cct , and is driving a BIT more current than originally was, but to the expense of overheating a bit more the power PNP's. The motors are a BIT more powerful. But Not even close to the other precedent circuits !!! Compared to them, it is still weak and also not rotating but only trembling.
We need a more serious cct than these.