About Stepper Motors

[_q12x_]

There are two more pins for the address on yours A11 and A12 to address 64k rather than 16k since 2exp2 is 4.

Im not sure how your math works but here is my math:
2^16 = 65536 bit combinations (your chip)
2^64 = 1.8446744e+19 which is 2 quatrilions probably of bit combinations. And not 4 like you calculated. Haha.

 

[marconi]

Im not sure how your math works but here is my math:
2^16 = 65536 bit combinations (your chip)
2^64 = 1.8446744e+19 which is 2 quatrilions probably of bit combinations. And not 4 like you calculated. Haha.

16k memory locations is organised as 2048 x 8 bit memory locations shortened to 2k x 8 bits = 16k. 2exp11 = 2048. Address word A0 to A10.

64k is 4 x 2048 x 8 bit = 8192 x 8 bits = 8k x 8 bits. 2exp13 = 8192. Address word A0 to A12.

 

[_q12x_]

Aha... I believe this number 2048 and 8192 are referring to the Addresses/or/MemoryRegisters of the IC.
I think I get your point. Im not used to think in these terms, I still lack some experience but im not far away. Thanks for your kind explanation !

 

[marconi]

https://ww1.microchip.com/downloads/en/DeviceDoc/doc0270.pdf

 

[_q12x_]

https://ww1.microchip.com/downloads/en/DeviceDoc/doc0270.pdf

- I open it before I buy it. Im always reading the datasheet, I got used to it and is a routine now for me.
Good thought but im doing it all the time. I didnt read it corner to corner, I only fly over it, I smell it. Haha. Probably I will, in the future.
- For now I showed you that your influence grow with me. I liked the IC especially after that HARD circuit I made, also with your help, I realized it is a very good chip to have. And it was quite cheap anyway so I made the step and took them. How I will use them... we'll see in time.

 

[marconi]

Actually there is another forum discussion until reaching this cct here. It was an entire evolution of it.
This cct is working ok but in certain parameters. It is limited to power and heat over the Tr's.
Is working fine in the 5V range for 2 of my stepper motors that I tested with it. But if Im bringing up the voltage, to 10V, I get 140dgrC on one Tr and about 60dgrC on a few others. At 5V, everything stays at a constant 50dgrC which I call it normal and safe.
One of the test motor is a Nema17 17HS4401. The other one is a scrapped stepper. Both work fine at 5V and even at 10V, no one was heating. Over 5V, especially at 10V, only the driver's Tr's were cooked to (almost)death. I stopped the power after smelling hot metal in the air.
I am also receiving a couple of L298N IC's. They are coming in the mail, not arrived yet. But I dont expect much difference from them, compared to what I have here. It would be nice to be better ! I hope so.
- My question:
- How to make this cct more powerful? To drive more power through the coils of the stepper motor? (and not blow up it's Tr's!)
I already have 2 answers to this question in my mind, but I dont want to influence your answer. I expect to be pleasantly surprised. Haha.
View attachment 102851Thank you !

Pondering the circuit at your #1, I am doubtful whether when the CD4017 output is logic 0 that the inputs to the base of the upper transistor and the input to the NOT gate are pulled down to 0V because those 4 diodes, one on top of the other, are reversed biased so no sinking current can flow through them. The diode path can only source current which raises the potential at the base and input to the NOT gate - not lower it. I would insert four 10kR resistors as I have indicated in the attachment to provide a current path to the 0V rail when the input to the diode is logic 0.

 

[_q12x_]

I would insert four 10kR resistors as I have indicated in the attachment to provide a current path to the 0V rail when the input to the diode is logic 0.

-I actually did that in my experiments. Here are my results: In the simulator, I got a very small performance boost in the motor spinning. Almost negligible. In reality, nothing really looked different. With or without those resistors, the motor(s) were driven the same. I put 100k indeed there, in all my experiments. But I put 10k and 1k and the result was the same so I decided to go quite up in the resistor value since the performance and the result was equal in any circumstance.
-Your explanation is very pertinent and I like it. I may try it again and see if indeed something improves.
Well done with figuring how to draw over an image ! I know it is hard to do it for you. But it pays off, doesnt it? Heh. I cna teach you some advanced image editing stuff, since you know me, Im actually a digital artist and not someone who aspire to be one. Anytime, my doors are open to you.

 

[_q12x_]

Project is finished and working !

 

[_q12x_]

Project is finished and working !

 

[marconi]

Well done!

You could turn it into a clock.