MaxHeadRoom
- Joined Jul 18, 2013
- 28,682
Superior Electric no longer are in the stepper motor business AFAIK, I still have their Design Guides for stepper motors from the '70's.
They made both DC and AC variations. Nice products.
Stepping Motor Angle Rotation using Logic IC's
- Thread starter q12x
- Start date
They made both DC and AC variations. Nice products.
Let us start with full stepping on a 4-phase motor. Let a logic 1 stand for a phase which is energized and 0 for a phase that is not. What are all the combinations of four phases, energized two at a time?
From this table you can see a succession of states that repeat as long as you are moving in the same direction. To reverse direction, you go through then entries in reverse order. Thus, suppose the sequence 9, C, 6, 3 moves in the clockwise direction. It follows that 3, 6, C, 9 would move in the counterclockwise direction.
From this you can build a state machine that will execute these transitions. Now note that each of the columns has the same pattern of 1's and 0's displaced by 1 position. This suggests that a shift register initialized to a particular value and clocked appropriately will replicate all four values without the need for any external logic.
| Step #/Hex | A | B | C | D |
| 1 -- 0x09 | 1 | 0 | 0 | 1 |
| 2 -- 0x0C | 1 | 1 | 0 | 0 |
| 3 -- 0x06 | 0 | 1 | 1 | 0 |
| 4 -- 0x03 | 0 | 0 | 1 | 1 |
From this table you can see a succession of states that repeat as long as you are moving in the same direction. To reverse direction, you go through then entries in reverse order. Thus, suppose the sequence 9, C, 6, 3 moves in the clockwise direction. It follows that 3, 6, C, 9 would move in the counterclockwise direction.
From this you can build a state machine that will execute these transitions. Now note that each of the columns has the same pattern of 1's and 0's displaced by 1 position. This suggests that a shift register initialized to a particular value and clocked appropriately will replicate all four values without the need for any external logic.
MisterBill2
- Joined Jan 23, 2018
- 18,463
Certainly there is a mindset that wants to follow recipes rather than thinking and would much rather program a toy than adjust a simple comparator circuit. Actually designing in the real world instead of code does take more insight than following recipes. Superior Electric would not be found on amazon because they only used distributors who could offer assistance, which is totally outside of the amazon business plan. I will need to check my ancient archives to see what information I might have.
MisterBill2
- Joined Jan 23, 2018
- 18,463
THis sequence could be provided by decoding a binary counter, and that was done with TTL back then. It drove four big power transistors. If Max has the books then the answer may be available.
I imagine there must be some magazines or circuits compendium from old days or not so old.... is my thought... the hard part is actually finding the right one through hundreds or thousands of ccts... I do have a lot of circuits books myself but I will not open them if you will pay me. Its a jungle. Im too comfortable with google ! In truth.
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MisterBill2
- Joined Jan 23, 2018
- 18,463
When I do a web search for information I find the major selling sites instantly claim to have it without knowing what it is, even. And I am not interested in those who claim to sell data. So very seldom do general searches provide useful results for me.
The items mentioned by Max would not be on the web, but scans of manual pages are quite different.
