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J Tiers
05-19-2008, 01:20 AM
In with a bunch of other stuff I got recently were some boards from a company "Alpha Products"..... A "DA-147" D-A, an "ST-143" stepper driver, and another unidentified board.

it appears that the company was semi-legit, since I found references to a bunch of biomedical applications that used that stepper board, for instance.

Anyone have a data sheet or know of where one might be found for the boards?

I don't even know what system they went with, the estate sale was full of every sort of odd stuff, more than I could haul even if I wanted to...... Solar stuff, ham radio, and electronic 'gizmos" of every description.

The board were actually in with a bunch of current transformers, which was what I was actually after. But I do have a use for a stepper driver, if I can get some specs either "official", or derived from tracing it out.

I could, if motivated, trace these boards out, but that would be a back-burner job. It would clearly be simpler if there really was a data sheet somewhere.

Google only got about 8 hits on the specific stepper driver board, lots more on plain "Alpha products", but tons were golf-related, obviously some other company.

Thanks in advance.

Evan
05-19-2008, 03:10 AM
The board almost certainly uses the ST Microelectronics L297 stepper controller and L298 driver ICs. Here is an application note on those products.

http://www.st.com/stonline/books/ascii/docs/1679.htm

J Tiers
05-19-2008, 09:19 AM
ST L6221A darlington array, with some logic around it, actually.

It seems to be fairly primitive, but might be useful to save the trouble of doing wiring.

If anyone had a data sheet for the assembly it would be much easier to determine how much work it would be to use it, and whether it would do the needed job.

Evan
05-19-2008, 10:16 AM
Data sheet for the part:

http://www.st.com/stonline/products/literature/ds/1379.pdf


That would be just the output circuit. There is probably the controller I mentioned on there too as the L297 was one of the most commonly used parts in that sort of equipment during that time frame. It's a very basic stepper driver.

lwalker
05-19-2008, 12:22 PM
Holy canoli, Batman!! There's a name from the past!!!

Alpha was my first job out of college. It was a tiny data acquisition/control equiment manufacturer and went belly up (finally!!!) in 1996 or so which was when I was laid off.

I think I designed the DA147 -- it's been so long I don't remember exactly, but it's a very simple four channel 12-bit Digital to Analog converter. The ST143 is just a ULN2803A with some decoding logic; you have to do the stepping in software. Do you have an SC149? That's a "real" stepper controller with a Z80 microprocessor. Does the "unidentified board" have a chrome bracket and an ISA card edge? If so, it's almost certainly an AR133 interface to a PC bus. The Alpha Products ABUS was a proprietary bus that interfaced to a number of computers available in the late 80's - early 90's.

PM me if you want more specifics. I can probably get you up and running if you have all the right parts.
Man, you just sent me down memory lane :-)



In with a bunch of other stuff I got recently were some boards from a company "Alpha Products"..... A "DA-147" D-A, an "ST-143" stepper driver, and another unidentified board.

it appears that the company was semi-legit, since I found references to a bunch of biomedical applications that used that stepper board, for instance.

Anyone have a data sheet or know of where one might be found for the boards?

I don't even know what system they went with, the estate sale was full of every sort of odd stuff, more than I could haul even if I wanted to...... Solar stuff, ham radio, and electronic 'gizmos" of every description.

The board were actually in with a bunch of current transformers, which was what I was actually after. But I do have a use for a stepper driver, if I can get some specs either "official", or derived from tracing it out.

I could, if motivated, trace these boards out, but that would be a back-burner job. It would clearly be simpler if there really was a data sheet somewhere.

Google only got about 8 hits on the specific stepper driver board, lots more on plain "Alpha products", but tons were golf-related, obviously some other company.

Thanks in advance.

J Tiers
05-19-2008, 11:13 PM
lwalker knows...........!

yeah, it's a bare-bones driver, really better called an "interface", most likely.

No Z-80, no L297, nothing at all like that.

The 3rd board is an MX-155, whatever that is.

Sounds like, as I suspected, the stepper driver is basically not very useful...

The D-A maybe, and the 3rd depends on what it is....

There are so many configuration plugs that it becomes troublesome to see how each was intended to be used.......

The mug shots:

http://img.photobucket.com/albums/0803/jstanley/alpha1.jpg

http://img.photobucket.com/albums/0803/jstanley/alpha2.jpg

Evan
05-19-2008, 11:46 PM
It's hard to tell without knowing the hookup but that bottom board looks more like a servo driver rather than a stepper driver. The 74LS502 is a successive approximation A to D converter, the LS139 is a decoder and the 273 is an 8 bit latch.

lwalker
05-20-2008, 12:39 AM
The MX155 is a multiplexer for the Alpha single channel 12bit A/D card it gave 32 single ended or 16 differential inputs depending on the configuration.
The pots on the DA147 are for trimming the reference on each channel.

Each board can be placed anywhere in a range of 64 addresses by moving the jumpers in the sockets. When I started to design for Alpha (as opposed to being a junior flunky :-) I switched from DIP sockets and jumpers to DIL headers and shunts since they were much more reliable and cost about the same.

Without an adapter those boards are useless. If you look at the card edge connector you'll see that they all use an identical 25-pin bus (later boards will have gold flash, older ones are tin plated). That's the ABUS -- it's essentially a simplified version of the ISA bus and we made adapters to connect between it and a PC, Apple II, serial, TRS80, and even had an ABus 8052-based Single Board computer running BASIC-52.
So there would be an adapter that plugged into your computer, then a 25-pin ribbon cable to an individual board, or to a backplane that these boards would plug into. Power comes through the 3.5mm jack near the edge connector or pins 1,2, 4 & 25 on the edge.
It was a bare bones design that brought the cost down dramatically from the competition (National Instruments, Data Translation, etc) and we sold TONS of them. John Monin (the owner) made a mint on the ABus.

Wish I could help more, but I tossed all my old Alpha stuff years ago! Can't believe I actually remember any of this :-)

--Lyndon

J Tiers
05-20-2008, 09:09 AM
It's hard to tell without knowing the hookup but that bottom board looks more like a servo driver rather than a stepper driver. The 74LS502 is a successive approximation A to D converter, the LS139 is a decoder and the 273 is an 8 bit latch.

Evan:
You have probably by now noticed that it is a 74LS02....... not a '502. And the 139 is actually a different number also. Hard to read in the pic.



lwalker:
They aren't entirely useless, since I am yet another one of the electronics engineers who seem to be prevalent in the home shop crowd...... but it is a question of the effort required vs some other more direct approach.

As far as I know, there wasn't any ABUS adapter at the sale where these came from. Very possibly it was in or with the (rather older) computer that was there. The guy had been a real tinkerer.... there was a solar panel setup, a Kato motor-generator setup for 3 phase, some 3 phase transformers, lots of battery chargers, ham radio equipment (much of it home-made), Heathkit (ancient) and all kinds of miscellaneous parts, "stuff" and literature, including a copy of the K N Harris boiler book. I nabbed the boiler book, already had the engine book.

They wanted WAY too much for the big stuff, and it is probably all in the dumpster now...... stupid

What I was actually after was the bag of 15 100A current transformers..... these boards were inexplicably in with those.....

Evan
05-20-2008, 11:05 AM
Evan:
You have probably by now noticed that it is a 74LS02....... not a '502. And the 139 is actually a different number also. Hard to read in the pic.

http://vts.bc.ca/pics/eye.jpg

So it is. Time for new glasses. :rolleyes: