Discussion in 'Circuits' started by Admin, Apr 17, 2013.
This thread is for the discussion of the Stepper Motor Controller circuit.
This circuit NOT working!!!
Show us your breadboard creation and we can help you more.
Make sure you have the right wires going to the proper pin-outs on your transistors and the 78L05
Just look at circuit. Supply on 1 pin, ground on 8 pin...
The bottom of the diagram may not always mean ground. Look at the 100n capacitor, It's going to ground at the top of the diagram.
And 5v going to pin number 1
something wrong in diagram, it cant working
Not the best of schematics. A starting point would be to look at and fully understand the internals of the 555. This is covered elsewhere in (learning) and should enable you to decide exactly what goes where and more importantly WHY! Good luck.
How can I modify this circuit to run a 3 phase stepper motor that runs with 28VDC?
You can't. A 3 phase stepper would require completely different control circuitry.
I'd love to hear if anyone has ever made this circuit work. On paper it makes almost no sense. The power and the ground are hooked up backwards, and it would rely on pins that aren't outputs to signal the transistors. My only guess is that it relies on a bi-polar stepper motor and somehow the circuit might work if the impedance of the coils somehow signals the inputs to swap.
If anyone has ever made this work, please post and tell us if it worked as drawn, or what modifications were required to make it work. Also, post how the stepper coils were hooked up.
It should be obvious to everyone that this is a bogus circuit, if you think that these components could possibly hook up to a 555 this way. It makes absolutely no sense. That is because this is not a 555 timer, it is a failed MCU prototype TE555-1 , actually a modification of an old PIC controller programmed as a bipolar stepper motor driver that never made it to prime time. The 78L05 should have been the first clue... This phantom "MCU" has totally different pin outs, but besides that point, it is no longer available, if it really existed at all.
Here is the datasheet for the LM78XX Series chip http://pdf1.alldatasheet.com/datasheet-pdf/view/9047/NSC/78L05.html
As far as no longer availible it comes in 3 types, TO-92, SO-8, and 8-Bump micro SMD. http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_51182_-1
I have never made this circuit but with just a couple seconds of searching I do see the chip/Voltage Regulator are availible. There are many parts that are obsolete and very easy to get, I sell electronic components and about 90% are obsolete (NOS).
The discussion is not about a 3 pin regulator (78L05), that is a common part. It is about the 8-pin TE555-1 that people in this forum were confusing with a 555 timer. There are so many problems with the circuit shown when viewing as a 555, and the first clue, before even looking at the rest of the circuit was a 78L05 connected to a 555 in this way.... bogus. That, however is a common component used with some PIC processors, and that is the instant givaway that the chip shown is a PIC configured as a bipolar stepper motor controller, which is bogus as well, because it does not exist today, or perhaps never did.
BTW: If you build this circuit using a 555, all you have done is made a rather expensive firecracker.
If this is an invalid circuit or at least one that is not using the 555 timer or a part that doesn't exist, why is it even on this page?
Except you can buy the 78L05 here so I don't know what you're talking about. Also, this datasheet confirms the pin outs. You're right about the TE555-1 though.
The 78L05 can be bought much cheaper than Digikey at my store for $7.00 per 100Pcs
Or that too, I was just giving reference that the product is still available and not out of service. I do recommend buying from George as he gives some good deals on his products.
Could you go deeper into detail? Anyone could just say, "No, this wont work." So I would like if you explained why it won't work. I'm not much of an expert in these kind of electronics but I won't believe somebody on the internet who says, "It just won't work," if they can't tell me or reference something to me. I mean, your first post on here was simply saying how bogus this circuit was, but I already debunked half of your statements with proof. If anyone can tell me why a 555 wouldn't work, that'd be nice.
LOL I just thought I could throw a little advertisement in here.
The reason they are saying it won't work is because of the specific 555 timer listed. I have had trouble finding it as well but this plan is on other sites as well so I don't know for sure if the doubter is correct or not.
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