Books on logic design using relays and timers? 6

[antenna2001]

I have been unsuccessful in finding any books that describe the process of designing motor control ladder logic. I took several Digital Logic Design classes. Neither one included logic using the variety of contacts and timers available. Rather than reinventing the wheel, I'd like to read a book to get me started.

Thanks

 

[itsmoked]

I have never heard of "motor control ladder logic".

Me thinks you are looking for the golden goose...


What EXACTLY are you looking to do/control/motor? So we might be able to help you further?

 

[Skogsgurra]

Yes, there are such things. All relay control diagrams look like ladders after about 1940-50. That's when most people abandoned the "landscape paintings" showing each and every contactor almost as a nature morte and how the wires were connected. Beautiful but not very practical. As soon as there was more than a simple on/off plus thermal these drawings became impossible.

Try Moeller. They used to have relay diagrams for common tasks like star/delta starters, Dahlander control, rotor control for hoisting devices and so on. Siemens has a book called "Schalten, Schützen, Verteilen in Niederspannungsnetzen". I know that it exists in English also - probably named "Switching, Protecting and Distribution in low voltage grids" or similar. It has lots of the stuff you are looking for - only that European ladders are horisontal, not vertical.

Gunnar Englund

http://www.gke.org

 

[itsmoked]

Horizontal !!! That's not a ladder!!! It should then be called a scaffolding diagram.

So he's just talking about ladder logic that happens to have some motors involved? Strangely put.

 

[jraef]

Am I the only one ammused by the fact that books on relay ladder logic have apparently become a rare commodity?

Ohhhh... do I feel old now!

Eng-Tips: Help for your job, not for your homework Read faq731-376

 

[Skogsgurra]

..or a fence...

Gunnar Englund

http://www.gke.org

 

[alehman]

I hear you, jraef. The only books I've seen that discuss ladder logic are tutorials for PLC programming (which is still frequently represented in the ladder format).

 

[antenna2001]

itsmoked: Traditionally, motor control logic is shown in terms of ladder diagrams. I know how to design using digital logic gates such as AND, OR, J-K flip-flops, and the like. My problem now is that I am trying to design circuits that perform the same function as logic gates using contacts, control timers, control relays, motor starters, and all the other functions that are used in ladder logic. This generates several design problems that require a different, systematic methodology that is not available in the classic digital design. There must be books out there that describe the process in detail but I have not found them yet.
Sorry I did not explain myself well the first time and thanks for the replies.
Antenna2001

 

[swgrmfg]

Mr. Antenna2001:

You might want to consider investing in a micro PLC for a couple of hundred dollars, and a few toggle switches and control relays and program your circuits from your digital logic in the PLC. Some PLCs actually talk boolean. This way you can simulate your circuits, test them, and then hard wire them according to your ladder diagram (avoid using Fancy Functions). You'll learn more hands-on than you would with a book. Books cannot show you where race circuits, feedbacks, infinite loops, and other real life physical traps in relay logic are.

I know somebody who did just that!

 

[resqcapt19]

Take a look at a software program called the " the constructor". It lets you build and test run "ladder logic" circuit on your computer.

http://www.cmhsoftware.com/

Don

 

[waross]

No jraef, you're not the only one.
I remember learning "And"s "Or's, "Not"s etc. "GE Solid State Plug in Logic Modules", and hard wiring Boolean logic.
All with a ladder logic background.
I learned ladder logic mostly by using existing drawings. Some of my texts had a chapter on Ladder Logic, but I don't remember a text devoted soley to ladder logic. I had a couple of texts devoted to Boolean logic. Whenever I saw a usefull convention on another's drawing I would add it to my personal preferrences.

 

[tommom]

Try searching bookfinder for: Electric Motor Control Fundamentals by R.L. McIntyre, published by McGraw Hill.

 

[moggie]

Have a look at the Moeller Electic Wiring Manual.

It includes sample cirucits for all types of motor control, including Multi-speed contactors/star-delta contactors/DOL contactors/Automated pump control.
It shows the motor wiring as well as the control wiring.

 

[mc5w]

The University of Akron in Akron, Ohio has a book on relay logic and it is not any different than TTL or any other logic form as far as analysis goes. As far as fanouts ( how many contacts a coil can run and how many coils a contact can run ) is slightly different. Usually, you have to check if a normally closed contact has a lower rating than normally open for a given relay if if both kind of contacts have the same rating.

I can understand how some computer logic teachers may pooh pooh wanting to do relay designs, but the logic approach should be the same.

Oh, asynchronous logic at first may seem to be harder than synchronous digital logic but the clock in synchronous logic merely quantizes time. You still have the same opportunities for race conditions and so forth.

After I had figured why the parts bin washer at 1 place had not worked for 20 years in automatic mode because a hole for a limit rod had been misdrilled, someone asked me if sticking in a programmable controller would have helped. I told him that they still would have had a case of Garbage In Garbage Out.

 

[Electromechanical30]

Try looking for a text book called Industrial Motor Control on Amazon. I think that it will suit your needs.

 

[BJC]

antenna2001
Here's agood book on relay logic and it includes a chapter on relay logic. The book was published aut 30 years ago by Westinghouse. There is also a chapter on The Westinghouse "Cypak" logic modules. They were plug-in modules that included "and", "nor" "or" gates etc. They only thing you could do before LCs.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7588397692&category=66943

 

[panelman]

Telemec do a freebie called “principles of motor control” that covers the basics and most forms of starters. It is aimed at the European market so fences rather than ladders

 

[waross]

This link may be worth looking at.

http://www.newstandardinstitute.com/outline_CT2030.cfm

yours