# Control Circuit Prototyping With Ulma Doctor!!!



## Ulma Doctor (Dec 12, 2014)

Hey control circuit fans,
i 'm faced with a meldown on a piece of processing equipment.
the control systems are less than reliable so i came up with my own system to replace the painfully inefficient OEM system.
my system is heavier duty in the finished work.
 this is merely a representation of how the circuit will end up working.
it will end up controlling a 7.5 hp 3 phase 230 v motor and a 1 hp 3 phase 230 v motor simultaneously or just the 1 hp motor by itself.
if you are interested and wanna take a peek click the link below.

[video=youtube_share;_J_9iO0RgtM]http://youtu.be/_J_9iO0RgtM[/video]

thank you for watching
please feel free to question and comment
mike)


----------



## Micke S (Dec 13, 2014)

Interesting, what type of prototype development kit are you using?


----------



## Ulma Doctor (Dec 13, 2014)

the console showed in the video is a Radio Shack electronics learning center.
i purchased it many years ago when i needed to create a circuit for an old meat processing machine electronic board.
the manufacturer long since has been out of business and the board was no longer available form normal sources.
i recreated the function of the board with a lot less components.
i increased the ratings for all the relays, capacitors,switches, rectifier bridge, and the machines entire control circuit.
the machine is still in service 5 days a week M-F, it's been 6 years now.
the Radio Shack center was cheap and it even came with some books and a small array of components.

thank you for reading Micke S!!!
)


----------



## vettebob (Dec 13, 2014)

Are you using those relays to control your contactors or are you running the motor with those? Motors should be used with contactors and overheat coils whenever possible.  Bob


----------



## Ulma Doctor (Dec 13, 2014)

Hi Bob,
thank you.)
this is not my first rodeo !!!
i bring dead and broken machinery back to life for a living !!!

the relays in the video are not the relays that will be used in the retrofit.
i merely used the relays for a model for testing the control circuit.
the LED's are markers for intended current flow.
none of these relays will be used in the final control circuit. 
in my control system there will be a 3 HP 3 phase rated Contactor with OL relay, a 15 hp 3 phase rated Contactor and OL relay, 10A 600 V rated momentary switches, a 200VA step down transformer, Proximity Sensor Safety switch.
the control circuit in the video was much simpler by omitting the OL's, transformer , and safety switches.
these items will be introduced into the retrofit as it's being installed. )

i'll be sure to post pictures of the installed retrofit for the interested.


----------



## vettebob (Dec 13, 2014)

Sounds good; was just checking. I'm a retired Substation and Powerplant  Electrician as well as Aircraft A&P.  Bob


----------



## Ulma Doctor (Dec 13, 2014)

thank you Bob for covering my 6 o'clock!!!!:thumbsup2:


----------



## Wireaddict (Dec 14, 2014)

Since you're just verifying the logic here & seem to know the rules you shouldn't have any problems.  Enjoy!


----------



## Karl_T (Dec 14, 2014)

Ulma Doctor, we have similar backgrounds. Glad to know another controls guy likes to mangle metal for fun.

Karl


----------



## Ulma Doctor (Dec 15, 2014)

Thanks Karl, i just love messin' with machines and metal.
just don't ask me anything about carpentry, wood splits and crumbles at the very sight of me!!!:jester:


----------



## Ulma Doctor (Dec 15, 2014)

For those interested,
 i was not able to take a picture of my completed work.
the processing facility did not want me to take any photographs inside their building.
 i had to respect their protocol if i wish to continue doing business with them.

in the near future i'll make and post a wiring diagram so that others may gain a little insight into how momentary pushbutton control systems operate.

the system worked exactly as designed.
 another successful retrofit !!!


----------



## Karl_T (Dec 16, 2014)

Ulma Doctor said:


> Thanks Karl, i just love messin' with machines and metal.
> just don't ask me anything about carpentry, wood splits and crumbles at the very sight of me!!!:jester:



I'm EXACTLY the same way with home repair and improvement carpentry. Hire that out so I can spend more time making a machine do my bidding. My love is taking a pile o' scrap and turning into something that does work or play for me. That can be anything from an automatic soda can crusher, to a CNC milling machine, a rebuilt firearm, a part for farm equipment, an apple packing line improvement, on and on. 

Karl


----------



## Ulma Doctor (Dec 16, 2014)

Thanks Karl,
i think we were cut from the same cloth!


----------



## Ulma Doctor (Dec 16, 2014)

I haven't made the diagram yet.
i was able to take pictures of the components and wiring that i removed from the deceased machine.
it's way too complicated of a system for what it's doing.
Manufacturers constantly try to baffle technicians with 12 control steps when only 3 are really necessary.
it's my opinion that engineers should have to work on their creations in real world scenarios before they can create other things. 
the engineer's design would drastically change, if he had to fix what he made. that i guarantee .

there was extensive water damage to the control system. a couple pictures from the corpse.




the picture above was the old, unreliable control system less a transformer a bridge rectifier, proximity sensor safety switch and momentary control switches.

the picture below is the control wiring i removed to install my retrofit.
my control circuit is simpler and the components are twice the ratings they have to be.
good is just not good enough, make it the best you can!!!




the retrofitted machine will see operation 7 days a week for at least the next 5 years.

i'll post diagrams upon completion.
thanks for reading


----------



## JimDawson (Dec 17, 2014)

I love to simplify stuff like that.  Most time there is no reason to make something complex when simple will do the same job.  The less parts there are, the less chance of a failure, and if there is a failure, it's easier to troubleshoot.  Nice job!


----------



## Ulma Doctor (Dec 17, 2014)

Thank you very much Jim, i agree 100%!!!

I never understood the mindset of making things any more difficult than it has to be.
I'm always in the process to simplify whenever possible.
that's basically my job in a nutshell- 
here's my formula for success
identify problems, simplify the issues to lowest common denominators , correct problems, collect paycheck, & repeat

mike)


----------



## Ulma Doctor (Dec 20, 2014)

i finally finished the wiring diagram for the control system retrofit.

the first picture is a scan of the diagram that i did for the retrofit when the idea first popped into my head.
i laid it down quickly but it got the general idea of how i was going to wire it up.
this was the actual diagram i used. i did make a couple wiring changes to accommodate the overload wiring.
the general concept was retained as drawn(crudely).
 beware it's not pretty:lmao:
i know it looks like my 4 yr old son drew it up, but i assure you that was my crayon and marker work:jester:



i cleaned up the very crude and rough sketch.
it produced another rough and crudely animated computer generated version that may be a little easier for others to follow!



I welcome questions, comments, and criticisms.

as always, thank you for reading.


----------



## Karl_T (Dec 20, 2014)

The second drawing was a waste of time. Mine always look like the first one :rofl:

I assume the two NO and one NC contacts are reset and Estop, or start and stop,  pushbuttons.

Karl

PS, while certainly a robust and elegant solution here. My first thought would have been a small PLC, especially if I seen 24 volt coils on the existing motor starters.


----------



## Ulma Doctor (Dec 20, 2014)

Karl_T said:


> The second drawing was a waste of time. Mine always look like the first one :rofl:
> 
> I assume the two NO and one NC contacts are reset and Estop, or start and stop,  pushbuttons.
> 
> ...




Thanks Karl!
the momentary switches are 2 start buttons 1 stop button.

I'd love to put a PLC in the control box.  
 unfortunately the environment is extremely harsh where the machine does it's duty.
 i could not put faith in a PLC system for durability for this particular job .
 not that a PLC can't be reliable, i just don't trust them in an absolute time of need.
 the job is kinda far away so i tend to make things way better than they have to be.
i don't like to do the same job twice if i can avoid it!!!


----------



## Karl_T (Dec 20, 2014)

Makes sense.

In my job I was always faced with creeping elegance.  "Now that you fixed that, can you make it do this too?"

Karl


----------



## JimDawson (Dec 20, 2014)

I like the first drawing the best, that what most of mine look like.  )


----------



## Ebel440 (Dec 20, 2014)

I have to agree with you that engineers should have to have some time with whatever they are designing. I don't mean it as anything against them but it seems to me they sometimes design things with no idea how things are actually made. I had a few friends in school for engineering and they had no idea what milling machines etc were or what they did.  Seems to me if your going to design something you should know how it's going to be made.


----------



## brav65 (Dec 20, 2014)

Ulma Doctor said:


> I haven't made the diagram yet.
> i was able to take pictures of the components and wiring that i removed from the deceased machine.
> it's way too complicated of a system for what it's doing.
> Manufacturers constantly try to baffle technicians with 12 control steps when only 3 are really necessary.
> ...



Well I am a wood guy and metal rusts when it sees me, but I am attempting to join the ranks of you metal guys.  On the wood side we have the same problem with engineers.  I was once given an engineered repair for a broken truss that called for a 2"x4"x48" patch to a truss cord with two rows of 16d nails (3 1/2" long and 10 gauge) 2" on center.  If completed as designed there would have been no wood left only nails.  When I called the engineer to suggest an alternate he was dumbfounded and told me he ran the numbers again and it calced perfectly.  I put two rows of nails in a 2x4 (taped it back together with duct tape) and sent it to his office.  I got an e-mail the next day with an alternate design for the repair, with no comment from the engineer.  

Great work, and thanks for sharing.  I am getting the parts together to create a DRO controller using Yuri's design and iGaging scales.  I have absolutely no idea what I am doing, but figured I need to challenge myself to learn new things!


----------



## John Hasler (Dec 20, 2014)

Ebel440 said:


> I have to agree with you that engineers should have to have some time with whatever they are designing.



That's what we often say about the managers who tell us what to design.


----------



## Ulma Doctor (Dec 20, 2014)

Karl_T said:


> In my job I was always faced with creeping elegance.  "Now that you fixed that, can you make it do this too?"
> 
> Karl



:lmao:
that quoted phrase is the story of my life.....

i especially love it when they asked me to put a 10 hp motor on a machine that came with 5 hp motor.
i had a guy tell me straight faced that a 1725 rpm 10 hp motor will turn his machine faster than a 5 hp 1725 rpm motor.
:banghead:


----------

