Domestic electronic controller 5

[gearhead333437]

Greetings Friends,
I am a mechie but have only a glancing involvement with electronics.
have a water softner which has a small processor. The resin regeneration process consists of a small motor which rotates a plastic cam shaft which, in one rotation, opens and closes various valves. The regenerating "cycle" is meter initiated,
Basically a 3/4 inch plastic "turbine" is living in the water outlet and a magnetic pick-up cable runs to the processor
and the small motor is started. I see the motor is stopped after one rotation by a micro switch. My question is how the
meter is starting the motor. Any help will be much appreciated. Thanks for reading.

 

[crshears]

Service personnel or homeowner sets water hardness level in memory, based on results of water analysis, also present time of day, desired regeneration start time, etc., etc.

Processor counts number of pulses from magnetic pickup & compares same against number stored in memory; number stored in memory varies inversely as the hardness of the water.

Once number of pulses has exceeded number stored in memory regeneration cyle will be initiated during the next overnight period when water usage should be zero to minimal; there is typically enough service margin remaining for the softener to last the balance of that day so its zeolite is not compeletly exhausted by regeneneration time.

More than likely the micro switch will be operated by a series of index notches on the periphery of the nylon cam wheel to bring it to rest one step at a time as regeneration proceeds.

Timing and duration of backwash / brine tank fill / regeneration / fast rinse / back in service is governed by processor programming.

Particulars of how processor initiates drive motor start will depend on manufacturer & unit design.

Hope this helps.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[waross]

Basically the controller jumpers or bypasses the micro switch until the motor has rotated the cam far enough that the micro switch recloses. Then the controlled circuit opens and the cam is able to stop the motor at the correct position.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[gearhead333437]

Good stuff thanks for your in put CR and Bill, Nice little unit (Autotrol,Series255/460i)
From my observations the motor once bypassed (thanks Bill) does not stop again until the disc has made one rotation, about
two hours, when the pin on the disc contacts the micro switch.The profiles of the seven cams (on a common shaft) are designed such that the cam's lobe will be in contact with a valve disc for a specific duration to accomplish a particular task such as
backwash, regeneration, fast rinse etc. I was curious to know which part on the processor is starting the motor. As of now the
unit operates normally when a manual button is pressed however, will not go into regeneration automatically via the tubine "meter" countdown as it always did. when I called at Tech at autotrol he seemed to mention the word "polarizer" phone connection was bad. Seem to remember a Totalizer Chip from an old project.Does this make sence that as CR said some preprogrammed value is met and that a by-pass is initiated and at 2A.M. the motor is allowed to run that one revolution?

 

[MikeHalloran]

I claim no specific knowledge of softener controls.

Symptoms reported so far suggest that a wire or printed circuit trace has cracked or corroded, or more likely, the turbine has become fouled or unbalanced, and no longer rotates freely.



Mike Halloran
Pembroke Pines, FL, USA

 

[gearhead333437]

Thanks for responding Mike, As far as why the unit failed in auto the answer may by your first
suggestion. As for the Turbine I tested it first by waving a magnet past the pick-up to test the cable and the led flashed to indicate flow. later while I had the unit in manual regeneration I opened some faucets and again the led flashed. so it seams that the pick-up/cable and the turbine are operating as they should?

 

[waross]

Take a look at the instruction and trouble shooting manual.

http://ilovemywater.com/uploads/manuals/manual144.pdf

Items 5 and 10 on pages 19 and 20 sould be helpful.

Every day, at 2:00 a.m., the past seven days’ water
usage is statistically averaged to anticipate the amount
of water that will be used the next day. The computer
then determines if the water conditioner has enough
remaining capacity to supply the next day’s needs. If
not, the unit will regenerate.

You may not be using enough water, and you may not be waiting for 2:00 A.M.
Also the turbine may be dirty and running slow.
Slowly open a valve to use water and see if the indicater rate increases with increased flow.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[gearhead333437]

Thanks again for your efforts Bill,
I will download the manual as you suggested, and definitely check the indicater rate.
All the Best; Joe V. Montgomery, N.Y.

 

[crshears]

One continuous run of ~2 hours? Definitely a different design than I'm used to; all the units I've ever worked on had a little drive motor that ran for several seconds at a time as directed by the process controller to step the plate valve through its sequences. Oh, the many ways that the same task can be accomplished...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[gearhead333437]

yea, CR that was my experience as well. That it why I thought it might be a fun but also a learning item to share.
even though it is only a household water softner the ideas can apply to anything. I myself have been around both the design and build and repair of systems for many years however, I learn something almost every day. I am sure this applies to most of us here. Later

 

[waross]

One continuous run of ~2 hours? Definitely a different design than I'm used to; all the units I've ever worked on had a little drive motor that ran for several seconds at a time as directed by the process controller to step the plate valve through its sequences.

The continous run sounds like washing machine technology. For a process that is able to use timed steps, a small motor geared down to one turn every 2 hours has some advantages. Yes, I know that in a wshing machine the timer and switches activate valves and solenoids but the principle is the same as having a cam acting directly on the valves. And, by the way, there was a model of washing machine on the market years ago that dispensed with the solenoids and had the timer driving cams that controlled the cycles directly. The timer may also turn itself off and wait for input from a device indicating that a cyle has completed to restart the timer motor to move to the next cycle.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[gearhead333437]

Wow, nice ideas! funny that you mentioned the washing machine cycling that is exactly what i thought of when I started with this Controller. The motor is, 3 phase. 349 h.p. (just kidding), 12volt and 6watt but I forgot to get it's actual rpm when I had it apart but the gear train gets us a 1/2 rph (.008 rpm) as you noted. Each of the seven flapper valves are operated by the force of its respective cam. ALL the pressure that allows for flow is got from the 50 psi at the water inlet. Totally mechanical except for the 12 volts for the 6 watt motor and the processer. Indeed in the event of a power outage, if your crazy enough, and I am, I could operate this thing by pushing on the flapper valves for the necessary time for each cycle.
Booklet recommends about 82 mins for a manual cycle
Backwash-14 min.
Brine/slow rinse-52 min.
Brine Refill-10 min.
Fast Rinse/Refill-6 min.
all that is needed is water pressure on the system!!!

 

[jraef]

I know nothing of these systems in particular, but the "turbine" description sounds like a turbine flow meter, so Bill's theory on insufficient flow makes a lot of sense. If you know for sure the flow isn't actually insufficient, then because the flowmeter is sending pulses or waves to a totalizer, it might be a loss of that totalizer value that makes the mP "think" the flow is insufficient. The first and easiest check to make is to follow that wire from the magnetic pickup and make sure that wherever it connects, there is not a build-up of corrosion or something obvious like that. Those sensors work on very very low signal energy, even the slightest increase in circuit resistance can render them useless.

"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[gearhead333437]

Thanks for sharing jraef, I did catch Bill's comment on turbines and did follow-up. The blinking of the led flow indicator
did vary with the flow. I checked at low, medium, and higher, flow and the led varied accordingly and our normal water usage has not changed. I also removed the magetic pick-up to check/clean and all was free of any corrosion. All insightful input but as a very smart mentor told me many years ago, "there is always the 16 ounce ball peen hammer" ha ha, just kidding, so was he! Joe

 

[waross]

Grin. Your mentor must have been from the same school as mine;
"Nothing we can't fix with a big hammer and a sense of humour!"
Checck the limit switch that signals the end of the cycle.
If that has failed your proccesor may think that it is in a cycle.
The device works on manual, so it may be a high resistance rather than a complete failure.
The proccesor may have failed. Most likely failure may be the output circuit.
Check that the jumper is on the top set of pins (TIME).
Check that the jumper is not dirty or corroded.
Check that the hardness and capacity settings are correct.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

Yes the guy on the phone said "Totalizer" which is what the processor does, adding up the total consumption. As suspected it then runs the motor/cam system in a timed sequence as a "drum controller" a classic mechanical control system used in many applications such as wash machines and water filters.

The processor board has likely had a failure on it which would include in order of likelihood:
1) Bad corroded wire connection
2) Bad corroded board trace/component connection
3) Failed power supply due to capacitor age-out resulting in instability and possibly an AC component in the supposedly DC supply which trips up the processor.
4) Failed power supply dead.
5) Dead as doornail processor due to a power spike from lightning or some other major power disturbance.
5) Aged-out processor code memory. 10 years is pushing it on most 'programmed' processors.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[gearhead333437]

could not agree more Bill those old school mentors were the best.
The limit switch is a normally closed switch it is only opened as a pin on the cam wheel makes one rotation and contacts it.
In auto it must bypass the open circuit and in manual pressing a button moves the pin past the switch's actuator arm.
If not for this switch the motor would run all the time. In manual the switch seems to work fine. The jumper is on the top pin set. nothing is corroded and the settings are as the manufacturer suggests. I will probably buy a new mP (timer) but because that same mentor condemned the phrase "its broken" I wanted to know what failed. As I said electronics is a weak suit for me so I don't know the sequence here. Basically I am thinking of the turbine pick-up as a transducer which senses the movement of the turbine and gives an electrical signal to some sort of "relay" which allows the limit switch to be closed
so that the cam motor will turn. Sorry for all the words, Joe

 

[gearhead333437]

Thanks for your input Keith, the thing was made in 04, I am in a rural area and we have had our share of outages etc.