Timer Relays and Valves

Discussion in 'The Projects Forum' started by Crazywizard, Jan 21, 2015.

  1. Crazywizard

    Thread Starter New Member

    Jan 21, 2015
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    Hello,
    As I age I just cannot work things out like I used to so please help me if you can.

    I have 2 x 12 volt 3 way valves that have 2 wires each. To operate each way requires the power to be reversed - same as you would to forward and reverse a motor to run in either direction. These valves cannot be energized all the time as that would burn them out and they only need 5 second run time to turn either way by having their wires reversed.
    Both valves are to operate at the same time.
    I have 2 x timer relays (SPDT) that are set to 5 seconds so when power is supplied to the coil the relay will switch on for 5 seconds and then automatically switch off.
    My plan is to use one timer relay to turn the valves one way and the other timer to reverse the wires and turn the valves back again.
    I need a diagram of how to wire this please as my brain isn't doing a good job of working it out.
    I think the fact that the valves can only receive power for 5 seconds is confusing the issue.
    By the way, I do have other regular relays available to use also if needed.
    Please help sort this out for me, your help would be greatly appreciated.
    Many Thanks,
    Les
     
  2. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi,
    If I read you correctly.?
    Timer1 would drive both Valves forward for 5 seconds.
    Timer2 would energise a secondary relay for 5 seconds that would reverse connect the two valves to power.

    How are the Timers initially powered to Start timing.? Is it a manual push button, timed interval switch,, etc.???

    E
     
  3. Ramussons

    Active Member

    May 3, 2013
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    The simplest way is as shown in Fig 1.
    I would use Fig 2. It ensures that the power supply is not shorted by a Relay Malfunction.

    Relay 1.jpg
     
  4. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    But don't these circuits require DPDT relays? The TS specified he had SPDT timer relays plus unspecified others. If those other relays include DPDT 5 second timer relays, good. Otherwise it's purchase time.

    And we still don't know how he is triggering the relays.
     
  5. Crazywizard

    Thread Starter New Member

    Jan 21, 2015
    11
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    Forgot that part. The trigger is a thermostat so it acts as an automatic on off switch. So I may need to use the 5 second output to trigger one or more DPDT relays to do the job?
     
  6. Crazywizard

    Thread Starter New Member

    Jan 21, 2015
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    Also the timer relay has a white "trigger" wire so the coil could be connect to pos and neg all the time and every time the white wire is supplied with power - can only to be for a millisecond - the relay will reset and go through the 5 second countdown again. These timer relay can be used for many purposes and set to be a delay timer as well.
     
  7. Reloadron

    Active Member

    Jan 15, 2015
    963
    232
    Hi Les,

    OK, I am a little curious. It sounds like you have 3 way magnetic latching valves that use a single coil, some use a single and some use two coils. Valves like this are generally actuated using a pulse to the coil but the pulse duration is normally well below even one second. Another type of 3 way valve can be the motor driven type where a small motor runs one way to open the valve then with reverse polarity runs the opposite direction to close the valve. Would there be any way you could post the valve manufacturer and part number? Even a link to the valve data sheet? I am just curious.

    Ron
     
  8. Crazywizard

    Thread Starter New Member

    Jan 21, 2015
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  9. Reloadron

    Active Member

    Jan 15, 2015
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    OK, I get it, they are actually motorized ball valves. Pretty cool and I see how you want to use them with a thermostat. The timers you have are pretty cool also. The timers offer several modes of operation. What you want to be able to do is trigger the timer as a one shot with a 5 second duration and control the polarity to the ball valve to open or close depending on temperature. Let me give this some thought. I should have an idea or two by tomorrow as how to configure things. There is some neat stuff pouring off the boat from China. Unfortunately much of it lacks good documentation (data sheets). :)

    Ron
     
  10. strantor

    AAC Fanatic!

    Oct 3, 2010
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    Here's how you can do it with your two SPDT timer relays, no need for DPDT timers, no need for additional interposing relays.
    2spdt.png

    Also shares ramusson's protection from relay malfunction.

    EDIT: it was implied the two motors would be in parallel. Not sure if I need to show that, but here it is, just in case:
    2spdt.png
     
    Last edited: Jan 21, 2015
  11. Crazywizard

    Thread Starter New Member

    Jan 21, 2015
    11
    1
    Unfortunately that does not appear to reverse the polarity, or am I missing something? By the way, the valves that I have are the 5 wire CR-05.
     
  12. Reloadron

    Active Member

    Jan 15, 2015
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    Apparently the valves come in a few flavors. The part number has the suffix CR1, Cr2 or CR5. You are showing the CR5 configuration. The CR2 version has built in limit switches which would be a nice to have and finally the CR1 version is just the basic valve with reversible motor. I believe based on his post and the fact that his valve has only two wires the original poster has the CR1 flavor.

    Ron
     
  13. Crazywizard

    Thread Starter New Member

    Jan 21, 2015
    11
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    By the way, the valves that I have are the 5 wire CR-05.
     
  14. strantor

    AAC Fanatic!

    Oct 3, 2010
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    You are missing something. It does reverse polarity.
    If RLY1 closes, current flows through the motors from right to left. If RLY2 closes, current flows through the motors left to right.
     
  15. strantor

    AAC Fanatic!

    Oct 3, 2010
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    2spdt2.png 2spdt3.png
     
  16. Crazywizard

    Thread Starter New Member

    Jan 21, 2015
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    That is excellent - thanks so much for taking the time to help me out. Your diagram explains it and will do exactly what I want.
    I humbly extend my appreciation to all involved, great work.
     
    strantor likes this.
  17. Reloadron

    Active Member

    Jan 15, 2015
    963
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    Hi Les

    Since you have the CR-05 versions with the limit switches I don't see where a timer is needed. The limit switches disconnect the valve's coil when the valve reaches full travel open or closed. Thus, I see no need for any timer functions. I would set this up similar to the attached drawing. The thermostat switch would be wired to turn RY1 on and off. RY1 is just a 12 volt coil DPDT relay, The diode is a snubber across the relay coil. I am guessing the limit switches in the valve are Normally Closed, switches like this generally are N/C and open when the limit is achieved, in this case Open and Closed. RY1 is configured to reverse polarity to the valves. I did not work out the scheme as to when the valve opens or closes with respect to the thermostat. If the valves work backwards (reverse from what you want) just reverse the coil wires configurations.

    Limit Switch Valves.png

    Ron
     
  18. strantor

    AAC Fanatic!

    Oct 3, 2010
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    That would be ideal if he had NC limit switches, but per the drawing he posted, they are NO. Where did you get your drawing? If it's from the manufacturer's website then we should resolve the discrepancy; are they NC or NO?
     
  19. Reloadron

    Active Member

    Jan 15, 2015
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    Yeah, I caught that:
    Limit Switches Normally Open.png

    What I used was a drawing I made and did indeed make it to reflect normally closed limit switches. Among others the above is what I found online. While muddling through all this stuff I did find one reference written by a user that led me to believe despite the drawing they were normally closed and opened on limit, which is pretty common. I would love to know? The only way to find out is likely power the valve till travel is complete in either direction and measure the switches and see how they actually work. Sometimes these little Chinese cartoons and data sheets leave a little to be desired. Either way can be made to work and eliminate a timer function but normally closed makes for easier. :)

    Yeah, the only way to be sure is actually measure the switches at full travel in both directions. If they are as drawn and given the choice I would have likely used an H-Bridge rather than relay(s).

    Here is another example. Sorry the image quality sucks but what are they getting at with the text? The image comes from this sheet.

    http://i01.i.aliimg.com/img/pb/851/294/527/527294851_633.jpg

    Limit Switch Text.png Limit Switches Normally Open.png

    Ron
     
    Last edited: Jan 22, 2015
  20. Crazywizard

    Thread Starter New Member

    Jan 21, 2015
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