marine electrician needs help with project

Discussion in 'General Electronics Chat' started by gazz50, Jun 13, 2012.

  1. gazz50

    Thread Starter New Member

    Jun 13, 2012
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    Hello can sombody point me in the right direction to find a circuit diagram to control 2 12v relays from 2 mom switches and the switch must activate a led to show when its on and turn off on the next press of switch and when the other switch is pressed it must turn other relay so you can turn it on and the other relay off from any of the positions it is for a boat lower helm and flybridge to control a light i dont know a lot about electronics but willing to learn.
    Many Thanks.
    Gary
    gazz Posts: 1 Joined: Sun Jun 10, 2012 6:53 pm
     
  2. chuckey

    Well-Known Member

    Jun 4, 2007
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    Ignore the LEDs, they will be fed of a relay contact. You need relays with multiple sets of contacts. Lets call the first relay RLA, wire one side of its coil to the +12V via a normally closed set of contacts on RLB. The other side of RLA coil wire to earth with the switch in series. Right you press the switch and RLA pulls in, but then drops out, so wire a normally open set of RLA contacts across the switch. Now when you push the switch, RLA pulls in and the shorting contacts short out the switch and keep it in. If RLB is energised the +12V feed to the coil is broken so RLA drops out. So wire up RLB its switch as per RLA, not forgetting to put a pair of contacts from RLA in the feed to the +12V to RLB.
    Now you have a pair of relays that switch and latch until the other switch is pushed, so wire the indicator LEDs from the +12V via a suitable current limiting resistor to the earthy end of the relay coils. Use a spare set of contacts to feed power to your load.
    Frank
     
    Last edited: Jun 13, 2012
  3. cork_ie

    Member

    Oct 8, 2011
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    Hello Gary,
    I am not quite sure of the exact sequence you require.
    My understanding is you have two relays and two switches at each station (Helm & Flybridge) Lets call them relay A and relay B and the switches AH ,BH, AF & BF.
    If you press AH or AF relay A will latch on and if you press AH or AF again relay A will switch off. Similarly BH or BF will turn relay B on/off Also if relay B is turned on it will cause relay A to switch off .
    Is this correct. If not perhaps you might clarify what you require and I will try and help you. I assume you would like to use standard 5 pin "cube" relays.
     
  4. gazz50

    Thread Starter New Member

    Jun 13, 2012
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    thanks for your help guys what i am looking to do is fit a mom latching switch at the lower helm of a boat that controls a relay and a mom latching switch at the fly helm that controls another relay both relays power up a light.
    i was thinking it could work like this you press one of the switches and the light comes on press the same switch again light goes out if you leave the light on and now press the other swich the lets say the one downstairs it takes the control from upstairs to you downstairs and then that switch could turn it in and off that way if you turn light on from one point you dont have to return to same switch to turn it off and if possible then you could take control of the light from either station and would it be possible to put a timer in circuit to turn light of if noone touched the switch for say 3 minutes.
    Many Thanks
     
  5. cork_ie

    Member

    Oct 8, 2011
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    It is far easier to use two single pole double throw switches, i.e. on-on switches. Take your power supply to the common of the lower switch, run a pair of wires from helm switch to flybridge switch and supply your light from the common of the flybridge switch.

    If you need to use relays, it gets slightly more complicated. You will need to run a wire from the NO contact of the helm relay to the NC contact of the flybridge relay and a wire from the NC contact of the helm relay to the NO contact of the flybridge relay.
    The moving contact (common) of the helm switch is powered via a fuse and the common of the flybridge switch supplies the light.
    If any one of the relays is switched on then the light will light. If both are on or off, light goes off. Again you can use SPDT switches. you will need an extra pair of wires to the flybridge, to provide a supply to the flybridge switch and a negative for the relay.
    If you have to use momentary push switches then you will need to make some sort of flip-flop at both helm and flybridge, so that there is a change of state in the power supply to the associated relay each time a button is pressed.
    If you wish to use a timer, there are several such circuits based on the 555 timer available online.
     
  6. gazz50

    Thread Starter New Member

    Jun 13, 2012
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    Thanks for your help yes i can do it using 2 way switches and a single relay to control the light or relays like frank said but i was hoping to use small momentry switches but my knowledge of electronics is small i know enough to think a pair of 555 timers outputing to trans switching a relay could give me the control i want but cant find a circuit on the net to match my needs i have had the circuit working on the bench from one station through a 555 but do not know how to pair two up it works how i described above.
    Many thanks
     
  7. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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  8. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    This is actually a quite common problem in house wiring. Say you have a light at the top of a stairway. You don't want to have to go UP the stairs to turn the light on, and if you go down the stairs you want the light on to light your way.

    So you put switches at both the bottom and the top of the stairs and wire it in a somewhat weird. You may have seen that in your house, and it's really a common way to do things. It doesn't take any relays or electronics, just switches and wires.

    If you Google "two way light switch" you will come up with a lot of pages to read. It may take you a while to find one that actually helps and speaks to you in terms you understand.

    Here's the basic idea:
    [​IMG]
    I don't think that is very helpful for you as it is a bit abstract and it shows an AC power as it is for houses.

    Here's another way to view it:

    [​IMG]

    Somewhere you already must have a switch to control the existing lights, either on the lower helm or the flybridge. It would be easier to start there to add this in, and that is marked STATION 2 in the schematic. You need to change the switch there, run a new 3 wire cable to the other location, and add a switch up there.

    I did not show indicator lights in either location so I didn't complicate this too much. If you want to go this way you will also need some 12 volt lamps that get wired between the lamp wire and common. Station 1 should have a common wire so both these available in both stations, so you don't need a 4th wire just for the bulbs.

    If you have a good local marine store not only should they have the switches and cable for this they can give you some in person guidance.
     
  9. cork_ie

    Member

    Oct 8, 2011
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    Here is a "push to make" "push to break" circuit you can use.

    You will need one at each station.


    [​IMG]
    [​IMG]
     
    Last edited: Jun 16, 2012
  10. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    That is one of the circuits in Bill Bowden's webpage that I linked to in post #7. You will not need one complete circuit at each station. Just one relay circuit and two push buttons in parallel, one at each station.

    Ken
     
  11. gazz50

    Thread Starter New Member

    Jun 13, 2012
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    Thanks for your help guys the 555 timer circuit in bowdens circuits will be fantastic for what i want i have set it up and it works from a single station but what i cant do is make the one station say the flybridge turn off if you happen to leave it on from the lowerhelm i am sure you could run a wire between the 2 555 timers so when one is on you toggle the switch it turns the other one off like a toggle system also is it possible to make it so the circuit is allways off when you power up the boat.
    Many Thanks.
     
  12. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    All you need is one 555 circuit/relay. You run a pair of wires from the pushbutton on the flying bridge to the 555 circuit, and another pair of wires from the pushbutton in the lower bridge. These two pushbuttons are wired in parallel and are connected in place of the single switch shown in the 555 circuit. Like in the "Single Transistor Relay Toggle Circuit" in my post #7. That shows how to wire the two remote switches.

    The reason I liked the single transistor circuit is, as Bill Bowden pointed out in his circuit description, that the circuit defaults to the "OFF" condition when powered up...as you say you want.

    Ken
     
  13. sheldons

    Active Member

    Oct 26, 2011
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    Heres a simpler way if you use spst switches.....wire them as a 2 way circuit and duplicate this for as many units as you want.....
     
  14. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Why all the electronics there? For that approach just use the two SPDT switches as ernieM and cork_ie outlined earlier, to switch the relay directly...or just switch the light directly. And that still doesn't give gazz50 the momentary pushbutton operation that he wanted.

    Ken
     
  15. gazz50

    Thread Starter New Member

    Jun 13, 2012
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    Again thanks for the help guys if i use 1 555 timer and 2 switches 1 at lowerhelm one at fly as detailed in bowdens circuit i cant see how i would wire the status leds for each station to say which station has control from one timer thats why i think i might need two 555 timers but i am not sure about that the reason that i cant use normal two way lighting circuits is the circuit will be controlled by touch mom switches.
    Many thanks guys
     
  16. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    You don't need an indicator at the switches. Both switches do the same thing. Whichever switch you're standing in front of has control.
    1. Your on the upper bridge and the light is off. Pushing the button turns it on.
    2. Your on the upper bridge and the light is on. Pushing the button turns it off.
    3. Your on the lower bridge and the light is off. Pushing the button turns it on.
    4. Your on the lower bridge and the light is on. Pushing the button turns it off.
    5. ...But your mate is on the upper bridge an wants the light on, so pushes the button and turns it back on. You immediately push your button and turn it off. After several rounds of off-on-off-on-off you exert your captian's authority and make him walk the plank. Another problem solved! ;)

    Ken
     
  17. gazz50

    Thread Starter New Member

    Jun 13, 2012
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    Thanks for your help guys ken you are right in what you say about the light and i have that circuit wired in the garage it works just as you described however the light what i was looking for was a led status light that only comes on to say witch station has control it is a nav light and need that for boring legal reasons if i cant do that i will go with the one i have got thati s why i was thinking of two 555 timers and 2 relays one at each station turn one on it drops the other one out if it has been left on.
    Again many thanks.
     
  18. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Wished you had said that to start. All this time I (and maybe others) were under the assumption that this was a light for illumination. So. where is this light located? Is there more than one light? Is this linked to both bridge controls? Maybe a little more about the legal and functional logic behind the indicator? I'll plead ignorance on boats and nautical requirements.

    Ken
     
  19. cork_ie

    Member

    Oct 8, 2011
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    Could well be one of Bill Bowden's circuits but I found it somewhere else, I think some guy controlling lights for a model train. Anyway it is academic, the circuit will do the job.

    Yes you are absolutely correct one relay would do the job but for a 2$ circuit all the possible issues associated with such a tiny current required to trigger a 555 over a long distance can be avoided by just making two circuits. I am quite sure there will be several other cables running in the same conduit ,from helm to flybridge and would not run the risk of false triggering.
     
  20. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    OK I Googled:flying bridge control indicator
    I got several manuals that stated similarly:

    To Transfer Control to the Flying Bridge
    1. Start the engine at the lower helm.
    2. Place throttle lever in center position.
    3. Press the control button at the helm on the
    flying bridge. The drive indicator light will flash.
    4. Put the throttle lever at the flying bridge in the
    center position. The drive indicator light will stop blinking and shine constant. This
    completes the transfer. You can now maneuver the houseboat from the flying bridge.
    Return control back to the lower helm in the same manner.


    So it looks like that there is more to it than two pushbuttons and toggling a light. The two relays you mentioned in post #1 are the lockouts for the opposite helm?

    Ken
     
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