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Ive got a radio-command garden programmer which controls the watering system. Ive built a bistable relay to switch on and off the water using a 24v system instead of the expensive recomended 9v system. This works fine.
the receiver of the programmer gives out a short 6v signal to switch on the water and another signal in the opposite direction to switch off the water. The signal is short and in each state the polarity is reversed. that is
ON = 6v on wire A , 0v on wire B
Off  = 0v on wire A , 6v on wire B

because the programmer can control 4 different things, I would like to use it for other things.
how can I switch on and off lights, for example, which would normally need a relay which uses lots of current and requires a permanently "on" signal.; as for a battery receiver this would not be a very good idea as lights are not switched on for a short moment, but usually for a whole evening. I do not want to use a bistable relay if possible. Does anyone have a better idea?

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Why don't you want to use a bistable relay?  Seems like a natural for your application.

If you had the skill to design a 24 volt control system, why can't you do the same for a lighting system?  Both require steady on controller power.  Can't you use the same sensing of the 6V controller signals, only drive a 24 volt relay instead of a water valve?  Depending upon the power required for your lights, you can cascade relays to drive a contactor of adequate current rating.

Can you tell us more about your controller and your limitations?

awright

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the original control signal is intended to control a 6v water valve which is a 2 coiled electro-valve. in the shops I could buy a very expensive switch which fastens onto the receiver ( which has 4 o/ps) thus being able to swich on garden lights for example. The nature of this signal is that it is short and 6v.
for on it is in one direction and in off, it is in the opposite.
it seems to me the only way would be a bistable relay with diodes on each input.
Is there a solid state idea for this?

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hi euro,
You can buy small encapsulated solid state modules for AC control.
There are different types that can switch from 2 Amps thru 10A at mains voltages.
They are fully isolated and rated for mains voltages.

The control voltage is Vdc from +3V thru +24Vdc, with a very small control current.

Hope this helps.

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thanks, ill look up this idea on the net, I suppose i'll have to do something to switch on and another to switch off, the prolbem is the type of control signal I have, I imagine these switches will switch on as soon as there is a signal in, but, if the signal stops the switch will switch off. Ive in fact bought a bistable relay which was pretty expensive and because the programmer and receiver for my garden has up to 32 outputs, I dont want to use so many relays. (even though I wont be using all of them, of course), but I would like something which is cheaper and smaller than relays and if possible NOT a mechanical device which will eventually, buried in the garden.

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Well, I certainly agree with the undesirability of burying a relay in the garden, but why would you have to do that?  Wouldn't the relay be located at the controller in your house, rather than in the garden?  Would you care to explain more about the details your application?

awright

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hi euro,
You can buy logic ic bi-stables, not very expensive, the bistable  output would 'latch' the AC module.

If you bury electronics, you should use IP68 rated boxes/enclosures, pay special attention to earthing and use a RCCB.

Whats the system for?

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hi euro,
You could easily construct a logic circuit using a couple of transistors and a standard relay.
The relay would work like a bistable type.

With the low current required for the transistor/relay bistable, you could have the transistor bistables
in a central control box, driving the remote relays.

With all that water around, dont forget the Residual Current Circuit Breaker RCCD, in the mains supply.



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hi euro,
You could consider using say, HEF4013 dual 'D' type flip/flop.[ with a transistor to drive the relay]

Positive pulse ON/OFF, they also have a RESET pin. Use a simple R/C on the RESET pin in case of a mains
blackout.

Your 4011, could restart in any state.

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ah ha!!!
Ive got it, I used a dual opto isolator, the +ve pulse goes into one, and the -ve into another. Now  ive bought the bits and got it all working, I can now say that the project is working and finished!!!
however...
it cost me more than a bistable relay!!
lol !!!
I spent 40

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