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I understand your requirement is to produce a timed on pulse whenever the switch transitions on to off OR off to on.
Excellent toolbox parts solution. I have in mind a single-package solution using an LM339 - a=input buffer, b=inverter, a couple of diodes and c + d=window detector.

I have to admit that many of my quick solutions these days are just PICs. As much as I like to design circuits, I can usually get there faster by programming. On one occasion I had so little time to make a gizmo to send abroad, I built the hardware and sent an in-circuit programming cable with it, then while it was in transit built a copy, programmed and debugged it and then sent the hex file for the end user to upload. At the moment of dispatch I hadn't actually worked out any of the logic or math, and there was quite a lot of floating point that I didn't have a hope of programming in time. By building generic hardware, I didn't need to think about it at that stage.

But I do like tricky hardware solutions. I am seeing an opto-isolator inside a bridge rectifier, maybe a unijunction transistor. How about a couple of ECC82s? What about triggering on the transit time of a C/O relay contact? Two mercury switches connected by a spring?
To my great shame I have never designed nor constructed or worked on small thermionic valve circuitry. The larger tubes yes. So I will leave the ECC82 technology demonstrator for you to do.

For tireminnanzi - the Italian made bticino gate control system I have worked on only required brief negative going pulses to trigger the controller to do something. Ie. Signal line was normally high at say logic 1 5Volts and when it dipped down to 0Volts ie logic 0 the logic circuits detected this and registered it.

As Lucien has said we really need a much better interface specification from you. References and drawings or sketches would be nice to look at.
 
So I will leave the ECC82 technology demonstrator for you to do

Seeing as you've kindly done the quad comparator one, I can't really quibble. TBH the only implementation I would ever get round to doing is the PIC 12F675. I got as far as looking in the drawer but didn't have one. I do have plenty of ECC82s (one of my organs uses 174 of them) but not the time to design and make the coupling transformer.

Of course if it's all going to happen at 230V AC rather than logic level, valves are clearly the way to go. Or I suppose the output could be a little TO-92 triac like a Z01xx but where's the fun in that?
 
tireminnanzi - good evening Sir.

Is this a search for a solution to one installation‘s problem or for many installations which use the switch you mentioned?

This week I will construct your idea in #15 and report my findings. Are you able to confirm the duration of the pulse and also its waveform. I am being pedantic but the detail matters and could help achieve simplicity and a low component count.
 
By ‘gate opener’ do you mean ‘lock’ for security? Or do you mean servo actuator to open the gate using electrical energy?
 
By ‘gate opener’ do you mean ‘lock’ for security? Or do you mean servo actuator to open the gate using electrical energy?
Hi Marconi,
the solution should be used in all the installations that require a pulse of some seconds and a button is not available in the producer catalog, only a multiswitch.

For gate opener in this case I intend a sort of electric door opener, it unlock a door, it doesn't control a motor.

Best regards
 
Building on Tireminnanzi’s idea in #15 here is version 3 using two relays, two diodes and a capacitor to produce a circuit which will momentarily close some no volt contacts whenever a switch is turned off to on and also when next the switch is turned on to off. In my circuit the red spst dip switch bottom right is this switch. Power applied ie switch is on is indicated by the the right hand red LED.

You can hear the no volt contacts closing and opening each time the switch is operated on/off or off/on.

I added in a storage capacitor which is charged up whenever the power is applied ie the switch is on. It is this capacitor which powers the left hand red LED to indicate the momentary closure of the no volt contacts.

So with a 230V ac switch line converted to in my case 12V rectified and smoothed dc - by my power supply box - this circuit will close the no volt contacts for a time determined by one capacitor whenever the switch changes state.
 

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Ah, the two relay solution. I got as far as two relays lying on the bench. To minimise the power supply requirements, one might want to use 48V relays powered by a capacitive dropper, however in small sizes 48V coils puts the price up significantly. 24V is probably the sensible choice, but I wonder whether the two coils could be wired nominally in series and individually shorted to de-energise? This would halve the dropper current compared to parallel operation.
Does exist on the market a differentiator device? 16291216457646511635461868947053 - EletriciansForums.net
 
A quick gander at electrically operated locks and it seems they generally operate 12 or 24 V some ac, dc or both. In which case they normally have a dedicated power supply connected to the mains and switching and powering the locks are done by 12 to 24V circuits.

Power opened doors and gates I assume can use actuators energised by the mains or lower voltage - my brother in law’s are mains voltage electric motors. Where my friend lives in a secluded controlled access development the gates are 12 or 24 V dc motors IIRC. Signalling for both of these actuators to operate is done at safe voltage levels.

It is not explained by the OP why he is using the mains voltage to signal a lock to be opened. Further it is not clear whether the exact requirements is just to signal a lock to open - it already being supplied with a power supply - or to actual have something between the mains energised on/off switches he mentions and the lock without a power supply to briefly energise them even when the switch transition on to off - Which of course demands energy storage as part of the requirement. I was suggesting this by the storage capacitor added to my version 3 to power the indicator Led for the NVC.

ps (I am assuming a switched line and neutral only).
 
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Tireminannzi: Version 3 functions in a way which I think is close to your switching requirement. Since making it I have had an idea on how to dispense with one of the relays which would reduce the component count. I will have a go at a version 4 tomorrow.
 
Here is version 4 using only one relay. It takes a switched line and neutral, albeit for safety I use 12Vdc instead of 230Vac, and closes some volt-free contacts briefly every time the switch transitions on/off or off/on.
 

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Here is version 4.1 which switches 230Vac - you can see and then hear the 13A socket outlet supplying the bell transformer being turned on and off and on…. a few times. The two red LEDs indicate the pulsed output (left one) and the state of the socket switch (right one).

The 230Vac is transformed to 12Vac and then full wave rectified before being connected to the differentiator circuit as switched line and neutral.
 

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tireminnanzi - good afternoon Sir.​


I have an idea for a differentiator using opto-controlled transistors or thyristors. would you like me to ’cobble together’ a demonstrator of it - should it happen to work of course?
 

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