Hi there!

I want to create a lighting circuit controlled by a relay which has 2 selv ptm switches which will toggle the relay between energised and de-energised. I wish to switch max 400W lighting @ 230V. But the switching has to be 24V.

I have seen this system in France, where it is very popular for circuits having more than 1 switch position.

Having talked to a French forum, I have discovered the kit in question is a telerupteur, but don't think that kit is for sale here, as mostly we use two way and intermediate for 2 or more ways.

Also, ideally, I would like to fit the relay & 24V PSU in an enclosure with DIN rail (or even a quiet one.......groan....)

Can help?

 

I have no idea what it is that you want to do. What is a "selv ptm" switch?

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SELV is Separated Extra Low Voltage. I'm not sure about PTM.

 

Perhaps "Push To Make"?.

But like everyone else, I don't have a clue what he wants?.

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Right and right. Your guessed definitions of SELV and PTM are both correct. Thought ptm was common terminology for push to make in electronics circles?

I'm sorry that you don't understand things the way I'm describing them. Let me try again.

I want to use a latching relay to control a small lighting circuit (400W max at 230V). I want to use ptm switches (2 of) to turn the lighting on & off from either switch. Here's the important bit: The control circuit that energises and de-energises the relay's coil must be SELV - 24V is as good as any.

Are things clearer, or have I made things worse?

 

OK, I understand. It might be better to use a non-latching relay and push on-push off switch. Otherwise, you will need 2 switches for each latching relay, one for energized, one for de-energized. Latching relays are DC but the non-latching relay could be AC. Do you need the schematic?

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Thanks.

I'm away later today, but will read things soon. Chap at co called willow that do relays reckoned a latching relay would only need one ptm per switching position, and that pushing the switch would toggle between on & off ie energised/ de-energised.

Is this not possible?

Back in a week or so.

 

Yes, I have used such a relay in auditoriums and churches ( last man out turns off the light ) countless times. I believe both square D and Omron make such a relay. It's not really a relay its a solenoid ( Lo V ) and 2 cherry micro-switches that to toggle back and forth . You travel the ground and the thing will work with a hundred switch stations. I apologize as I don't remember the number but try www.grainger,com -->relays --->latching

 

[quote="securespark"]Thought ptm was common terminology for push to make in electronics circles?quote]

Well, I was pretty sure I knew what you meant when you said PTM. But I just call them push-buttons. Or, in your exact case, if you wanted to specify, I would say a momentary NO push-button switch. momentary means that it doesn't latch. It doesn't stay down after you stop pushing it. And NO means normaly open. Meaning that the circuit is open and not passing through the switch when it's not being pushed down. NC, normaly closed, is the other way around. Push it to break the circuit. You may have already known all of this, but..... whatever. :lol: Just tryin' to help.

Rain

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Cheers Electric Rain

I am familiar with NO & NC - I install Burglar Alarms as part of my job. I was obviously wrong in thinking that PTM (NO) was common terminology (RS trade counter understood!) The other is PTB (push-to-break, or NC).

Have you any bright ideas about this fancy idea of mine?? Or maybe you think I'm nuts, and don't want to say so!!

 

^-^ No, I don't think you're nuts, I just don't quite understand what you need here...

Edit: Oh, wait... I see. Well, would you be willing to use Push on-Push of switches? Because that'd be the easiest way. Then, you can use a 24V transformer for the power to the relays.

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why not power them from A.C. and use a circuti with a capactior, because the current is small, and probably the circuit will be insulated from direct contact?

 

B:

I need to keep the control voltage low for safety reasons (kiddies operating a "flying lead" switch, ie a momentary ptm switch on the end of a bit of bellwire.

If it helps, the French use this system for all their multi-switch lighting and their relay is known as a "telerrupteur".
One member of a french forum said this about the telerupteur:

We call this "télérupteur"

Each push-button send a brief 24v signal, each signal change the status of the "telerupteur", this status leave or stop the 230v line.


IE each pulse of 24V to relay either switches the light on or off depending on current (no pun intended!) status.


ER:

Surely the switches need to be momentary or else the relay will be energised until you push again? Hence the latching relay idea. And would your system work with two switch positions? IE switch on at position A and off at position B?

Sorry for the delay. Been away on hols/vacation.

 

Well, I'm not familiar with latching relays... I'm not sure what to do here.

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Sounds like what you're talking about is a 'lighting contactor'. It has two independant coils and no return spring. Energize one coil and the contacts (for the mains ) close and remain closed even though the control power is off. Energize the other coil and the contacts open . They are typically operated from a single pole double throw momentary switch. Because the switching action is momentary it's easy to wire in as many switches as you want without getting complicated, all switches are in parallel..The only ones I have worked with have been 120vac control and they switched 480vac lights..If you use some sort of latching circuit and the power flickers off for a few seconds someone will have to find the switch in the dark and turn the lights on :shock:

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