Hi Adrian!

I have some more questions. Some of these questions aren't about the actual circuit, but they may help us help you better if the answers mean that we can look at other possible solutions.

Is this actually for a large-scale installation in a real hotel? If so, how many rooms must be serviced, and what is the expected range?

Is using the remote controls your idea, or the hotel manager/owner's? I ask only because it sounds like they already have something central installed.

Do you know for sure that you can get enough remote controls with unique codes/addresses/frequencies/whatever to handle all the rooms?

Why do you want to do this with relays and capacitors only? If semiconductors and ICs were allowed it could possibly be made smaller and cheaper.

What is your expected budget for each unit? What about the budget for the whole system?

What is your deadline?

What electronics experience do you have? Do you have the ability to load HEX code onto a microcontroller such as an 8051 or a PIC or something?

Would it be possible to use a rotary switch instead of a toggle?

I am sure I've forgotten some questions but if you can answer the above it might help us to help you.


Torben

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Ya know, when I was in the Navy we had this piece of gear for sat-comm stuff. Anyways I remember it had this really cool switch on it. It was 3 way, but middle position was push button. Now that would be cool, just can't figure out what you would call it. So it was like ON- PB -ON. I ordered a few switch catalogs to see if anything resembles what I remember.

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Brain fog is clearing. It was a rotary knob switch, with a center PB...

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Thank You so much

 

Hello again Adrian,

By "range" I mean how far must the farthest remote control be from its receiver.

I agree--wired would be more reliable. I don't know whether you can get the range, reliability, and ability to tell one room from another using the remote controls. Using microcontrollers and proper RF modules it should be doable but it's a pretty big job.

I thought the receiver was going to be in a central location? Are you saying that the remote control is going to be in something the customer can carry around the room? I thought there would be a switch on or near the door which the customer could use to control LEDs inside and outside the door, while the remote would send the state to a central location where all rooms could be monitored at once. Which is it?

OK, that opens things up a lot.

Microcontrollers might be the easiest and cheapest way to solve this problem.

OK, that's good to know.

Thanks for the answers, and if you can answer the above questions (and any others you think we might ask) things can move forward.


Torben

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Is this switch like the one shown in the attachement?

Attached Images

Push_Button_Switch.jpg (28.9 KB, 2 views)

 

Yo Adrian...

If I may make a few suggestions as well.

You need to lock down what you really need and why? You as the one being tasked to perform the design must know all the details of what is needed, such as number of rooms, remote interfaces, how is communication performed. Interfaces to the remote reciever. Before you can really pursue this to an end, a set of requirements must be determined. At this point, it seems as those we are spinning our wheels.

Do not think I am getting annoyed or anything, as I and most others here like to help. It's what we do, but my request to you is this. Nail down what you actually need, perhaps start with a system level diagram. Make sure you have the overall picture in your mind and on paper.

When you say to me that you are not sure how the remotes communicate I worry as it shows you do not yet have a good understanding of your own design. If you do not know, it is difficult to offer help.

Perhaps you should consider alternatives to your remote and look into wireless links designed for multi users. Or maybe even running wired multidrop serial comms.

What I am saying is that before we can help, you need a better idea of all the task and functions of your system. Take charge as Project Eng, set requirements, such as one switch for this, no that, etc.
Get what I am saying?

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Got link? I like to look at the data sheet. Cool

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OK, I've solved the problem as originally posted, but I do NOT suggest this as a final solution. This so-called "solution" is only because I was fascinated by the relays-only idea. That said, this solution does use two diodes and one transistor.

I'm too tired to draw the whole thing out including the DPDT toggle switch wiring but the following should illustrate the idea. I'll try to get the DPDT wiring drawn out tomorrow if anyone is interested.

This solution requires three relays (SPST, although I have used DPDTs in testing and the schematic shows SPDTs), one DPDT toggle switch (centre-off), one 2N2222, a couple of signal diodes, two 100uF caps, and a handful of resistors and LEDs. It's pretty bulky and a little power-hungry for my taste but I've just carried the idea this far to see if I could come up with something which could do the job using the original relays-only requirement. Also, this is running on 12V, because that's what my relays need. And one thing you can't see yet is that it uses Ken's idea for the DPDT switch to discharge the caps (although that problem seems to also be partly solved by the centre-clear addition).

In the schematic shown the LED resistors are chosen for low-power 2mA LEDs with no thought yet given to differing red/green LED current requirements.




Torben

Attached Images

final_relay_solution.png (10.3 KB, 16 views)

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Actually, my boss just want to know if such functions i asked before can be done.

the remote control set i used to test is somehow like these:

Attached Images

	2jkg-2.jpg (24.2 KB, 3 views)
	2u.gif (17.3 KB, 1 views)

 

Ugh Torben, you must be using real high res settings. Your image sends all your text way off my screen. My eyesight is not so good so I stick to 1152x864. Why two leds per trig branch? Does that setup up currents or something for the cap?
I still like my circuit as it only needs 10 parts, no relays. Not as bullet proof as yours though

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Sorry about the resolution thing. My laptop's native resolution is 1680x1050. I hoped that image would be relatively small but I guess not.

Nope, just one LED for inside the door and one LED for outside the door.

Well, like I said I don't think this is a good final solution. I just wanted to see if I could figure out a way to solve the problem as originally presented. Now I can free my mind of that particular problem and move on to more realistic solutions, which will probably look more like yours.


Torben

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From the pics, I do not see how you could ID one remote from another. Do you have link for remote?

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Back to practical questions. Good idea. I'm off to bed though. Night all!


Torben

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sorry, what do you mean ID? I can hardly find the datasheet of that remote, i will keep finding.

 

I mean identification. How will you know one remote from another? If they all put out same frequency and codes, it will be hard to know which room is requesting service. See what I mean?

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