Need ideas for hidden switches.

Ok, all the mystery and sci-fi buffs out there, I have a mission for you!

I am working on something that will require a pair of momentary switches.(contacts of some sort to complete a path will do) These are relay voltage, and in the 500 mA range and will be wires with phone cable with a modular plug on the end to be plugged into a phone jack.

Here is the set, home office, 1940's theme. Think detective office / Indiana Jones desk ect... Either something that will sit on the top of my desk, or on the wall. I have had two thoughts to get your mind rolling. First was a skull with smal normally onen switches in the eye sockets. My wife however was not pleased. My next idea is pretty cool and requires the use of harder to find, normally closed relays. This thought was to make a desk pen set that had 1/8" mono jacks in the base of the funnel, and the "pens" would be tipped with a 1/8" mono plug. When the pen is removed, the circuit is cut to the relay, thus closing and completing the circuit until it hits the limit switch to kill the circuit again. One pen for one switch, the other pen for the other switch.
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Right about now you are thinking what the heck IS he trying to do! Well, I will clue you in. I have a hidden space in my office behind my desk that holds my printer/fax, cpu, and modem. There is a 24x36 picture over the opening that is mounted on ball bearing slides. The photo is raised and lowered by cables and pulleys. I plan to use a modified car window motor to motorize this. One switch will raise the picture to reveal the computer stuff, the other will lower it. Both directions wil raise until they hit limit switches and kill the switch wire.

Here are some photos, it is a work in process, but will be painted soon and with luck, wired with a super cool switch to operate the frame! Simple hidden switches under the desk will no do! :eusa_clap


and closed with the picture in place...

Are you going to be able to reach that equipment across your desk? Or does your desk fold up with another switch?

Wireless switches?

Interesting idea.

Have you considered a fake/hollowed-out book with wireless switches hidden within the book?

Or hide the switches under the edge of the desk, a la panic buttons in banks...

Or a small statue on a base, attached to the desk, you rotate the statue a half-turn...

Or in a cigar box... that looks like a regular cigar box, or not.

Or one of those boxes with buttons on it for an intercom - "Miss Farberbush, take a letter!"...you might find a vintage one.

OK, Mr. Engineering Person chiming in here.

1. Car power window motors will require two things : First, a 12 volt power supply, and second, a relay/switch with more than 500 mA current handling capability. No matter what the listed amperage for your motors, in-rush current at start up will be double that.

2. You DO NOT want to run that kind of current through a little audio type jack and plug. Very bad things could happen.

3. Where are you planning to mount the motors? You will presumably want the wiring, motors,and power/control circuitry concealed, so best to do that before you do any more work on that wall and cubbyhole.

4. Consider the cooling issue for your PC. If you run it for long periods of time in an enclosed area, you will shorten processor life. (15 years in the IT world, trust me on this)

I would be happy to help, if you wish. PM me if you want.

First, yes... for the most part I can reach what I need to just fine. (The floor will be raised about 4'-6" this summer and make it even easier to reach. I may also make a pull out shelf for the printer, but I hardly ever use the fax feeder. I have a digital fax that I use to sent as an e-mail off my lap top.

Switches under the desk? easy, but far too simple... I want something that makes the switches seem like the cool part. Statue is a good idea and one I have pondered. I like the base part, that has possibility's. Cigar box would take up too much room and I don't smoke, the intercom might work but not secretive enough...


The book is a good thought, many things can be hidden in the box, even dual layers for other hidden "goodies"... Hmmm

Keep the thoughts coming!

Do you have a HVAC/R tech friend nearby? We use relay's that have two sets of contacts. Normally Open (NO) and Normally Closed (NC) along with the common. You also might need a "switching relay" type setup. Like is used with boiler circulator. 24v ac provided by a transformer energises the coil in the relay when the thermostat is turned up, the coil closes the contacts on the 120v side of things allowing 120v power through to the circulator. At no time is the amp load nor voltage to the circulator run through the thermostat. By removing the pen and breaking a 12 volt circuit only pulling enough amps to hold the magnet up on the coil you will cause the magnet to drop, the NC contacts would return to the "off" state completing the circuit to your motor. How are you going to reverse the motor?

Matt

Well, from what I have been able to find (In Celsius) is that anything under 60c degrees is ideal. My "unscientific" testing has been running the temp inside the computer at 37c with a digital meat thermometer probe inside the case. What is not apparent is that I have air flow under the frame and close to a 1" air gap at the top. because the picture and board is shimmed away from the tracks. The tracks are mounted to the wall and not flush, this keeps the bottom away about 1/2". My secondary fan only comes on in heavy use, as it did before. For now, I hope the airflow is enough... it is more than my old computer desk and the cpu ran inside that for about 6 years. I can add more air flow with duct work if needed.
*** If you have a better ideal internal temp, please let me know... I am going off inside case air temp, but it seems to be running just a bit above 50% of the max temp right now.

Now the motor, the motor should draw less than 10 amps by itself so a regulated power supply, or a car battery with a trickle maintainer will be more than enough. The 500mA is the switch side of the relay, that will not be suspect to inrush voltage, and the relay will be a 30a relay itself. However, the switching side of the relay is rated for 500mA. The relays will, in fact, be auto relays designed for this type of use. (In fact, I just looked it up and the relays have a 150mA draw in use) In rush for that side to activate the relay is very slight. The audio plugs are 100x heavier than the tiny switches that alarm systems use, and those switches operate the very same relays.

On the back side of that wall is a small storage closet so I have full access to mount the motor back there. The design will require me to fabricate a new shaft for the motor so I can attach a pulley to the shaft. I have a couple lathes in my shop, so the new shaft will be simple.

PS, here is a photo of the wire chase I installed for the wires to exit the box behind my desk. In use, it has two wood covers that screw on to cover them all.

Vornholt said:

OK, Mr. Engineering Person chiming in here.

1. Car power window motors will require two things : First, a 12 volt power supply, and second, a relay/switch with more than 500 mA current handling capability. No matter what the listed amperage for your motors, in-rush current at start up will be double that.

2. You DO NOT want to run that kind of current through a little audio type jack and plug. Very bad things could happen.

3. Where are you planning to mount the motors? You will presumably want the wiring, motors,and power/control circuitry concealed, so best to do that before you do any more work on that wall and cubbyhole.

4. Consider the cooling issue for your PC. If you run it for long periods of time in an enclosed area, you will shorten processor life. (15 years in the IT world, trust me on this)

I would be happy to help, if you wish. PM me if you want.

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Matt, those are the relays I am thinking of if I do a system that will require the relays to "open" when switched.

A car window motor reverses direction when the polarity is reversed. So I will need to separate the wires via relays. I must use four to do this. One pair will switch the wires in one direction, the other will switch in the other.

Maybe a vintage table striker lighter. Pulling out the striker could trip the circuit to raise the picture.

Sounds like you need a two pen set. One pen "Opens" one pen "closes"

Matt

If you really wanted to go complex, retro and non-obvious, you could have your switches triggered by a thermocouple built into a Sam Spade-style desk lighter or perhaps a Brandy warmer.

You would have to wire it so the thermocouple triggers the switching action so you didn't have to keep the lighter or warmer lit to keep the compartment open.

Former mechanical engineer here:

All those contraptions eventually break down and have to be fixed or replaced. Usually at 10 pm on a Saturday during a blizzard.

Paisley said:

Former mechanical engineer here:

All those contraptions eventually break down and have to be fixed or replaced. Usually at 10 pm on a Saturday during a blizzard.

Click to expand...

That you are right! But I think the whole point of this is the coolness factor. And sometimes one has to sacrifice reliability for coolness.

Matt

How about this...


:eusa_clap :eusa_clap :eusa_clap

lol
sorry, it's way past my bedtime!

MPicciotto said:

That you are right! But I think the whole point of this is the coolness factor. And sometimes one has to sacrifice reliability for coolness.

Matt

Click to expand...

EXACTLY! Plus, even with the motor, in the worst case, I can go back to a balanced weight like I have right now if it all fails. However, it will be a rather basic system that should not be to problematic.

The clapper, good gawd... now you want me to give my office the clap~ lol

PS, Matt... in the begining when I spoke of the two pens, I was thinking about using two.

I did have a thought while driving around today. I could build an art-deco style picture frame (square frame with a series of "pillars" stepping down on each side of the frame. Then I could pivot the frame in the center at the sides and install a car window switch that engages the bottom of the frame. Tilt the frame back to go up, and pull forward to go down. The problem would be leverage and weight. I have a feeling that the frame would not be heavy enough to activate the switch whithout holding it down. [huh]

Refinement on Vornholt's concern: use the pen-switches to trip a smaller relay, which in turn trips the bigger one.

(Former electronics-tech student, working on some advanced automotive-derived projects of my own)

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as an inventor of bizarre Macgyver type contraptions myself ... a thought would be to use a couple of push type buttons, that light up and add it to that vintage phone on your desk, making it look like 'extension buttons' or you can go with a old style pulley & weight system used in vintage pane windows by adding some floor length drapery as your window treatment you can incorporate some extra pulls on either side of your windows, hiding the cords in plain sight, they would have to be run inside your walls of course or you can build a trough for it [huh]

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No need for extra relays, really guys... the switch side of a typical 30 amp bosch style relay is just 150mA and does not need much wire to run. Think about the power that your cell phone charger, or any AC adaptor uses. It is the same design of a plug as a 1/8" mono plug and in fact, it is far heavier than most. They can handle it, and maybe 20 more to boot.

I do have the picture on a cable & pulley system now which uses a counter weight exactly like the old fashioned windows. My plan it to just replace the counter weight by wrapping the cable onto a pulley and let it out and reel it in via the motor.

I had thought about the phone buttons, but that phone is a matching number 1958 so I would hate to cut it up.

They're not common, but how about a vintage Bell 302 model phone with the multi-line buttons at the front? Wire one button, for raise, one for lower.