Hello!  I am having an issue with a very much unusual item. I have a Grimes/Boeing 10-0067-7 emergency exit sign that came out of one of the first runs of the Boeing 737 aircraft (1967-ish).

My proposition is that I would like to try to run it off of house power, if that is possible (I do have several low-voltage cell phone chargers...under 10v).  Problem is, it has 6 pins on the back, numbered "1,2,3,4,5,7".  It looks to have 4 bulbs in it, two sets of each type. (Large incandescent bulbs are GE #1315).  If anyone can help me out as to how to light this little thing up again, I would be greatful!  I was told by someone else that it is meant to blink, and not remain steadily lit?

Those two gray (and they are gray) wires, one goes to the big clear lamp on the front, the other goes through the middle group of wires, and connects to the other big clear lamp.

The ones on the right...(the side with the block of pins)...each go to those tiny white lights on the top of the front. The other red wire on the left, where my finger is...it goes into some brown box (ground wire?)

Here's the link to the album:  http://s1223.photobucket.com/albums/dd513/Grimey/

Like I said, it's somewhat of a long shot and I am hoping someone might have worked for Boeing, or is familiar with how they are wired, and can tell me if this is possible to do.

Ok, the lamps are 28V lamps, as this is the common aircraft DC bus. It is very likely the lamps will be straight 28V bulbs. The flasher there is for flashing the one lamp, and this would be a red coated 28V lamp. The other lamp is clear and thus in an emergency the unit would flash bright and dim in red and white. The 2 white lamps are lighted when the DC bus and the cabin lighting is on, to show the sign is active but not in emergency mode.

You cannot run this off 120V, as the insulation is not up to the task. You can however run the white lamps off anything from 12-24V, or replace them with white LED or 12V low power ( 1W max) lamps. Then you can use the unit. Getting it to flash would mean you need a power supply capable of supplying 24V at 2A or so, as the lamps used do draw over 1A when switching on, and no cellphone charger will do. A laptop power supply will do, but the lamps will be a lot dimmer ( may be good in a darkened room) as it generally gives 19V or so.

From what i can understand from this circuit :

"1" is main +V for the transparent lamps. The lamps however won't light untill enabled by the rest of the circuit

"2" enables the transparent lamps to light when voltage (possibly lower than in "1") is applied to it, but can be overriden (and the lamp kept off) by the circuit of "3" and "4"

"3" i think momentarily overrides "2" and is supposed to quickly extinguish the light once (then the light comes back on) when power is applied to it. "4" momentarily disables "3". It is possible that "3" and "4" are used for the flashing feature - with some more circuitry connected to them. The resistors and capacitors there are some form of timing filters. They can make out 1 pulse each time power is applied (for a sigle flash etc) but they dont look like a multivibrator (flasher circuit which can keep flashing permanently on its own), i also dont know of any multivibrator circuits made of just 1 transistor

"5" is main -V / earth

"7" is +V for the white lamps, it works on its own unaffected by "2"/"3"/"4"



The red wire is powering something (maybe a buzzer ?). It is not earth. The black wire however is earth

The switch controls whatever the red wire is connected to. In "ON" it is powered straight from the "1" main power supply, in the other position it is powered together with the transparent lamps and controllable by "2"/"3"/"4"



Voltages are no way more than 50V as thats the rating on the capacitors. I'd guess that "1" is somewhere around the rating of the transparent lamps, "2"/"3"/"4" may be lower (perhaps down to 3V or so - i dont know), "7" is the rating of the white lamps - if you dont know start with 3V and go up slowly

The lamps in there are most likely supposed to be dimmed a bit for max reliability and life. So dont power them at the brightness (color temperature) of normal incandescents but less

Thanks for the info!  I will try using a laptop power cord.  I have one that is on it's last legs, but i don't know offhand what it's voltage is.  I do believe these signs are somewhat rare, so I want to tend to keep it original as possible, and not do any modifications. I don't care how dim it is, just as long as I can get it working again.   When I connect a cord, if I find a cord, I would just connect the appropriate wire and wrap it around one of the numbered pins, yes?

If I do run the lamps from a 12v wall-wart power plug, what pins would I connect the positive/negative wires to?

The connections are

For the transparent lamps :
"1" +V the voltage at which you want to run the transparent lamps (their rating or less)
"2" +V the voltage needed to switch the circuit on
"5" -V/earth

For the white lamps :
"7" +V the voltage for the lamps
"5" -V/earth



For the transparent lamps :

Voltage on "1" can be anything from 0 to the voltage rating of the transparent lamps. You choose at which power you want to power them

A wall wart is ok for this purpose as long as its A / mA rating is ok for the lamps (assume that the lamps take the same current at any voltage - This is not true at all but the error is to the safe side)

Connect the wall wart + to "1", - to "5" and short between C and E terminals of the PNP Germanium transistor to get the lamp to light. Watch its brightness, this is what you will get with this wall wart. (Get a bigger one now if you want brighter light)



The voltage on "2" is tricky to find. Voltage on "2" have to be in some range - from something to something

Too low voltage may cause the incendescent lamp to dim and this will damage the circuit (because the power that is not getting to the lamp is lost on the PNP Germanium transistor - it may not be meant to deal with this power loss). Too high voltage will simply damage components as too high voltage usually does

So get batteries (where you can add one battery each time), or a wall wart where you can change the voltage (with the voltgage selection switches etc)

While power is applied to "1", poke the +V of 2nd power suppply to "2"

If the voltage is WAY too low, nothing will happen

If the voltage is too low, the lamp will light too dim (dimmer than when you shorted the transistor)

Try voltages higher and higher, starting with 3V and adding 1-2V at a time. I think it'll behave like this : up to some point the lamp will be brighter with higher voltage. At some voltage it will light at the max you can get, and if you try higher voltage it won't make the lamp any brighter. It is possible to happen somewhere around 12V maybe but dont take my word for it, try from 3V and up

Anyway it is important that you really find this voltage at which the lamp reaches its final brightness. If you stopped at 12V and the lamp is brightest, still check it at say 13.5V (12V + additional 1.5V battery) to see that the lamp is really brightest at 12V and does not get even brighter at 13.5V

Now that you found the  voltage at which the lamp is the brightest, the correct voltage for "2" is just a bit higher than that. So if for example you found it to be 12V, you need about 13-16V there. If its 5V, you need 6-8V



For the white lamps it is simple, just apply the voltage thatsb right for the lamps, + to "7" and - to "5"

28 volts is a tricky one to come up with, but 24 would probably be close enough, and that's easy to do, at least to fire it up and see it work.  You could pick up a pair of 12 volt lantern batteries (or four 6 volt lantern batteries) and wire them in series to get 24 volts.  A pair of D cell batteries in series with that would give you 27 volts.

Wow!  If I would have known it was this complicated to do, I would have never bought it!  Geez!

You can power "1" with 12V its just that the light wll be dim....