Rewiring Emergency Exit Sign

The Rovering Member · 17th July 2019, 23:40

As per the title, an old cinema exit sign which charges the batteries when it's plugged in & illuminates when power is lost.
We want it to be illuminated when plugged in now, my current theory is to remove the 9v battery pack & replace with an equivalent transformer. As the supply to the strip bulb only seems to be 3-4v, l'm figuring there must be a step-down transformer in the circuit though why a 9v bulb can't be used l'm not sure unless it is one, it isn't marked. But the circuitry must also control the switching of the on/off power arrangement so my plan of leaving the circuitry in place may be a road to nowhere. A small transformer direct to the bulb would make sense but l'm wondering why the supply voltage to it via the board is so small.
Can anyone 'shine some light' on it for me please?

clf · 17th July 2019, 23:48

Quote:

Originally Posted by The Rovering Member

As per the title, an old cinema exit sign which charges the batteries when it's plugged in & illuminates when power is lost.
We want it to be illuminated when plugged in now, my current theory is to remove the 9v battery pack & replace with an equivalent transformer. As the supply to the strip bulb only seems to be 3-4v, l'm figuring there must be a step-down transformer in the circuit though why a 9v bulb can't be used l'm not sure unless it is one, it isn't marked. But the circuitry must also control the switching of the on/off power arrangement so my plan of leaving the circuitry in place may be a road to nowhere. A small transformer direct to the bulb would make sense but l'm wondering why the supply voltage to it via the board is so small.
Can anyone 'shine some light' on it for me please?

Could you not remove the internals, and use a small strip light in it? (it would need to be a non filament type to reduce the heat)

The Rovering Member · 18th July 2019, 02:03

Well the fluorescent tube that's in it is already ideally mounted & l wouldn't have thought it would be too much of a problem to change its power source & leave it in place.

17th July 2019, 23:40	#1
The Rovering Member I really should get out more....... Rover 75 saloon Join Date: Feb 2014 Location: London Posts: 2,953 Thanks: 263 Thanked 538 Times in 431 Posts	Rewiring Emergency Exit Sign As per the title, an old cinema exit sign which charges the batteries when it's plugged in & illuminates when power is lost. We want it to be illuminated when plugged in now, my current theory is to remove the 9v battery pack & replace with an equivalent transformer. As the supply to the strip bulb only seems to be 3-4v, l'm figuring there must be a step-down transformer in the circuit though why a 9v bulb can't be used l'm not sure unless it is one, it isn't marked. But the circuitry must also control the switching of the on/off power arrangement so my plan of leaving the circuitry in place may be a road to nowhere. A small transformer direct to the bulb would make sense but l'm wondering why the supply voltage to it via the board is so small. Can anyone 'shine some light' on it for me please? __________________ Reducing the size of my Rover fleet by adding a 75 to it. Last edited by The Rovering Member; 17th July 2019 at 23:42..

18th July 2019, 02:03	#3
The Rovering Member I really should get out more....... Rover 75 saloon Join Date: Feb 2014 Location: London Posts: 2,953 Thanks: 263 Thanked 538 Times in 431 Posts	Well the fluorescent tube that's in it is already ideally mounted & l wouldn't have thought it would be too much of a problem to change its power source & leave it in place. __________________ Reducing the size of my Rover fleet by adding a 75 to it.