back to home emergency lighting project

5 power and control:


Power wires from all 8 lights come together at one pole in the basement, right by a big deep cycle battery
that is kept on float charge for emergencies. I made a simple board with just a relay, a resistor, and some
wire compression strips. Power is supplied from a little USB power brick from an old cell phone. The USB
power supplies 5v to the board, and the resistor cuts it down a bit to keep the 3v relay engaged. When the
relay loses power, (when utility power fails) the relay falls, connecting the common and NC together, which
provides power to the wire strips.

I also ran one more wire upstairs to a box I attached to the wall, with a toggling push-button switch on it.
The switch is wired in series with the USB power to the relay, so I can toggle the switch to its Open position
to simulate a loss of utility power, to turn on the lights. The box is a lot bigger than it needs to be for
this, but I intend to mount more things to it. There's enough room for a 3.2" arduino TFT touch screen and
the arduino will fit in that box, so I might add some more home automation type things in there later.

But for now it's very satisfying to turn on the lights at night right before bed just to give them a test and
see how well it lights up the whole house. I've left all the lights in their "LOW" intensity for now, but I
get the feeling I'll be grumbly the first time the power goes out at 2am, lighting up the house and waking me
up. But we'll cross that bridge when we come to it.

As currently designed, I can't turn OFF the entire system from the switch, the lights will have to be turned
off individually. I suppose I could replace the SPDT switch with one that has a center-off position, and run
(resistored) 12v from the battery up to the switch too, to allow the battery to engage the relay, as a "mute"
button, so to speak, for the light.



1 controller wired up:


2 wall control box (keep it simple, just one big red button):



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last updated 08/13/2023 at 09:07:05