Lux Meter and Light Dimmer

[Darkness]

Say I have a large building with dimmable high bay lights installed, how can I automatically reduce the light output of the lights at certain times or if the lux falls to a certain threshold?

 

[motorbiking]

Assuming its multiple lights, you could put a PIR sensor inline on some of the lights so that they automatically come on, when its darker and people move.

The other option would be to use smart lights and an if this then that ITTT app.

 

[RandomGrinch]

Sorry, not helpful - but I know it is totally possible!
My local IKEA 'underground' car park does exactly this, on an industrial scale - raising the lighting level in zones as you walk underneath and then dimming as you leave!

 

[oldbutnotdead]

You need to be looking at industrial control systems, very unlikely to find what you need at B & Q or the like. Your requirement is not uncommon and completely achievable, exact solution depends on how the dimming on your bay lights works.

 

[Darkness]

Is dimming not achieved by reducing the voltage?

So I need to find a component that can drop the voltage to the lights based on a conditional input.

 

[oldbutnotdead]

Is dimming not achieved by reducing the voltage?

So I need to find a component that can drop the voltage to the lights based on a conditional input.

Not necessarily. If they are filament lamps then yes varying supply voltage can be used to vary output. If they are fluorescent you'll probably need some sort of controller specific to the brand to 'talk' to the individual ballasts (I've used various different types). LED- either vary the CURRENT (not voltage) or again you're on addressable fittings.