A programmable module for fade up/down on trigger?


Standard Member
Hi all, I'm currently in the process of refurbishing a small purpose-built Home Cinema.
I have virtually completed the lighting scheme for the Auditorium, and with exception of a few of the re-wired original lights, the whole lot has been achieved with LED strip.

The Screen is protected by motorised Theatrical Tabs when not in use, and I have designed a simple way of putting a decent amount of light on them using RGB 5050/300 sitting in narrow, home-made mirrored reflector troughs to get as much light as possible on the fabric - which is an olive green velvet - so not the best for light! but it does actually work better than expected.

One of the problems I am grappling with at the moment, is how to effectively automate the strip to fade in/out in sync with the Tabs.
The ideal solution would be a module that will change state over a programmed time period, upon a trigger pulse from say, a micro-switch at the head of the Tab track. This wiould also give Me the ability to over-ride the microswitch remotely when needed.

The nearest readily available item I know of, is the circuit used in touch dimmers, but their routine is cyclic, in that is they will only run at a pre-determined rate, and wont change state by a gradual fade up/down upon a momentary touch.

As I see it, I only have 2 realistic options to achieve this; 1, to go down the (time-consuming?) arduino route, or 2, to build a mechanical assembly with simple slip-clutch on the Tabs motor (or cord) to operate a potentiometer-based solution. (a bit Heath Robinson I know, but if it works...)

Any thoughts from those Who have solved a similar problem will be very gratefully received. :)


Prominent Member
There is a 3rd way, use a lighting controller. You would then program the "scene" to operate off the switch-input and call your scene with the required fade rate. I work with Helvar equipment so could do this with a Digidim power suply, Digidim dimmer module (of whatever type to suit the load) and a Digidim mini-input unit (which could call one scene when the switch contact closes and another when the switch contact opens).

I'm sure many of the other lighting control system or electronic faceplate dimmers would have similar features providing they allow for external switch inputs to be wired to their products.


Standard Member
Hi Neil, thanks for the quick reply. Wow! those digidim units are amazing - very adaptable and great design too, but boy, are they out of My league!! the nearest to these I've seen were on a job where a simpler Philips version were being installed in the London Rafael Hotel a couple of years back, and they were pretty impressive then.

This project however, (being done as a favour for friends) just doesen't have the luxury of the budget those kind of units require, which leaves Me trying to find 'creative' (i.e penny-pinching) ways around these problems!
With Christmas looming, and the projector itself to install/set up in the next few days I may have to postpone the Tabs/lights/sync issue for a while, But I know that if I can crack this probem, it'll really make for an impressive, 'theatrical' start and finish to Film Shows.
And when that's done, I can deal with the Safety Curtain!!

The latest video from AVForums

Amazon Fire TV Cube Gen 3 Review: Coming Soon
Subscribe to our YouTube channel
Support AVForums with Patreon

Top Bottom