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computer Christmas lights


Well-Known Member
years ago I assembled a Compurterized Christmas light display but since sold the entire setup.
I recall the SSR or triac boards used an opti-isolator, couple resistors but instead of using a computer, I want to just use a PIC to drive the opti_isolator. Just started looking for leftover plans and parts but figure would ask first.
Given the hazards of line-voltage wiring, I'd suggest using off-the-shelf SSRs (Solid State Relays). A module like this one will be safe and handle any practical load.


Alternatively, going with a plug-in Opto-22 solution would provide a neater installation. You can find the boards and plug-in modules on ebay for a reasonable price.

s-l400 (4).jpg
looked at various items and looked at cost to actually build one.
I only need 10 opti-triac circuits and planning on putting all on one board with the pic (18f2221)
more research needed
I would strongly advise against a DIY approach to line power control. Small mistakes or a finger placed in the wrong location could have deadly consequences.

An alternative to Opto-22 is these 4 channel SSR modules, but they will only handle 2 amps per channel. For LED strings, this may be sufficient. That's 8 amps per panel, 16 amps for 2 panels controlling 8 channels, which is about the most you want on a 20 amp circuit (US).

I have used one of these modules to build a controller for a stop light (traffic signal). Personally, I put safety over cost and this was the safe way to control 120VAC × multiple channels.

something to consider.
thinking maybe build the wire frame , paint then add led lights then decide on controller.
could DIY then pot all the 110v connections.
This is going to be a "sign" for our town centennial July 2023.
Build a wire frame spelling out RYDEWOOD 100 YEARS using 1/8 inch steel rod bent to form letters then braze it all together. Add lights and add programmed PIC circuit
new enclosure idea to protect the high voltage circuitry.
Way back when I was building a computerized Christmas light display using an Olsen595 circuit board the optotriac circuitry was directly connected to the plug receptacle in a power strip. Just need to fabricate a 10-12 circuit board to attach to the screws on the side of the plugs after cutting the short tab on the receptacles.
a different line of thought
Why not look at going with 12 volt string of lights instead of 120 volt
Sets re available with 20 lights per string
maybe easier to control with PIC?
What do you need the lights to do? Just turn the whole thing on/off?

There are LED strings available that use a 2/3 wire serial interface that are controllable if you want something fancy. Some are easier to use than others.
Low voltage LED strings, LED rope lights,, LED tape or the newer LED "neon" certainly reduce the danger of electrocution, smoke and flames. And liability issues if you're planning on doing this in a public space.

I would suggest you spend some time with Big Clive on YouTube seeing how he has built different types of illuminated Christmas displays. You may not like his videos, as he explains the details at length, but they are necessary details for a success outcome that's not not a hazard.

Here are three videos that merely scratch the surface, but will provide a good starting point. Do understand these videos aren't exactly your project; the intent is to show some ideas. And they may not discuss every important bit; Clive has many more videos so if you decide on a path, search for his other videos to understand the details. Ouch – it makes me cringe just thinking there's any chance of that!

The first video uses LED rope light. It's the oldest LED technology, and one with some difficulties, like only cutting the rope at 3' intervals. Still, lots to learn here.

This video uses LED "neon" – it looks like old-school neon signs. A very cool look that's probably one of the simplest to use.

This video is an LED neon "how to" – Clive goes through the techniques of building an LED neon display. Lots of detail and practical knowledge.

the sign will be 10inches tall and 40 inches long.
Hopefully build a wire frame.
Sign has 9 letters RYDERWOOD
Thinking just flash each letter on independently then all on.
Have a pc board cutout like a birthday cake below the RYDERWOOD this would have red leds
I need to search by junk box as I think I still have the band project I did several years ago. It has an 18fxxxx dip chip and 20 Mosfets All designed for 12 volts with a 5vold 7805 regulator for the piv.
Thanks for the videos will look through them since I am basically on the DL list (torn meniscus in the right knee.
Glad you have found something that may work and is less hazardous than switching line power.

It's a bit curious that instead of Clive's videos – a professional in the field with nearly a million YouTube subscribers – you've referenced videos by a guy who grabbed the hot end of a soldering iron, is using something he calls "solderless wire" and who has only 10k YouTube subscribers. Whatever works for you.
the three videos you posted didn't got into detail on actually building the led rope lights install, but I like the idea of the hardware cloth.
I notice "pic control" if you want a user friendly way to change/control things like tempo & flash patterns, might want to install a wifi chip or a port to easy connect to pc (simple with arduino since it already has usb port common with most computers.) or maybe a few buttons are enough.

The thing i forget to wire in most often is the power switch.
this is a start on my project for an LED/neon sign.
have no idea of current draw of LED strips at 12 volts but the mosfet should handle it.
Not happy feeding the 7805 with 12 volts.


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