A very interesting musical Christmas decoration light circuit can be built using a single IC, and some other few passive components, let’s learn the details as furnished below.
By: Ritu Panday
How it Works
The circuit of a selectable muti-musical song player with 5 sequential light pattern generator is discussed here using just a single chip M668, and a few resistors and BJTs. The sequential light control also exhibits multiple patterns depending on the pressing of a button, and this is executed through 5nos of SCRs and lamps.
The lamps are in the form single 10 watt filament bulbs or even colored 1 watt LED bulbs might work beautifully for this application.
Referring to the diagram the IC M668 may have 25 different Christmas melodies or songs embedded in it, which is played randomly as long as the circuit is powered.
Additionally the button TG can be pressed anytime for changing the song number, and playing any other desired number on the connected loudspeaker.
The loudspeaker is a tiny 32 ohms speaker, which is driven by a BJT amplifier capable of producing an adequate ½ watt power over the speaker which may be quite enough for anybody to listen to the melodies within the premise.
The VOL button can be used for adjusting the volume as per individual preference and tolerance.
The best thing about this musical Christmas light sequencer circuit is not only its dual function feature of music and light generation but also its transformerless compact design.
The power for this decoration light circuit can be directly acquired from the AC mains through a little transformerless power supply circuit comprising of some diodes and capacitors as shown below:
Mains Power Supply Connection Details
As can be seen , direct AC mains Vdd1 is used for powering the AC lamps, therefore make sure the connected lamps are rated at 120V AC, or 220CV AC and not anything less than that.
Vdd is used for powering the IC based circuit and is therefore stabilized to 12V, however care must be taken not to touch the circuit while it's powered because this musical Christmas light decoration circuit is absolutely NOT isolated from mains, and therefore is life threatening in open condition.
This implies that the whole circuit must be enclosed inside a suitable enclosure with only the mains cord terminating for AC plug in.
The lights could be terminated through wire and bulb holder arrangement and here too care should be taken to perfectly insulate the individual bulb strings and holders so that no accidental shocks are encountered while decorating the lights over a Christmas tree or any similar desired position.
The following image provides the list of songs that the IC M668 may have embedded in it:
Soledad Cook says
Hello Swagatam,
I am a scientist and artist that needs your help. I am currently designing an installation for a Science communication program. The installation I want to produce involves a series of LED lights that should turn on and off following the sound of a beating heart.
Doing my research I found your website and I figured a similar system to the one you describe for Christmas lights could work well for my purpose.
Would you be interested to help? I have the design of the installation very clear, but I would need a quick explanation of the materials I need to purchase. I would be happy to pay you for your time and expertise.
Swagatam says
Hello Soledad, You can probably need the following concept:
https://www.homemade-circuits.com/wireless-music-level-indicator/
But the problem is that the heart beat cannot be easily amplified. For this you may try building the following design and then link it up with the circuits explained in the above link:
https://www.homemade-circuits.com/electronic-stethescope-amplifier-circuit/
The above designs are not practically confirmed, so if one these ideas is practically confirmed then the desired circuit can be quickly implemented
Soledad says
Thank you for your reply, it was super helpful 🙂
Swagatam says
No problem, glad i could help!
Martin says
You mentioned that list of songs that the IC M668 may have embedded in it.
How are the songs embedded into it?
Does the IC already come with songs embedded in it or can they be added to the IC some how?
Thanks.
Martin
Swagatam says
It will come pre-programmed with a set of tunes from the manufacturer, no user programmable feature is available in this IC
Martin says
Okay, thanks for getting back to me about it being pre-programmed with a set of tunes from the manufacturer.
-Martin
Swagatam says
You are welcome!
ikenna ogbodo says
Please sir, I need you to design me an inverter circuit with ac and solar charging units, switching with relays for effective battery capacity that can carry home appliances.
Swagatam says
ikenna, I have already published quite a few such designs in this website, please use the search box to find them and select as per your application needs