This is fun project for small Christmas Music Box Circuit using IC UM66, also this UM66 chip already has melody inside.
When power is ON, it plays Christmas notes; moreover, this circuit is good for greeting cards, toys and mini gifts.
Circuit Working:
Parts List:
| Components | Values | Quantity |
|---|---|---|
| Resistor | 4.7k 1/4 watt | 1 |
| Capacitor | Electrolytic 1uF 25V | 1 |
| Semiconductors | IC UM66 | 1 |
| Transistor BC547 | 1 | |
| Speaker 4 to 8 ohms | 1 | |
| Battery 3V | 1 |
Main brain of this circuit is IC UM66 and this UM66 makes melody when power is ON; also its output is weak, so transistor makes it strong.
After that, transistor drives the small speaker and resistor controls base current, capacitor keeps supply smooth and finally, speaker plays the Christmas tune.
The following list shows the Christmas melodies commonly found in the UM66T-XX series melody ICs:
UM66T19 – Jingle Bells
UM66T20 – We Wish You a Merry Christmas
UM66T21 – Silent Night
UM66T22 – Santa Claus Is Coming to Town
UM66T23 – Joy to the World
UM66T24 – O Christmas Tree
UM66T25 – Rudolph the Red-Nosed Reindeer
UM66T26 – Little Town of Bethlehem
UM66T27 – O Come All Ye Faithful
UM66T28 – The First Noel
Note:
Different manufacturers sometimes use slightly different tune numbers, but the above list represents the most widely used set for the Christmas UM66T series.
How to Build:
Below are the steps to build a Christmas Music Box Circuit using IC UM66:
- First, collect all parts shown in circuit above.
- Next, pin 3 goes to transistor base through resistor R1.
- Then pin 2 of UM66 goes to 3V positive.
- Now pin 1 goes to ground.
- Also, emitter of transistor goes to ground.
- Further, speaker one side goes to transistor collector and other side of speaker goes to positive.
- After that, C1 capacitor goes between positive and ground and then add switch in battery line for ON and OFF.
Conclusion:
This Christmas Music Box Circuit using IC UM66 is a simple and fun project, as it uses very few components and plays a Christmas melody when we apply power.
Also, beginners can easily build this circuit and use it in greeting cards, toys, and small decoration projects.