Remote operated musical bell using UM3481

This article is about remote operated musical bell using UM3481. The M348X series IC is a mask-ROM-programmed multi melody generator , implemented by CMOS technology. It is designed to play the melody according to the previously programmed information and is capable of generating 16 songs with 3 instrument effects : piano, organ and mandolin. The device also includes a pre-amplifier which provides a simple interface to  the driver circuit. The M3481 series is intended for applications such as toys, door bells, music box, melody clock/timers and telephones. The following circuit is infrared controlled musical bell. You can use any kind of remote control, for example, TV, DVD player remote control, etc. It can be switched from a distance of 5-10 meters provided that the remote control is directed towards the sensor. It uses TSOP1738 infrared sensor that triggers music built inside the UM3481 IC. You can use UM3482 and UM3483 that produce 12 and 5 melodies respectively. The sensor responds to 38Khz and it can be activated by any key of the remote control. CLICK HERE: How to test UM3481   When you press the remote key the output pin of TSOP1738 goes low. Transistor Q1 then conducts to trigger the UM3481 at pin 4. After playing a music melody, it automatically stops. If you press the remote again, the IC plays another melody. In this way, you can play 8 melodies one after another. The melody will repeat if pin 5 is connected to +6V(Pin 16) and will stop automatically if connected to GND(Pin 8). I recommend you to go through the datasheet of UM3481 to know more about it. Click on the video below to see the output and process for making the circuit. You can watch the process in the following video TSOP1738 UM3481  (8 songs)