MULTI MELODY GENERATOR

INSTRUCTION SHEET

Price - Stock No 311

Listen to audio for Multi Melody Generator

This kit produces twelve melodies. A press-and-release action on the switch will play the next melody. If the switch is held closed, this kit will cycle through the entire playlist until the switch is released. You may consider customising this kit for example:

Replace the switch with a micro switch and use it as a musical jewelery box (the switch activates when the lid is opened)
Remove the switch and add hookup wire and teardrop terminal and use it as a musical Skill Toy (the next melody will play if the player fails).

1. AMERICAN PATROL
2. RABBITS

3. OH! MY DARLING CLEMENTINE

4. BUTTERFLY

5. LONDON BRIDGE IS FALLING DOWN

6. ROW, ROW, ROW YOUR BOAT

7. ARE YOU SLEEPING

8. HAPPY BIRTHDAY TO YOU

9. TOY SYMPHONY

10. HOME SWEET HOME

11. LULLABY

12. SHE WORE A YELLOW RIBBON

1. Check your P.C.Board carefully for damage to the tracks. A Circuit Tester or a multimeter will help check that there are no broken tracks.

2. Identify the resistors by their colour bands or with a multimeter. Bend the legs with long-nose pliers to match their holes and push them into place against the surface of the board. Remember that the drawing is looking at the PLAIN side with the tracks away from you. When in place, bend the legs sideways a bit to stop the resistors from falling out. Solder in place - see Soldering Technique

3. Use care when inserting the IC socket. Solder in place.

4. Identify the PCB pin locations, insert and solder.

5. The BC 548 must be inserted in the correct orientation. It has a flat on the body. Mount it with the flat as the drawings show. Care should be taken when soldering the transistors - excessive use of heat from the soldering iron may permanantly damage these components (a heatsink tool or long nose pliers will dissipate excessive heat).

6. Identify the LED legs A and K. Insert in the correct orientation and solder in place.

7. Solder the positive and negative leads of the battery holder to their respective pins.

8. Figure 8 wire is included to attach the speaker and switch away from the PCB. The switch can be mounted directly on the PCB if you choose. Cut the wire to appropriate lengths. Strip the ends of the wire and tin the bare ends - see Tinning wire .

9. Solder the switch to its appropriate PCB pins (or via figure 8 wire).

10. The speaker has a positive and negative terminals. Use the stripe on the wire to ensure the correct terminals are connected to the correct PCB pins.

11. You will find that the legs of the HK221 are spread a little wide to fit into their sockets. Take each IC and rest the legs on a flat surface. Gently push down so that row of legs is straightened a little. Repeat for the other row of legs. Take the IC and find the locating mark on the top surface and near or at one end. Check the drawing and push it into its socket the right way round.

12. Insert batteries and press the switch to test.

Trouble shooting

Troubleshooting if necessary will involve careful checking of locations and polarity of components. Re-solder all joints and check to make sure you have not bridged across between any two adjacent component legs. The end of a broken hacksaw blade sharpened on an emery wheel is a good tool for cleaning between soldered joints.

Technology Notes

The heart of this kit is the HK221 which is a purpose built Integrated Circuit for melody generation. The output of this IC is fed to the Base of the BC548 via the 1K resistor. The BC548 amplifies the sound for output by the speaker. See - Transistors

View the HK221 Datasheet

Contact CdS electronics

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