THREE MELODY GENERATOR
Price - Stock
Listen to audio for the Three Melody Generator
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. Bend the legs of the resistor with long-nose pliers to match its holes and push it 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. Insert the IC socket. Be careful to ensure
all legs protrude through the holoes in the PCB. Solder all legs of the
4. Six PCB pins are located at the locations shown. Solder in place.
5. The 0.1uF capacitor can be inserted and
6. Identify the LED legs. It is polarised. There is a flat at the base of the globe. This is above the K leg, which is also the shorter leg. Insert the LED as the drawing shows. Solder in place.
7. The battery holder is connected to the PCB pins as
shown. Solder to the PCB pins.
8 Cut the fig. 8 wire into two appropriate lengths, one for the speaker, one for the switch. Strip the insulation approx 5 mm from each end. Tin the ends of the wire - See Tinning wire .
9. The Speaker has +ve and -ve terminals, use one length of fig 8 wire to connect the terminals to their respective PCB pins.
10. Use the second length of fig 8 wire to connect the switch to the chosen trigger.
11. You will find that the legs of the HK227 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.
11. Insert batteries and press the switch to test.
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.
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 directly to the speaker.
View the HK227 Datasheet
Contact CdS electronics