The previous day my son said ” A friend has a mini organ. Casio SA-76 44 Key Mini Keyboard, Orange It is Good quality but expensive.
My son would have the same. But I said, as we are the Electronic inventor, to try to create their own. We are proud and cheaper too.
You might like this mini organ keyboard circuit certainly. Because in addition to the simple, the price is not expensive, effective really worthwhile.
You may consider the main features of the circuit, as follows.
1. Can works with DC voltage in rang 3-12 Volt by low current consumption.
2. There are the music playback up to 15 keys, or a note from G3-G5.
3. Can be programmed to play. Repeat for up to 47 notes.
4. Can act as a music source by up to 15 songs.(Simple carbohydrates. Press any key. To select the desired song.)
How circuit works
In the heart of the circuit is the UM3511
-IC is designed to act this purpose
-Internal IC consists of a lot. We do not need to explain the operation of the circuit Internal this IC. Our job only assembly equipment used in the first the circuit to be completed.
-From circuit in figure 1 will see that we can connect a output of pin 5 on the UM3511-IC to drive a transistor output to emit loud sound out to the speakers directly.
-For the variable resistor-VR1 act as determine a frequency of the oscillator circuit. When we created successfully. Should be adjusted to the correct value. When adjusted, you may use the normal resistor instead.
-The switch-S1 as an option act the work of circuit that music will be played by the application of the factory, or will play music as we have played own. From pushing keyboard as by various notes.
For a list of songs that can be programmed from the factory. Which will play out as We have push switch as follows.
G3 Hush little baby
A3 Twinkle Little Star
C4 Dream of Home and Mother
D4 Christmas Carol
E4 Are You Sleeping
F4 The Famer in the Dell
G4 In a Persian Market
A4 Mary Had a Little Lamp
B4 Long Long Ago
C5 Santa Lucia
D5 Little Brown Jug
F5 The Train is Running Fast
G5 Close Encounters of the Third Kind
How to build and setting
Suppose that you want to play Santa Lucia, it may be done as follows.
1. Hit the switch S1 to the program.
2. Press the C5 keyboard switch.
Only this time, it will play the music you want to finish it, it will stop automatically.
For convenience we have on the power supply is designed for the 5 volt dc regulator circuit. To be applied to the input voltage from 6 volt to 24 volt. It also allows the voltage to be smooth, no hum at play.
Figure 2 the pcb layout of a mini organ keyboard circuit using UM3511
All components except the transformer and speaker. We can assemble onto the PCB. As shown in Figure 2.
For keyboard switch because we want you to get a feel for the playing. As the organ of the fact that selling in the shop. We chose to use a computer key switches.