From this 20watt Integrated Amplifier project. Some people say that expensive and want the main amplifier only. I recommend this project, it had a budget of only 5$. and is the main amplifier. They have size of power to speaker is 40 watts and use voltage of power supply is 12 volts so can apply right in car. They use the HA13001-IC is key parts so small and build easily.
How This Circuit works
When see a circuit as Figure 1 Many people would doubt that. This circuit will be amplified up to 40 watts. (If as the RMS will is about 17.5 watts at load 4 ohms). You do not insult it because the many circuits that were contained in IC1-HA13001 of Hitachi there. Makes a few external devices, and the output of IC1 that connects to the loud speaker will be connected on the bridge circuit types. So causes the output has a high power there.
We do not fear that the speaker will be damaged easily. because in IC1 has the Automatic Shut-Off circuit (ASO) that use to protect the speaker. Thus You need to carefree it. and this circuit will use the power supply range between about 12-18 volts for its’ source.
How to builds this projects
This simple project starting with make the PCB which has copper layout as figure 2 before. Then solder all components as figure 3. We can solder directly the IC1 onto PCB so should take special care.
The power supply that can use a DC adapter but must provide current over up 1 amperes. Otherwise, when you accelerate the more volume, the sound will be broken and Adapter will malfunction.
The application this projects
This amplifier project use to amplify from the various sound generator such as The iPad or mobile phone or notebook computer’s etc. Or Modified into the old car stereo that repair difficult. We changed the set to the amplifier.
The detial parts.
The electrolytic capacitors 16 volts
C4, C5, C7, C8_______100uF
The ceramic capacitors 50V
C3, C9, C10__________0.1uF
¼ W + 5% Resistors
R2, R3_______________2.2 ohms
Speaker 20 W 4 ohms
Heat sink for IC1