Parts List:
| R1-2-4-5=270Ω R3 = 2.7Ω VR1 = 10KΩ Log. Pot. TR1 = 470KΩ Trimmer IC1-2 = LM388 |
C1 = 100uF/25V C2 = 100nF C3 = 10uF/25V C4-5 = 22uF/25V C6 = 47nF |
This is the 4W bridge amplifier circuit design based on power IC LM388 as the main component. Currently there are 2 chips of LM388 used since a LM388 only have one channel amplification. A single LM388 will deliver about 1.5W power audio output, while 2 pieces of it used with bridge connection, ten it will deliver up to 4W power audio output.
Notes:
For 6V supply and 4Ω loudspeaker, the circuit will deliver 1W audio output.
For 12V supply and 8Ω loudspeaker, the circuit will deliver 4W audio output.
Download LM388 datasheet for your 4W bridge amplifier reference:
» Download link