This is a low pass filter subwoofer using IC 324 and some other components.
Do you love music? Imagine we can build power amplifiers system. Sound good, doesn’t it? Here are many circuits. For example, about Audio amplifiers, bridge amplifier, Using transistor or IC or MOSFET, Mixer, Graphic Equalizer, Preamplifiers. And, Sound generators, tone controls, Melodies, Sirens, Animal sound, effect voices. Even, Burglar alarm, and more. I cannot explain to you all. But sure I do not like to see you miss them.
This is Morning sun alarm circuit using IC-4011 that hobby It will have sound alarm when morning like a normal clock alarm with lighting sensor same clock.
This is LM383 Amplifier circuit 7W,suited for automotive or many car systems-14.4V,high current capability 3.5A. It is current limited,thermally protected
Today we see the 19W stereo integrated amplifier IC-TA7240AP, ideal for small rooms Or use the car because the power supply only 12 volts. [...]
The 2 tone doorbell circuit, which is an electronic buzzer types,but them has melodic sound than general electric bell. People have seen two tone bell sound
This is a sound effect generator circuit using small electronic components to generate since birds up to siren. With two IC-CMOS are main.
The Door Guard Knob Alarm circuit with touch system. When thief caught on door handle, makes alarm once. Use the the detector capacitance within the body.