This is 2 watts + 2 watts Stereo small LM386 amplifier x3 ICs. It is cheap and easy to builds for BCL amplifier,mobile,MP3 player using 6V battery (AA x 4) [...]
See: 555 PWM DC LED dimmer circuit in 12V source. For a lot of loads even control the speed motor. Nearly with loss and high performance
SEE DIY compressor time delay circuit. Protect your compressor when power outage and Electrical fluctuations. Using normal parts and cheap.
These are four light sensor alarm circuits, when be become dark, or Light sensitive switch.Use part is important light sensor LDR light dependent resistor [...]
To Control speed DC motor easily with a few parts in circuit.
DC Switching Regulate 3A
TL084: low noise OP-AMP in cheap. Use JFET input. Why popular in audio & a lot of circuits: wide bandwidths and fast slew rates. Example: