Rain alarm is a simple circuit using water sensor (transducer) that produces an audible alarm whenever rain falls. The circuit can be based on two transistors and or a NE555 IC. The two transistors are wired as a switch which goes on when the base of Q1 is shorted to the positive of the supply [...]
skema+power+amp+cube
Especially designed for Christmas tree lampsReplaces old thermally-activated switches This circuit is intended as a reliable replacement to thermally-activated switches used for Christmas tree lamp-flashing. The device formed by Q1, Q2 and related resistors triggers the SCR. Timing is provided by R1, R2 & C1. To change flashing frequency do not modify R1 and R2 [...]
This car stereo booster uses an LM2896 IC which has two integrated amplifiers. It can be powered with voltages up to 15 volts. The power output is 2.5 watts per channel with an 8 Ω load and supply voltage of 12 volts. Using the bridge tehnique in the circuit gives a power output of 9 [...]
This simple metal detector requires alone a scattering of apparatus and an evening’s work. Congenital about a cmos4011 IC, is actual able-bodied and versatile. The 250 kHz advertence oscillator is congenital with two gates (U1/1 and U1/2), C1, R1 and P1. The chase oscillator uses alone one aboideau (U1/3), two capacitors and the chase coil. [...]
This Bat Detector Circuit is authored by Chris Eve. Basic tests with a variety of salvaged electret microphones all showed good response to 50kHz and beyond, the smaller the unit the better the response. My tests indicate that a small electret microphone has at least some response to 100kHz and that this response is reasonably [...]
