http://www.electroniccircuit.biz Simple Electronic Circuit Designs and Schematics, Hobby kits. Tue, 05 Jan 2010 00:05:05 +0000 http://backend.userland.com/rss092 en The circuit presented here wakes you up with a loud alarm at the break of the daylight. Once again the 555 timer is used here. It is working as an astable multivibrator at a frequency of about 1kHz. The circuit's operation can be explained as follows: When no light falls on the ... http://www.electroniccircuit.biz/alarm/daylight-alarm-circuit-diagram.html This circuit warns the user against fire accidents. It relies on the smoke that is produced in the event of a fire. When this smoke passes between a bulb and an LDR, the amount of light falling on the LDR decreases. This causes the resistance of LDR to increase and ... http://www.electroniccircuit.biz/alarm/fire-alarm-circuit-diagram.html Flash slaves are used when you need to supplement one flash unit with one or several more. This slave trigger simply triggers those other units. It does this by "seeing" the first flash (using a phototransistor) and triggering the other flashes a few microseconds later. The sensitivity of the circuit ... http://www.electroniccircuit.biz/light/flash-slave-trigger-circuit.html Amplifier parts: P1_____________22K  Log. Potentiometer (Dual-gang for stereo) R1______________1K  1/4W Resistor R2______________4K7 1/4W Resistor R3____________100R  1/4W Resistor R4______________4K7 1/4W Resistor R5_____________82K  1/4W Resistor R6_____________10R  1/2W Resistor R7_______________R22  4W Resistor (wirewound) R8______________1K  1/2W Trimmer Cermet (optional) C1____________470nF  63V Polyester Capacitor C2,C5_________100µF   3V Tantalum bead Capacitors C3,C4_________470µF  25V Electrolytic Capacitors C6____________100nF  63V Polyester Capacitor D1___________1N4148  75V 150mA Diode IC1________TLE2141C  Low noise, high voltage, high slew-rate Op-amp Q1____________BC182  50V ... http://www.electroniccircuit.biz/audio/18-watt-amplifier-circuit.html This circuit adds a power down function to analog I/O ports (for example, the AD7769 and AD7774). Moreover, the diodes ordinarily needed to protect the devices against power-supply missequencing can be eliminated In the circuit, MOSFETs Q1 and Q2 switch the +5- and +12-V supplies, respectively, in a sequence controlled by two ... http://www.electroniccircuit.biz/power/simple-power-down-circuit.html