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Mains Manager

Mains Manager Circuit diagram. Very often we forget to switch off the peripherals like monitor, scanner, and printer while switching off our PC. The problem is that there are separate power switches to turn the peripherals off. Normally, the peripherals are connected to a single of those four-way trailing sockets that are plugged into a single wall socket. If that socket is accessible, all the devices could be switched off from there and none of the equipment used will require any modification.  Here is a mains manager circuit that allows you to turn all the equipment on or off by just operating the switch on any one of the devices; for example, when you switch off your PC, the monitor as well as other equipment will get powered down automatically. You may choose the main equipment to control other gadgets.  The main equipment is to be directly plugged into the master socket, while all other equipment are to be connected via the slave socket. The mains supply from the wall soc...

Wireless mains voltage tester

Description . This circuit can be used to test whether mains voltage is present or not without having electric contact with mains line. The CMOS IC CD4033 is the heart of this circuit. The CD4033 consists of a 5 stage decade Johnson counter and an output decoder for converting the Johnson code to a 7 segment decoded output for driving 7 segment LED display . A 10cm long insulated copper wire connected to the clock pin (pin1) of the IC serves as the sensor. The sensor wire has to be placed in the vicinity of the mains wire to be tested. When there is no voltage in the mains line, no voltage will be induced in the sensor wire and the display will show a random digit. When there is voltage in the mains line, a small voltage will be induced in the sensor wire due to electromagnetic induction and this voltage is sufficient enough to clock the CMOS IC CD4033. Now the display will count from zero to nine and repeat. Circuit diagram. Notes. The circuit can be assembled on a Vero board. U...

AC Mains Bistable Switch

This AC mains-operated bistable  switch turns on or turns off a  device using a miniature neon  lamp and a few discrete components.  This switch can be used for control pan-els, appliances and lighting controls.  A push-to-on switch is used to  light up the neon lamp. The light emit-ted by the neon lamp, in turn, enables  the switching action of the circuit. Use  of a 555 timer wired for bistable operation makes the circuit act as a bistable  switch. Circuit diagram : AC Mains Bistable Switch Circuit Diagram   The neon lamp (NL1) and the  push-to-on switch (S1) are directly connected to 230V AC mains. The 12V DC  supply for timer 555 (IC1) is derived  from 230V AC mains through capacitive dropper C1, resistor R1 and a 12V  zener diode. IC1 works as a flip-flop  circuit, with the signal at its output  pin 3 toggling every time it receives a  pulse at its pins 2 and 6.  The operation of the circuit ...

Mains Slave Switcher II

Mains Slave Switcher II Circuit Diagram . As a guide, a one-inch reed switch with 40 turns reliably switched on with the current flowing through a 150-watt lamp (approx. 625 mA) but larger reeds may require more turns. If the master appliance draws less current (which is unlikely with power tools) more turns will be required. The reed switch is used to switch on transistor T1 which in turn switches the relay RE1 and powers the slave appliance. Since reed switches have a low mechanical inertia, they have little difficulty in following the fluctuations of the magnetic field due to the alternating current in the coil and this means that they will switch on and off at 100 Hz. Mains Slave Switcher II Circuit Diagram: Mains Slave Switcher II Circuit Diagram C3 is therefore fitted to slow down the transistor response and keep the relay energised during the mains zero crossings when the current drawn by the appliance falls to zero and the reed switch opens. C1 drops the mains voltage to about...

Low Voltage Remote Mains Switch

This circuit allows a 240V mains appliance to be controlled remotely via low-voltage cabling and a pushbutton switch. The mains appliance (in this case, a light bulb) is switched with a suitably-rated relay . All of the electronics is housed in an ABS box located in proximity to the appliance. The pushbutton switch and plugpack are located remotely and can be wired up with 3-core alarm cable or similar. Cable lengths of 20m or more are feasible with this arrangement. When the switch (S1) is pressed, the input (pin 8) of IC1c is briefly pulled low via the 10mF capacitor, which is initially discharged. Low-Voltage Remote Mains Switch Circuit diagram: Low-Voltage Remote Mains Switch Circuit Diagram The output (pin 10) immediately goes high and this is inverted and fed back to the second input (pin 9) via another gate in the quad NAND package (IC1d). In conjunction with the 1MW resistor and 470nF capacitor, IC1d eliminates the effects of contact "bounce" by ensuring that IC1c’s o...