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Here is a versatile remote controlled appliance switch that can ON or OFF any appliance connected to it using a TV remote. IR remote sensor IC TSOP 1738 is used for recieving the signal. Normally when no signal is falling on IC3 the output of it will be high.This makes Q1 OFF.When a signal of 38 KHz from the TV remote falls on the IC3 its output goes low.This makes Q1 conduct and a negative pulse is obtained at pin 2 of IC 1 NE 555.Due to this IC1 wired as a monostable multivibrator produces a 4 Sec long high signal at its out put.This high out put is the clock for IC 2 which is wired as a Flipflop and of , its two outputs pin 3 goes low and pin 2 goes high.The high output at pin 2 is amplified to drive the relay .For the next signal the outputs of IC2 toggles state. Result, we get a relay toggling on each press on the remote.Any appliance connected to this circuit can be switched ON or OFF. Circuit Diagram Notes. Before wiring the circuit make sure that the carrier frequency of the...

This code lock is useful for appliances requiring exclusive or authorised use by those who know the preset code. If desired, the code can be changed. The circuit doesn’t require additional AND or NOT gate operations at the outputs. It uses two pairs of 4-way DIP switches. The code is set using DIP switches DIP3 and DIP4. Then these two switches are hidden inside the assembly. With DIP3 and DIP4, up to 256 code combinations are possible. The unlocking code is set by the user using DIP switches DIP1 and DIP2, which is compared with the preset code entered earlier via DIP3 and DIP4. If the two codes match, transistor T1 conducts. 8-Digit Code Lock for Appliance Switching Circuit Diagram   The codes are compared using two cascaded 4-bit magnitude comparator Ics (IC1 and IC2). If the input nibble present at DIP1 matches with preset DIP3 nibble, output pin 6 of IC1 (connected to input pin 3 of IC2) goes high. Now if nibble present at DIP2 matches with the preset nibble at DIP4, pin 6 of ...

This is my first post and and this is the first circuit i made. There are many types of circuits for controlling home appliances using TV Remote. In fact I had confused a lot when I am a beginner searching for this type of circuits. The circuit here 555 timer IC to avoid fast switching. you can only switch the circuit after 3 seconds. IR remote sensor IC TSOP 1738 is used for recieving the signal. Normally when no signal is falling on IC3 the output of it will be high.This makes Q1 OFF.When a signal of 38 KHz from the TV remote falls on the IC3 its output goes low.This makes Q1 conduct and a negative pulse is obtained at pin 2 of IC 1 NE 555.Due to this IC1 wired as a monostable multivibrator produces a 4 Sec long high signal at its out put. This high out put is the clock for IC 2 which is wired as a Flipflop and of , its two outputs pin 3 goes low and pin 2 goes high.The high output at pin 2 is amplified to drive the relay .For the next signal the outputs of IC2 toggles state. Result...

Many of our costly appliances require three-phase AC supply for operation. Failure of any of the phases makes the appliance prone to erratic functioning and may even lead to failure. Hence it is of paramount importance to monitor the availability of the three-phase supply and switch off the appliance in the event of failure of one or two phases. The power to the appliance should resume with the availability of all phases of the supply with certain time delay in order to avoid surges and momentary fluctuations. The complete circuit of a threephase appliance protector is described here. It requires three-phase supply, three 12V relays and a timer IC NE555 along with 230V coil contactor having four poles. Relays RL1 and RL2 act as a sensing devices for phases Y and B, respectively. These relays are connected such that each acts as an enabling device for the subsequent relay. Therefore the combination of the relays forms a logical AND gate connected serially. The availability of phase R en...