The post discusses a simple IR remote control circuit which can be used for controlling many appliances independently through a single transmitter handset. The idea employs ordinary components like IC LM567, IC 555 and does not incorporate microcontroller devices. The idea was requested by Mr. Saeed Abu and also other dedicated readers of this blog.

Technical Specifications

bro thanks for ur reply. Pls develop a simple Infrared (IR) Remote Transmitter/Receiver Circuit diagram.My requirement is:

1) It must be specified for its transmitter.No interference with Tv/Vcd remote or any other type of remote.

2) It(receiver) should be powered by Ac 220v.

3) It(receiver) can be used for multiple load(Light+Fan+..+..) by one transmitter

4) Please develop it very simple.

The Design

The following design depicts the basic IR receiver module using the IC LM567. The involved stages can be grasped with the help of the following points:

The IC LM567 which is a tone decoder IC or more simply a frequency decoder IC is rigged to produce a particular frequency determined by R3 and C2.

This frequency becomes the bandpass frequency of the circuit such that the circuit now gets locked on this frequency.

The input pin#3 of the IC is attached to a photodiode device for receiving an IR signal which may be tuned to the above set frequency of the IC.

This means that the circuit will now respond whenever D2 detects an IR frequency tuned to the frequency determined by R3/C2 of the configuration.

On detecting a coded frequency from a relevant transmitter the IC M567 output pin8 becomes low and stays in that position until the transmitting signal is prohibited.

Thus this circuit becomes the receiver module and may be triggered by a transmitter circuit tuned at the relevant fixed frequency.

The IC2 which is a Johnsons decoder divider IC is wired as a flip flop circuit, it's integrated to pin8 of the IC LM567

As long as no signal is detected by D2, pin8 of IC1 remains high, the moment a signal is detected, T3 is triggered, which in turn triggers pin14 of IC2.

The above situation prompts IC2 output to change state thereby either activating RL1 and the connected appliance or deactivating them depending upon its initial condition.

For controlling multiple gadgets using a single transmitter handset, many of the above modules may be constructed and integrated with the corresponding appliances for the intended switching.

Circuit Diagram

Controlling multiple appliances using the following single IR transmitter circuit

The following circuit forms the transmitter module of the proposed IR remote control for activating multiple gadgets.

It's a simple IC 555 astable circuit, whose output frequency is determined by the 5 individual capacitors and should be appropriately matched with the particular receiver circuit modules as discussed in the above section.

The capacitors attached with the respective buttons should be calculated and matched such that on pressing the relevant button, the corresponding receiver gets triggered for toggling the corresponding appliance.

R1, R2 may be chosen arbitrarily, but Cz must be selected in accordance with the receiver module frequency determined by R3 of the module.

Multiple Frequency Transmitter Circuit


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