How to build a Infrared Remote Control Security Lock Circuit for Automotive Applications

An easy, low-cost yet very beneficial infrared based remote controlled security lock could be researched in the following post.

Infrared Remote Control Security Lock Circuit for Automotive Applications


Infrared Remote Control Security Lock Circuit for Automotive Applications

The LM567 IC is truly one of my favorites mainly because it’s too extremely versatile, and evolves into appropriate in the majority of of the critical circuit principles by way of hassle free configurations.

One such critical yet effortless IR remote control receiver application can be watched in the above diagram, which stimulates simply by way of a unique established frequency as set by R1/C1 in the circuit.

The above theory can be employed in automotive security programs for locking the ignition with the aid of a specifically set frequency code.

In the established circuit R1/C1 establishes the latching frequency of the unit, which might be measured employing the following formula:

f = 1/R1C1, which constitutes to be 100kHz for the presented values of R1, C1.

Pin3 that may be the receptor pinout of the IC is designed with a IR diode for acquiring an incoming tone locked frequency set at the matching 100kHz frequency.

Any time these kinds of a similar frequency is noticed at pin3 of the IC, pin8 reacts and evolves into low momentarily activating the transistor latch.

The transistor and relay latch all together to accept the result and open the locked ignition for the user.

Almost every other frequency which often can not coincide with the set R1/C1 value is definitely eliminated by the IC preserving the ignition properly secured and locked, therefore the system evolves into particularly dependable and protected from potential bike thieves.

pin1 output from the IC could be connected with an audio amplifier and buzzer just in case an audio signal is sensed vital in the course of the remote control activation.

But yet this really need the transmitter to be combined with a modulated audio signal over the carrier base frequency.

A relatively easy complementing IR remote handset circuit could be noticed below:

Infrared (IR) Remote Control Security Lock Transmitter Circuit


Infrared (IR) Remote Control Security Lock Transmitter Circuit

It is usually an easy two transistor R/C based oscillator, whose frequency varies according to the proved R and C values and coincidentally here too the formula resembles its Rx counterpart, that could be:

f = 1/RC

As a result the Tx circuit frequency evolves into less difficult to determine and match with the LM567 receiver circuit talked about in the prior section.

For triggering the Rx circuit, the above Tx circuit IR diode emission merely should also be concentrated on the IR receiver diode of the Rx unit. This instantaneously unlocks the Rx circuit for the designed results.

The design can be employed for locking a multitude of other security devices which need to have a simple specifically coded locking functions.