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Simple
Sensitive Remote Control Tester
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Here
is a handy gadget for test- ing of infrared (IR) based
re- mote control transmitters used for TVs and VCRs etc.
The IR signals from a remote control transmitter are sensed
by the IR sensor module in the tester and its output at
pin 2 goes low. This in turn switches on transistor T1
and causes LED1 to blink. At the same time, the buzzer
beeps at the same rate as the incoming signals from the
remote control transmitter. The pressing of different
buttons on the remote control will result in different
pulse rates which would change the rate at which the LED
blinks or the buzzer beeps. When no signal is sensed by
the sensor module, output pin 2 of the sensor goes high
and, as a result, transistor T1 switches off and hence
LED1 and buzzer BZ1 go off. This circuit requires 5V regulated
power supply which can be obtained from 9V eliminator
and connected to the circuit through a jack. Capacitor
C1 smoothes DC input while capacitor C2 suppresses any
sudden spikes appearing in the input supply. Here, a plastic
moulded sensor has been used so that it can easily stick
out from a cut in the metal box in which it is housed.
It requires less space. Proper grounding of the metal
case will ensure that the electromagnetic emissions which
are produced by tube-lights and electronic ballasts etc
(which lie within the bandwidth of receiver circuit) are
effectively grounded and do not interfere with the functioning
of the circuit. The proposed layout of the box containing
the circuit is shown in the figure. The 9-volt DC supply
from the eliminator can be fed into the jack using a banana-type
plug.
Tech. Editor’s note: In fact, the complete gadget can
be assembled in the eliminator’s housing itself and a
cut can be made in its body for exposing the IR module’s
sensor part. |
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