Low-cost Infrared Control Extender
Created: Sep 11, 2014
No description available.
This simple circuit features the modification of infrared controller that are commonly used by electronic home entertainment appliance. It extends the convenience of infrared controller brings to the user. It has high radiant sensitive and fast response time sensor compared to other infrared controller circuit.
The circuit is comprised of PIN photodiode that is connected to the inverting input of an operational amplifier through the 3.3kΩ resistor and 47nF capacitor in series. It also connected to the noninverting input through 100kΩ resistor R1 in which the supply voltage is divided by the two 100kΩ resistor. It also needs to be reverse-biased to turn light energy into a corresponding voltage. The output of the OP-AMP is fed to the BD240 transistor that is capable of supplying high current pulses through the LD274 IR LEDs. The current through the IR LEDs is limited by the resistors in series. The currents are in peak levels due to the small duty factor of the infrared radiation pulses and the current drawn from the battery is also small. The range of control extender may be increased by fitting the devices with reflective caps.
The design is applicable to an obstructed area and place where there are other sources of disturbances that can affect the infrared signal. It is suitable for wireless communication development.