Infrared

This 1 channel infrared transmitter/receiver remote control is the cheapest and simplest you can find. The transmitter transmits a sequence of pulses on 36 KHz frequency carrier. The diodes are Schottky type because of their low voltage drop (only 0.2V).

A high performance op-amp that sets a new standard of excellence in noise performance only 0.9nV/Hz with low source resistances. Total harmonic distortion is less than 0.01%. The op-amp is suitable for use in high quality audio, low noise frequency synthesizers, infrared detectors etc. particularly where the source resistance is under 1Kohm.

I just finished a half duplex serial asynchronous link from a simple PIC circuit to the RCX. It is able to receive codes from the RCX (or Lego RCX remote control) store them in RAM & EEPROM and transmit any IR op-code to the RCX in turn. Included in the firmware is a routine that takes any opcode(s) and expand it to the proper IR packet for transmission to the RCX. I've used the UIRT circuit with a few modifications for the hardware. The UIRT includes a serial port programmer for the PIC16F84A so you won't need a separate programmer.

The following is a method to allow day and night detection using Infrared/Visible light sensitive phototransistors and a simple LM339 voltage comparator circuit. A phototransistor is mounted between the rails so that it is covered by the train as it passes. A system widely used in model railroading. For daytime operation the room lights would be on and when the train blocks this light the train is detected. However when the room lights are dimmed or turned off for night operation, under normal conditions the phototransistor would go dark and act as if it was covered by a train and give a false detection.

The goal of this project was to use infrared technology to remotely control a CD-ROM drive with an audio CD. The idea was developed by Matt Treiber in an attempt to make it more convenient to play audio CDs on his computer. This device will permit the basic functions of the CD player application such as play, next track, previous track, seek-forward, seek-reverse, and stop to be remotely controlled. The device will consist of an infrared detector and demodulator and the rest of the project will be implemented in the software.

The nitrogen laser will give 100kW pulses of light at 337.1nm (UVA light). The pulses are only 6ns long, so the energy per pulse is just 0.6mJ. It is a very simple laser, and it does not require mirrors or glass working at all! But using a mirror at one end of the laser will boost the output to over 250%. And if the nitrogen entering the laser (it is a flowing gas laser, but it can be made sealed) is cooled, it can go up to 120 pps. So if it is running at 120 pps, and has a mirror at one end, the average power output will be 180 mW. Although the beam is invisible it can be used to pump dye lasers to give beams with wavelengths ranging from infrared to ultraviolet.

Low frequency magnetic communications (LFMC) is a viable ?wireless? communications alternative to traditional radio frequency (RF) or Infrared communications. It is well suited for certain applications when considering some of the characteristics of the topology. Some of the main advantages of using low frequency magnetic communications are.

This is a general purpose remote control project with using programmable PIC microcontrollers. Schematics are shown for using infrared (RF) or radio (RF) media. If you are not familiar with microcontroller programming, you can use fixed encoder and decoder integrated circuits instead. Well-known such IC-s are Holtek HT-12D, HT-12E and Motorola MC145026, MC145027, MC145028. Remote controls usually consist of encoder/decoder parts connected to a transmitter /receiver module which takes care of the transmission of digital signals by radio or infra waves. The format of this project's signal is designed to be ideal even for the cheapest ASK RF modules (using 50% signal/silence ratio), and it is similar to the Philips RC-5 format used in infrared remote controls. The transmitter has a varying number of buttons and sends the states of these inputs to the receiver. The receiver device decodes the message and sets the outputs accordingly.

This is an image schematic or no description available.

Here is a circuit of a remote control unit which makes use of the radio frequency signals to control various electrical appliances. This remote control unit has 4 channels which can be easily extended to 12. This circuit differs from similar circuits in view of its simplicity and a totally different concept of generating the control signals. Usually remote control circuits make use of infrared light to transmit control signals. Their use is thus limited to a very confined area and line-of-sight. However, this circuit makes use of radio frequency to transmit the control signals and hence it can be used for control from almost anywhere in the house. Here we make use of DTMF (dual-tone multi frequency) signals (used in telephones to dial the digits) as the control codes. The DTMF tones are used for frequency modulation of the carrier. At the receiver unit, these frequency modulated signals are intercepted to obtain DTMF tones at the speaker terminals.

This is a programmable infrared (remote control) transmitter, which can be controlled from a PC serial port. It is capable of sending many remote control formats, including the Philips RC-5 standard. Exact formats with the timing parameter names are shown on the pictures:

This is a simple, cheap device that can be connected to any serial port to control most components that have infrared remote controls. I designed and built it (on a solderless breadboard) in 1991. In 1992 I wrote a lengthy description of it for an electronics class. In 1994 I finally designed a PC board for it, using a free, X-based PC board design program called pcb, and in 1995 I etched several of the boards and made the final product.

The need for ever increasing data rates required by a vast array of devices, such as notebook computers, printers, mobile phones, pagers and modems, has been satisfied by the technology of infrared data transmission. The Infrared Data Association (IrDA®) standard, which covers data rates from 2400bps to 4Mbps, is the overwhelming choice for infrared data transmission.

This circuit is designed for detecting infrared light modulated at around 40KHz. It’s feedback scheme cancels much of the DC component from ambient light. It’s conversion factor is about 100 millivolts per microwatt of 900nm light.

This circuit is designed to test visible and infrared LEDs in pulsed mode operations. It can drive the LED with peak currents in excess of 10 amps. A light detector nearby can monitor the response time and intensity of the LED under test.

These circuits were taken from a few application notes on infrared remote control devices. They use a current compensation method to separate the modulated light pulses from ambient light. They appear to have limited bandwidth and may only work at the 30KHz to 50KHz frequencies often used by TV and VCR remotes. I have not yet tested the circuits.

This circuit uses a large 1cm X 1cm silicon PIN photo diode and a transimpedance amplifier to measure the light power output of infrared and visible LEDs and laser diodes. It can be modified to produce almost any milliwatts to volts scale factor. It can be connected to either a multi-meter or an oscilloscope.

Using this low-cost project one can reproduce audio from TV without disturbing others. It does not use any wire connection between TV and headphones. In place of a pair of wires, it uses invisible infrared light to transmit audio signals from TV to headphones. Without using any lens, a range of up to 6 metres is possible. Range can be extended by using lenses and reflectors with IR sensors comprising transmitters and receivers.

The CIR, Computerized Infrared Remote, is a very simple device for recording and playing back streams of infrared data, in particuliar the codes transmitted via remote controls. It consists of two sections: a receiver to capture an incoming IR data stream, and one or more transmitters to resend the data stream under computer control.

The CIRThis article will show you how to build your own version of the Fire-Stick infrared remote control system. The Fire-Stick has been an extremely popular, and HOT selling item here at Rentron.com for quite a long time. The LITEON infrared receiver modules originally designed-in to the Fire-Stick have been discontinued, and forced us to re-design the original circuit boards.