If you plan to build this circuit, beware that you may have lots of difficulties though the schematic may seem simple. The construction of the circit requires some amount of equipment like an oscilloscope and a DVM, too. Without them, the device will do weird things you wouldn`t expect, and even if it is correctly put together, you must adjust it with care both mechanically in its final place and electronically with the help of an oscilloscope. Only if you want to span.....
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...
Although the concept of a totally accessible system represents an ideal situation for users, designers now must limit access toand conceal code sequences forsoftware routines for calibration, diagnostics, memory erasure, system reset, and more. In a system that includes a computer-compatible interface, such as an RS-232, a GPIB, or an infrared-I/O port, the system`s software can detect unique input patterns and execute the "secret" code sequences...
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.....
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.....
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.....
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. IR transmitter uses two-stage transistor.....
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...
This simple circuit allows you to record any IR remote control signal on your PC, and then play it back. This is particularly useful if you want to control appliances such as TVs, VCRs, CDs etc. from your computer. The device simply connects to the parallel port of your PC. You can also use this circuit to analyze the waveform from any IR remote control. The circuit consists of two parts. The first part is the IR receiver made up of a OP-505 IR photo transistor. This.....
This unit uses one TSAL6100 IR/LED emitter from Digi-Key. This IR diode has a narrow (10 degree) radiation pattern at 940 NM. It is driven via 2n2904 transistor for maximum current pulses. The detector is a Vishay TSOP4838 38Khz integrated receiver module. The 38Khz signal for the emitter is generated in software. Here is the idea: Send out a 38Khz IR signal and look for its reflection off a nearby object. Both the emitter and detector are optically and electrically.....
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 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...
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:..
Senses heart pulse by means of an infrared earlobe clip. Reverse engineered circuit diagram of heart pulse sensor circuit board out of a treadmill. Notice that the output is level shifted for use by CMOS logic running on 4.5V regulated down from the 6V battery. The CMOS logic also controlls the power to the analog circuitry and infrared LED...
The current concept incorporates a wireless transmitter and receiver and is thought to be used for remote controlled airplanes or appliances with two seperate parts. In other words, we have one dedicated transmitter (acquisition, filtering) and one dedicated receiver part (user-interface, look-up table, calibration, storage), capable of being connected together with any physical layer, e.g. wired, wireless, infrared. If you want to build a standalone altimeter/variometer.....
A rangefinder is described that uses the propagation time of a beam of infrared radiation to measure distances of up to 120 meters with errors of less than 50 µm. The instrument is capable of measuring up to five different distances per second by directing an amplitude modulated infrared beam to a retroreflector located at the far end of each path. The instrument is being tested with the expectation that such a system could be used to make precise and rapid measurements.....
This circuit features automatic Exit/Entry delays, timed Bell Cut-off and System Reset. It has provision for normally open and normally closed switches and will accommodate the usual input devices such as Foil Tape, Pressure Mats, Magnetic Reed Contacts, Passive Infrared Detectors and Inertia (Shock) Sensors...
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...
The transmitter is shown and although straightforward, there are a couple of tricks that I had to incorporate to minimise battery drain during standby. Although the PIC quiescent current is only 200uA, that will still flatten a pair of AA or AAA 1.5V cells over time. The receiver provides motor drive (forward and reverse) for the motorised pot, and a relay for muting. The relay simply shorts out the preamp's output - this will not cause any damage to the preamp, as long as.....
Operational Amplifiers
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ANSI Standards
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