Quartz crystal based remote thermometer features direct Celsius readout:  03/17/05 EDN Design Ideas  / (added 5/05)  Although quartz crystals have served as temperature sensors, designers haven't taken advantage of the technology because few manufacturers offer the sensors as standard products (references 1 and 2). In contrast to conventional resistance- or semiconductor-based sensors, a quartz-based sensor provides inherently digital-signal conditioning, good stability, and a direct digital ou...

Radio Remote Control using DTMF #2:  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.... (added 09/05)

RC5 IR Remote Control Transmitter:  In this application note the widely used RC5 coding scheme from Philips will be described and a fully working remote control solution will be presented. This application will use the ATtiny28 AVR microcontroller for this purpose  (circuit design added 3/05)

RCM710 Electronic Scale:  (Electronic Schematic / circuit added 4/02)

RD68HC908IRC : MC68HC908QT2 Based Simple Infrared Remote Control Reference Design:  Motorola has developed a simple, single dedicated device, infrared remote control designed to control a DVD player. This reference design demonstrates how to time and create modulated infrared signals used to control six basic functions of the DVD player.  (Circuit / schematic design added 6/06)

Receiving Remote Control Signal using Externally Triggered Timer:  Toshiba 870X Series Application Note  (Circuit / schematic design added 6/06)

Remote Charging Circuit uses Three Wire Sensing:  05/25/95 EDN Design Ideas / (added 05/02) - Remote voltage sensing usually uses a four wire sensing System, this System works with three Wires

Remote Control Encoder/decoder with PIC16C620 and PIC12C508:  (Circuit / schematic design added 6/06)

Remote Control for Sony a /  Volt Equipment:  PIC based remote controller for Infrared and wired Control-S bus (Electronic Schematic / circuit added 4/02)

Remote Control turns Battery on and Off:  09/12/97 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)  

Remote Control using Telephone:  Here is a tele-remote circuit which enables switching "on" and "off" of appliances through Telephone lines. The circuit described here can be used to switch up to nine appliances (corresponding to the digits1 through 9 of DTMF the Telephone key-pad). The Telephone can be used to switch on or switch off the appliances also while being used for normal conversation. FAIR WARNING -- THIS SITE HAS ANNOYING POP UP ADS. (Electronic circuit added 4/05)

Remote Control:  This is a simple wireless remote control unit, which was originally designed for a model hovercraft which I was developing with the help of my friend Uday Arya. The project has been discontinued for technical reasons, but this remote control unit survives. The method used seems to be quite popular among many remote control units. (Circuit / schematic design added 6/06)

Remote digital thermometer sends data over AC Power line:  (Electronic circuit added 4/05)

Remote Doorbell Indicator:  (Electronic Schematic / circuit added 4/02)

Remote Doorbell Warning Switch:  This circuit should only be used with the solenoid type chime doorbells, the electronic type that play tunes will not work here. The hardest part for this circuit was the title. It is quite easy to miss the sound of a doorbell if you are watching TV , this circuit gets round the problem by providing a visual indication, i.e. a lamp. As an alternative, a LED could also be used. You could just parallel a lamp across the doorbell, but this would mean extra drain from the doorbell batteries or transformer. (added 2/06)

Remote Field Strength Meter:  (Circuit / schematic design added 6/06)

Remote humidity sensor needs no Battery:  04/04/02 EDN Design Ideas  /  (added 1/05)  Using ac-line power sources and batteries for remote humidity sensors is undesirable because these sources can be troublesome if you mount them in inaccessible points, such as smokestacks, cold-storage chambers, or darkrooms, where maintenance is difficult and inconvenient. Figure 1 shows a simple way to remove the power source from the humidity-sensor circuit. ...

Remote Keyless Entry and Convenience Center Reference Design with LIN Bus Interface:  Microchip Application Note - Published 26-Sep-02   (Circuit / schematic design added 6/06)

Remote Monitoring System Sends E-mail via SMS:  App Note 3297: Maxim IC  (Circuit / schematic design added 6/06)

Remote Solar LED Light:  (added 8/03)

Remote Switch uses No Power Fiber Optic Link:  10/10/96 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)  

Remote temp Sensor Needs No Power Supply:  12/21/95 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

Remote-Operated Musical Bell:  (Electronic Circuit / Schematic added 10/04)

RF remote Control Based on Basic Stamp:  (Circuit / schematic design added 6/06)

RF Remote Control System:  (Electronic Schematic / circuit added 4/02)

Rolling code 4-channel UHF remote Control:  (Electronic circuit added 4/05)

RS-232c Serial Port Scans Remote Keypad:  12/04/97 EDN-Design Ideas / (Circuit / schematic design added 6/06)