Remote Control via GSM Mobile Phone Velleman’s MK160 remote control acts as a mobile phone activated relay to turn on lighting, heating, open a gate, simulate presence, or activate an alarm. The remote control works by sensing the backlight on mobile phones that light when a call is being received (activated spare cell phone required and sold separately)….

Telephone operated DTMF remote by KT3170 The circuit given below is of a telephone operated DTMF remote. The circuit can be used to switch up to 9 devices using the keys 0 to 9 of the telephone. Digit 0 is used to switch the telephone system between remote switching mode and normal conversation mode. IC KT3170 (DTMF to BCD decoder) is used to decode the DTMF signals transmitted over the telephone line to corresponding BCD format….

Electronic Touch Switch Mechanical contacts have the disadvantage that they wear out. That is why it is practical to use an electronic ‘touch switch’ in some situations. With such a touch switch the resistance of the human skin is used for the switching action….

Bounceless switch using IC NE555 This is circuit Bounceless Switch ,Use IC 555 Timer for Easy Timer circuit. Output pin 3 pluse 0.1s. Control by push S1……

One Button On Off Switch by 4093 and IRFZ44 The load is driven by the MOSFET IRFZ44 and 4093 AND gates are used in the circuit. The output of the 4093 IC drives the MOSFET. Only one button allows you to change the on-off state of the electronic circuits in which you use this switch. …..

Relay Timer switch By IC 555 and 741 In Fig.1 see a 100 second delayed turn ON relay RL1 switch, if plug power +12V in circuit. In Fig.2 see a two range 6-60 second and 1-10 minute auto turn off relay timer circuit, with 555. ….

On Off Touch Switch Circuit The modern mechanic switches are improved concerning of old technology. We need however many times to replacement some old switch or to check currents bigger than the durability of certain switches or simple we need something with modern appearance. ….

Touch Switch low cost by Timer IC 555 This Touch Switch circuit use a part compares with voltage 2 group , within the integrated circuit timer LM555 or NE555. For perform wait for catch the change of voltage , which be born from way leakage touches by change a finger. …..

Transistor intercom circuit Here is a simple but effective intercom circuit that is based fully on transistors.The circuit is based on a three stage RC coupled amplifier. When the pushbutton S2 is pressed, …

Mini intercom by one ic op-amp This is mini size intercom circuit. It uses IC Op-amp number LM380 just one as a result can work already. When switch S1 stay in a position speaks loud show in circuit picture….

Doorphone Intercom by IC LM386 For the first time, this circuit was designed by two authors, Mr Laurier Gendron of Burnaby in British Columbia, Canada, and myself. Please make sure you visit Laurier’s web site, Handy Dandy Little Circuits. This page is also available in French by clicking on the flag…..

LM390 MiNi Intercom Here is Intercom circuit,It Very easy Circuit. Use IC LM390 for Amplifier Sound Form Speaker or Mic.
Control S1a change Talk and Listen…..

Wireless Protable Intercom Voice Activated Chamberlain wireless portable inte- Provides convenient and expandablemunication for your home- Advanced features include voice activation and monitor mode- Crystal clear secure 900 MHz …..

Long range FM transmitter The power output of most of these circuits are very low because no power amplifier stages were incorporated….

Single chip FM transmitter circuit using MAX2606 Here’s a single chip FM transmitter circuit using Maxim semiconductors IC MAX2606. The MAX2606 is a compact, high-performance intermediate frequency VCO specially designed for wireless communication circuits. …

BA1404 HI-FI Stereo FM Transmitter Whether you want to create your own radio station, transmit the music around the house, or simply create a wireless link between your iPod and a receiver in your car, this transmitter will let you do these things easily…..

2 Transistor (BC548) FM Voice Transmitter Take care with transmitter circuits. It is illegal in most countries to operate radio transmitters without a license. Although only low power this circuit may be tuned to operate over the range 87-108MHz with a range of 20 or 30 metres. ….

BH1417 Stereo PLL FM Transmitter

High Quality 200mW FM Transmitter by BF199 Here is the latest and greatly improved TX200 VFO/VCO FM transmitter. The most versatile transmitter to date that can be turned into high fidelity stereo PLL based 200mW FM transmitter….

Car Burglar Alarm system with radio wave signal When steal open automobile door relay K1 and K2 work make have voltage 12V give radio transmitter and origin sound part for mix radio waves steal will deaf anything sound. Because radio high frequency. ….

Car Burglar Alarm timer delay using NE556 Car Burglar Alarm timer alarm system circuit , model to economize. This circuit convenients for to set up in an automobile. usually switch at set up keep with automobile door will the circuit closes. But in case of car owner opens in and out while note as a result have no result anything ….

Car Alarm Simulator When a car thief scoping out prospective targets sometimes is the nature of the alarm system will deter them … and definitely a heck of much cheaper than real thing! This stylish set that you can put your own “dummy” awaken together to save some cash and own your car may be in the process! ….

Complete Wireless Alarm System This kit comes with a complete wireless security system that can be installed in minutes. With the motion sensor and two door/window sensors, the system covers enough for a decent size house and with all the additional accessories and sensors….

Halogen Lamp Dimmer With Soft Start Most dimmers use pulse width modulation (PWM) to control the amount of power that is delivered to the lamp. Those that come bundled with a switch faceplate control the firing angle of a Triac on the 240V mains side. These work fine with resistive loads but may not be suitable for inductive loads such as low-voltage halogen lamp transformers. ….

Dimmer With A MOSFET BUZ41A This circuit shows that dimmers intended for use at mains voltage do not always have to contain a triac. Here, a MOSFET (BUZ41A, 500 V/4.5A) in a diode bridge is used to control the voltage across an incandescent bulb with pulse-width modulation (PWM). ….

Controlled Power Dimmer Kit This is based communications protocol that is commonly used for stage lighting and stage effects. If you ever wondered how do they control all those stage lights, lasers, and other effects remotely from a single control point, ….

LINEAR CONSTANT CURRENT White LED Dimmer This simple Linear circuit provides continuously variable regulated current (~25-400mA) from a 4-6 Volt source. I chose a linear design for simplicity, reliability, ease of repair, and to avoid switching EMI in my Cave Radios. ….

PIC16F84 Alarm Clock This is an alarm clock I built. It was very effective during the sort time I used it, because I programmed it to play a very annoying tune through a speaker. I actualy started to wake up before the alarm went of, so other people int he house didn’t wake up from the anoying pitches it played. …..

PIC16F628 Digital Clock Timer This clock timer uses a PIC16F628 microcontroller to display 3 and 1/2 digit time and control an external load. It can be programmed to time from 1 to 59 minutes. The clock includes a calendar with leap year and optional daylight savings adjustments. …

24 Second Shot Clock by IC digital o start in 24 seconds; 24s LOAD SW and Reset SW should be push simultaneously. If not, the count will start in 99. Pulse input can be connected to 555 astable multivibrator but must be calibrated for real time clock. The PAUSE SW must have a Switch Debouncer so that the counter will count normal when counting is paused and then turn-on….