In many cases, a doorbell that sounds off a musical tone is preferable over the common buzz sound. This featured circuit is a musical doorbell. After t...
Opening cars door is very simple activity, and off course its just a daily activity which require no special skill. Almost nothing can go wrong, but fo...
A data output buffer for use in a semiconductor memory with a junction-field-effect-transistor. The data output buffer has a N-channelMOSFET TN1 with i...
This circuit automatically turns on a night lamp when bedroom light is switched off. The lamp remains ON until the light sensor senses daylight in the ...
Hack Your Doorbell Ripped from the pages of Popular Science (December 2007) Customize your dingdong with a Dingtone It seems like everywhere you go, so...
This is the 1Hz clock generator circuit with Chip On Board (COB). Commonly, the circuits to produce 1Hz clock for digital clock and counter circuits ap...
This article describes the Fridge door Alarm (CD4060). The principle is very simple, very practical. The circuit components can help you understand bet...
Wireless portable unit Adaptable with most internal combustion engine vehicles Circuit diagram Parts: R1,R2,R19 1K 1/4W ResistorsR3-R6,R13,R17 100K 1/4...
This infrared alarm barrier can be used to detect persons passing through doorways, corridors and small gates. The transmitter emits a beam of infrared...
This article describes the Door Bell Circuit Schematic Diagram (SI4425BDY). The content is very simple, very helpful. Components in this article can he...
The Lamp flashing circuit is basic flasher 6V that low current and small size. which we use the transistors are 2 pcs ,is NPN 2N3904 and PNP-2N3906 typ...
The article describes a single CMOS alarm circuit. The circuit is very simple, very helpful. If you understand this principle is not very thorough, it ...
We understand the importance of home security and specialise in the installing and servicing of security systems. This alarm features open- and closed-...
Remote Alarm For Smoke Detector Description This alarm circuit was designed to monitor a mains-poweredsmoke detectorlocated in a shed (which is used to...
This article briefly describes the Infrared Proximity Detector Alarm (LD274). Although this circuit is very easy to understand, but also very practical...
A burglar alarm circuit is designed to sound an alarm when the circuit is broken. Find out how a burglar alarm circuit works and see inside a magnetic ...
Software: The software is written in a state machine manner. Here are the states: (the state numbers were chosen randomly) State 1: Show the power up g...
This article is Everything - that - moves the ALARM circuit diagram. The circuit is not new, but it proved so useful, simple and cheap, worth building....
A wire loop is used to protect valuable objects in this alarm circuit. The circuit is powered by a 9v battery. Reprinted Url Of This Article: http://ww...
It is often desirable for a single doorbell to be operated by two buttons, for instance, one at the front door and the other at the back door. The addi...
This simple and cost-effective ding dong electronic doorbell circuit is based on IC 8021-2. The IC has an in-built circuitry to produce ding dong sound...
Figure 1 4511 – a BCD to 7-segment decoder driver used to convert the logic states at the outputs of a binary coded decimal ( BCD ) into signals that...
This article describes the RC Receiver Battery Low Voltage Alarm (2N3906). The content is very simple, very helpful. Diagram showing the principle is a...
This simple fake car alarm or alarm decoy circuit device will simulate the presence of a burglar alarm in automobiles or homes. It has a few components...
Description. This circuit will produce a visual as well as audible alert whenever the connection between the charger circuit and the battery being char...
As long as the temperature of the air near the ground close to 0:00, the alarm circuit will be prompted to cars drivers may be icy pavement this inform...
Beeper or flashing LED alert, 1.5V battery powered portable unit This circuit will emit an intermittent beep (or will flash a LED) when the water conta...
This article is the display of the principle of the water level indicator and alarm. The circuit not only suggest that amount of water in the high slot...
Doorbell Circuit Description Here is a simple and easy to builddoorbell circuitusing IC UM 66.The? details of UM 66? is given in the older post Melody ...
Description This circuit, enclosed in a small plastic box, can be placed into a bag or handbag. A small magnet is placed close to the reed switch and c...
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