Infra-Red Sensor/Monitor
The sensor/monitor shown in the diagram wakes up` the host system on detection of infra-red (IR) signals. It draws so little supply current that it can remain o...
Heart Rate Monitor
Strictly speaking, this simple circuit shouldn`t work! How could anyone expect an ordinary light dependent resistor photo cell to `see` through a fingertip in n...
Energy Leak Detector
This sensitive circuit is basically a comparator, detecting very slight temperature changes in respect to the ambient temperature. It was primarily intended to ...
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 tou...
Body Charge Detector
It is well known that through such simple everyday activities as walking on a carpet or moving in a chair, the body accumulates a static charge - sometimes many...
Beam-break Detector For Camera Shutter or Flash Control
This circuit is presented as an alternative to the IR beam break detector featured in the June 2009 issue (Silicon Chip). In order to make it relatively insensi...
AFX Slot Car Lap Counter
AFX slot car sets are very enjoyable but you can increase the fun with a lap counter. This circuit will count from 00 to 99, with independent counters for each ...
Acoustic Sensor
This acoustic sensor was originally developed for an industrial application (monitoring a siren), but will also find many domestic applications. Note that the s...
Vibration Detector Circuit
The sensors are a thin strip of piezoelectric material with a rivet in the end acting as a weight. When there is a vibration, the weight moves, stressing the pi...
Temperature Sensor Circuit
The IC we will use to measure the temperature is the TMP36 IC. We will integrate this with the arduino to measure the temperature. The arduino will then read th...
Proximity Detector Circuit
There are 2 ways to build a protximity detector. One is mount the IR LED and the phototransistor so that they face each other. Then the infrared light is detect...
Touch Sensor Circuit
In this project we`re going to use use two wires, in this project, we use one red and the other blue, which serve as the touch sensor wires. When a person touch...
Simple Photoresistor Circuit
Now we will build a very simple photoresistor circuit to make a photoresistor do what it does: make the circuit work when there is light and stop working when t...
Hall Effect Sensor Circuit
The hall effect sensor we will use in this circuit is an A1302 hall effect sensor manufactured by Allegro. This IC can detect magnetic fields. We will then conn...
Accelerometer Circuit
As you are probably familiar, an accelerometer is a device that can measure dynamic acceleration (vibrations) and static acceleration (gravity). Being that it m...
Water Activated Relay
In his circuit Marin has used two transistors wired as a high gain compound pair. Transistor T1 may be a 2N2222A and T2 a BC108. The current gain will be the ...
1980 RCA TC-2811 First Generation CCD Surveillance Camera
RCA made some of the first commercially available CCD chips. A CCD (Charge Couple Device) is a silicon solid state imaging device that replaces the vidicon tube...
Multi-Purpose Digital Laser Sensor
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Building a Wireless Temperature Sensor
A wireless temperature sensor so that temperature measurements can be made anywhere within the range of the transmitter and the receiver. There are many ways to...
A Sensitive DIY Ultrasonic Range Sensor
Some ultrasonic range finders for my project. But most of the commercial sensors like Parallax`s PING sensor and other similar products are quite expensive, esp...