Detector Electronics | Electronic Project Circuits

Posts Tagged ‘detector electronics’

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 thousands of volts. Due to its extreme sensitivity, this circuit will detect not only such charges but also EMF-induced voltages in the body, which are generally far smaller. This means that, whether you happen to be “charged up” on any particular day or not, your body will almost certainly trigger this circuit.

An interesting twist is that the sensor does not need to be made of metal. Provided it is isolated from ground, the sensor can be any conductor, including a plant in a pot. The circuit is a comparator based on an LF351 FET-input op amp (IC1). The has the benefit of a high impedance input which is crucial for detecting a static charge. The other aspect which is crucial is that the 0V side of the circuit must be connected to earth (eg, a metal stake driven into the ground). Without the grounded connection, the circuit will yield poor results.
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Author: Thomas Scarborough – Copyright: Silicon Chip Electronics
Source: http://www.extremecircuits.net/2010/06/body-charge-detector_09.html

Be the first to comment - What do you think? Posted by admin - March 24, 2011 at 6:45 am

Categories: Detector Tags: detector electronics, emf strength meters

Pipe Descaler

For many years now, magnetic (or electromagnetic) water descaler devices have been showing up on the shelves of Home Improvement and other DIY stores all over Europe. Despite the numerous studies completed on that subject, by manufacturers as well as by various consumer associations, none have been able to conclude on the efficiency of commercial pipe descalers in a decisive manner. Since electronic devices of this type are relatively expensive (especially when we discover what they are made of!), we decided to offer this project to our readers.

For the price of a few tens of pounds, you will be able to evaluate the state of your own faucets, pots, and other pipes. The device we’re offering as a project is identical to top-of-the-line items found on sale; in other words, it includes the bi-frequency option because it seemed that would be the best way to fight lime scale deposits. An initial astable oscillator, based on a traditional 555, labeled IC3, functions at around 10 kHz when the only capacitor C6 is operating; in other words, when T1 is blocked. The latter is controlled by another astable oscillator, based on IC1 this time, but which functions at about 1 Hz.
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Author: Christian Tavernier – Copyright: Elektor Electronics
Read more : http://www.extremecircuits.net/2010/06/pipe-descaler_8700.html

Be the first to comment - What do you think? Posted by admin - March 9, 2011 at 12:08 am

Categories: Detector Tags: detector electronics, metal detector

Proximity Detector Using CS209

This is a simple proximity detector using IC CS209. The CS209A is a bipolar monolithic integrated circuit for use in metal detection/proximity sensing applications.The CS209A contains an oscillator set up by an external parallel resonant tank and a feedback resistor connected between pin 2 & 3.
The internal oscillator operates close to the resonant frequency of the tank circuit.As a metal object is brought close to the inductor, the amplitude of the voltage across the tank gradually begins to drop. When the envelope of the oscillation reaches a certain level, the IC causes the outputs to toggle states.potentiometer connected between pin 1 & 8 is adjusted to achieve a certain detection distance range. The larger the resistance the greater the trip-point distance.

Source: http://applicationcircuit.blogspot.com/2008/07/
proximity-detector-using-cs209.html