Measurement
Diode electronic thermometer
This thermometer circuit uses a common 1N4148 diode as the temperature sensor. The temperature coefficient of the diode, -2 mV / 0C is exploited for this application to create an accurate electronic thermometer. To display the measured temperature, a digital multimeter is used and so we can measure temperature values from -9.990C up to +99.90C.
Field strength meter
A sensitive and reliable field strength meter is an invaluable instrument in amateur radio and in radio controlled model area. A field strength meter is used to align an antenna to get the best possible gain, to determine the transmitting range of radio controllers …
Designing the field strength meter to be sensitive it is [...]
Mobile phone sniffer - gsm telephone detector
With this mobile phone sniffer will track down mobile phones. Use this handy directional finder in situations and locations where the use of a mobile phone is forbidden. This neat unit will not only detect the presence of mobile phone activity (voice or text), it can home in on the culprit!
Apart from mobile phones this [...]
