Guys from Youritronics.com made a new project 74HC4051 Analog Multiplexer. They have a job to measure the temperature of 32 thermistors (NTC) with microcontroller and later process the data. With just four 74HC4051 they made multiplex 32 input channels to 4 outputs.

Overcome the fear of losing flying model or a model that forced landed. The touch down aircraft model is easier to findin dense shrubs and branches where acoustic marked. Electronic device for acoustic localization produces penetrating acoustic signal with two tones that will sound when the aircraft will lose telecommand signal. Anxiety and fear of [...]

Dual color (4 line x 3 column) led, 12 white and 12 blue are intermittently switched controlled by two NPN transistors BC337. The speed and duty/cycle timing of lighting duration is determined by NE555 oscilator. The number of repetition of sequential lighting of each group of led is determined by 5-stage divide-by-10 Johnson counter with [...]

Nowadays is so easy to build precision digital LC meter with LCD display and microcontrollers.But, what about 1997? There is my first very precision ANALOG LC METER. Look at this, butdo not fall in love in retro princess from past!!The analog LC-meter project (AP-LC1) have more then 3% accuracy. Really!There is no balanced bridge, or [...]

If you hate paying big roaming bills while traveling but still want to use your current GSM phone number to receive/make calls (and SMS) then consider using Skype in combination with this piece of free software and a cheap USB GSM/GPRS modem. This device (software actually) is also useful if your country is not in [...]

The project is designed to control an heating system in order to keep the temperature in a room above a certain value, which can be set from Internet or a Personal Computer by LAN, because ours is not a simple thermostat but a complex unit managed by Arduino, which can connect to a local network [...]

This is a very simple circuit to make using a 555 component and is recommended for the electronics beginner. The idea is to have a flashing red led indicate that your car is protected. This device can protect your vehicle from potential thieves – it makes it look like your car has an armed alarm [...]

The TV-B-Gone is a neat little device that can turn almost any TV on or off. It uses a microcontroller hooked up to IR LEDs to output a library of on/off codes. Adafruit sells a kit, and has the code as well as the schematic on their website. Here’s a micro clone of the TV-B-Gone [...]

This circuit allows switching on a LED when the battery voltage (12V) drops below a certain threshold. The operating system is based on a comparison of tension, which comes in a zener diode. If the supply voltage is 12V and the zener diode is a 10V model (this is the case in the diagram), we [...]

The following construction of low-frequency harmonic signal generator was necessary for debugging and measurement of audio amplifiers and other circuits, working in the audio band. The circuit is used in conjunction with low frequency (million) a voltmeter,oscilloscope or meter bias and provides an invaluable tool for checking and debugging all levels of the amplifier chain. [...]

This is a simple circuit to connect your VGA graphics card to your TV. The advantage of using RGB over S-Video is superior contrast and clarity. The schematic of this circuit is taken from Tomi Engdahl’s site. The circuit basically XORs together your horizontal and vertical synchronization signals to create a composite sync output, and [...]