Let’s see the top 10 electronic circuits for February 2011. As you probably already know, we will try to give you every month the most viewed articles on electroschematics.com. I don’t know if this helps you with something but the stats shows that the top 10 articles are viewed by a lot of people.
February 2011 Top 10 Electronic Projects and Circuits
- Cell phone jammer
A beautiful diy gsm jammer or mobile cell phone jammer schematic diagram for use only in GSM1900 with frequency from 1930 MHz to 1990 MHz. The GSM1900 mobile phone network is used by USA, Canada and most of the countries in South America.
- LED circuits
Some DIY LED circuits and projects…
- diy metal detector
The heart of this diy metal detector circuit is CS209A. The metal detector it is build with one coil of 100uH. CS209A has one oscillator wich forms an LC circuit, the inductance of the coil will change when it is near metal objects.
- Panic alarm
Imagine the Panic situation in the Midnight when an intruder tries to break into the house. This Alarm will help you with its loud Police siren to abort the attempt of intrusion. With a single clap, the circuit generates the alarm for three minutes and then goes off. This is sufficient to catch the attention of neighbours.
- Freezer alarm
Here is a simple freezer alarm circuit, but ultra sensitive with a buzzer. The circuit raises an audio alert when the temperature inside the freezer box goes up above a preset level. The circuit requires 9V dc supply and can power from a standard 9V alkaline battery.
- Hearing aid
This low-cost, general-purpose electronic hearing aids works off 3V DC (2×1.5V battery). Transistor T1 and associated components form the audio signal preamplifier for the acoustic signals picked up by the condenser microphone and converted into corresponding electrical signals.
- Infrared alarm
This infrared alarm barrier can be used to detect persons passing through doorways, corridors and small gates. The transmitter emits a beam of infrared light which is invisible to the human eye. The buzzer at the output of the receiver is activated when the light beam is interrupted by a person passing through it.
- Fire alarm
In this fire alarm circuit project, a thermistor works as the heat sensor. When temperature increases, its resistance decreases, and vice versa.
- Time delay circuit
This Time Delay circuit is useful to switch on an AC load such as lamps after the delay of three minutes. This protects the load from inrush current and transients at power on which may be detrimental to the device.
- Wireless light switch
You may use this wireless light switch instead of physical contact with switches which may be dangerous if there is any shorting. The wireless light switch circuit described here requires no physical contact for operating the appliance.
That’s all folks!