Saturday, July 2, 2011

Electronic Mosquito Repellent Using IC 555

This circuit can help you by keeping the mosquito and similar Insects and other creatures away from you using a high frequency sound produced by this circuit.

The main principle in the which this electronic mosquito repellent works Is that mosquito and Insects are highly sensitive to some frequency of sound and They Do not like the sound. And Insects and mosquito Will leave or get away from you due to the annoying sound. But the sound it produces is of a high frequency of the which can not be Heard by Humans so you will not be affected by the sound.
Electronic Mosquito Repellent Circuit Using IC 555
In the circuit timer IC 555 is used as it generates an oscillator frequency of about 62 KHz, the working frequency of the circuit can be set by rotating the preset resistor R2, and the speaker converts the electronic frequency to sound frequency. Try to keep the frequency of the sound as high as possible. And Make sure you do not Hear the sound of this circuit by keeping it above 20 KHZ, the annoying sound Will be Heard by Insects but not by you Because Humans do not normally Hear the sound of higher frequency than 20 KHz.

for better results use a speaker of good quality in the circuit, using good quality speaker Will Ensure That Will the project work.
Detail download here

Friday, July 1, 2011

BC548C Transistor Water Level Buzzer

This is the circuit of a simple buzzer corrosion free water level indicator for home and industries. This circuit is very simple because it uses only two transistors and some passip Components are easily found circulating in the electronics stores.
BC548C  transistor water level buzzer Circuit
When the water reaches the sensor, BC548C Transistor base is connected to the positive terminal. In consequence the transistor is opening and the buzzer it makes a buzz. Function: In the water level indicator, buzzer will be activated in order to make a noise when a certain level of water is being reached.
BC548C  Pins
Detail download here