Saturday, August 15, 2009
This is a circuit diagram of an ultrasonic mosquito repeller (pengusi yamuk). The circuit is based on the theory that insects like mosquito can be repelled by using sound frequencies in the ultrasonic (above 20KHz) range. The circuit is nothing but a PLL IC CMOS 4047 wired as an oscillator working at 22KHz. A complementary symmetry amplifier consisting of four transistor is used to amplify the sound. Speaker Piezo buzzer converts the output of amplifier to ultrasonic sound that can be heard by the insects.
Skema Rangkaian Pengusir Nyamuk
The circuit can be powered from 12V DC. The buzzer can be any general purpose piezo buzzer.
Description IC CD4047B
IC CD4047B is capable of operating in either the monostable or astable mode. It requires an external capacitor (between pins 1 and 3) and an external resistor (between pins 2 and 3) to determine the output pulse width in the monostable mode, and the output frequency in the astable mode. Astable operation is enabled by a high level on the astable input or low level on the astable input. The output frequency (at 50% duty cycle) at Q and Q outputs is determined by the timing components. A frequency twice that of Q is available at the Oscillator Output; a 50% duty cycle is not guaranteed. Monostable operation is obtained when the device is triggered by low-to-high transition at a trigger input or high-tolow transition at b trigger input. The device can be retriggered by applying a simultaneous low-to-high transition to
both the a trigger and retrigger inputs. A high level on Reset input resets the outputs Q to low, Q to high.
Lay out IC CD4047B
IC CD4047B Applications