As you know, piezoelectric transducers tricycles have a capacitive character of the load. Therefore, appropriate is required control. On the one hand, the transmitter is fed directly from the US2 generator output to construction that I used the 555...Electronics Projects, Portable Mosquito Repellent Circuit "analog circuits projects, " Date 2019/08/04
As you know, piezoelectric transducers tricycles have a capacitive character of the load. Therefore, appropriate is required control. On the one hand, the transmitter is fed directly from the US2 generator output to construction that I used the 555 tajmer in the CMOS version. The other side of the transducer, on the other hand it is connected to the output of the reverse transistor-like phase inverter signal. In this way I baked two birds with one stone. I ensured proper control the piezo element and built a bridge circuit that ensures maximum utilization of the supply voltage the resulting system and thus the maximum power delivered to the transducer. I was not tempted to fun with the coil increasing the tension because the problem of mosquitoes I decided to solve locally around oneself. Let others also get a little revenge and build Mosquito Repellent Circuit themselves. If they will not they could come to me and then a little
The anti-parallel stage works in an inverted system in relation to what is found in the power terminals. Simply put emitters transistors T1 and T2 are connected to the power supply and to the ground. When there is a state at the US1 output the high transistor T1 is clogged and the transistor T2 is open. So the transmitter has a full voltage supply.
Resting frequency Generator operation is set to 38 kHz and can be changed by inserting the R5 o resistor in the system another value. In the modulation system, I used the US1B operating amplifier operating as are-generator I was taking on 2 kHz according to the instructions of a mosquito literalist. Frequency of work the relaxation generator depends on several factors, in fact all the elements from which it folds except for the operational amplifier. Of course, the steady influence has the greatest impact time R1, C1. The R2 ÷ R4 resistors have a smaller impact.
Mosquito Repellent Circuit Schematic
The latter, however, affect the amplitude of the triangular waveform occurring on the capacitor C1. At the output of the amplifier operational US1B receives an unnecessary rectangular course here. I have chosen the elements’ values in such a way that the triangular triangle (value interpass) has a value of approx. 2V with a constant component of approx. 8 V. This voltage is I worked for the second US1A amplifier working as a voltage repeater. In this way I have separated the US1B generator from the load, which is the modulating input of the 555 system. the tajmer frequency changes cyclically around the selected 38 kHz central frequency. The system is powered by a miniature 12V battery type MN 21. Battery