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Return to Blog500Hz Modulated Ultrasonic Transmitter
Posted Jan 25, 2012 at 1:32 pm
Figure 1
Ultrasonic oscillations which are generated by unmodulated ultrasonic transmitters commonly for remote control are usually affected from other ultrasonic sources in the media and that’s why we are giving a 500Hz modulated ultrasonic transmitter circuit here.
Voltage supply of the circuit is 9 Volts and any change of the value will change the frequency also. You can omit this difference by connecting a resistor between A and B nodes. You can find the value of the resistor by using this formula:
Figure 2
The multivibrator generates 500Hz modulation frequency. To avoid the frequency differences , tolerance of the circuit should not exceed %5.
If the circuit components changed, then the frequency can be determined by using the formula below,
Figure 3
If C1 and C3 are nanofarads then R2 and R3 will be magaohms.
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3 years ago: in which equipments can the remote control using this circuit may be applied?
2 years ago: can the circuit handle it if the frequency is increased? will it be harmful to health?
2 years ago: when u say ultrasonic, what is the frequency range where it operates?