40kHZ ultrasonic transmitter circuit (1)
40kHZ one ultrasonic transmitter circuit, the F1 ~ F3 three oscillators in the F3 is 40kHZ square wave output, frequency mainly by C1, R1 and RP decided to adjust the adjustable resistance with a frequency of RP. F3 transducer excitation output T40-16 at one end and the inverter F4, F4 transducer excitation output T40-16 the other end, therefore, join F4 doubling the excitation voltage. Capacitors C3, C2 and F4 F3 balance the output of the waveform is stable. Inverter circuit, F1 ~ F4 with the CC4069 in four of six inverter inverter, and the remaining two do not (input should be grounded.) Power Supply 9V laminated battery. F3 output frequency measurement should be 40kHZ ± 2kHZ, or should be adjusted RP. Transmitting ultrasonic signals greater than 8m.
40kHZ ultrasonic transmitter circuit (2)
40kHZ second ultrasonic transmitting circuit, the circuit transistors VT1, VT2 form strong feedback resonator oscillator, the oscillation frequency equal to the ultrasonic transducer T40-16 resonant frequency. T40-16 is the feedback coupling element, the circuit is the output for the transducer. T40-16 is similar at both ends of the square wave oscillation waveform, voltage amplitude close to the power supply voltage. S is the power switch, click S, T40-16 can drive a string of 40kHZ emitted ultrasonic signals. Circuit voltage of 9V, the operating current of about 25mA. Transmitting ultrasonic signals greater than 8m. Circuit can work without debugging.
40kHZ ultrasonic transmitter circuit (3)
40kHZ ultrasonic transmitter circuit, produced by the VT1, VT2 positive feedback form feedback oscillator. Circuit oscillation frequency depends on the feedback element of the T40-16, the resonant frequency of 40kHZ ± 2kHZ. Frequency stability, no need to make any adjustment by the T40-16 as a transducer of the ultrasonic signals emitted 40kHZ. Inductor L1 and capacitor C2 for resonance tuning role played in the 40kHZ. Voltage of the circuit to adapt to a wide (3 ~ 12V), and the frequency change. Using fixed inductors, inductance 5.1mH. Machine operating current of about 25mA. Transmitting ultrasonic signals greater than 8m.
40kHZ ultrasonic transmitter circuit (4)
40kHZ four ultrasonic transmitter circuit, which consists of four complete and non-oscillation, and gate drive functions CC4011 by ultrasonic transducer T40-16 to control the receiver, the ultrasound radiation. Which formed the door YF1 controlled oscillator with the door YF2, when S is pressed, the oscillator start-up, adjust the RP change the oscillation frequency, should be 40kHZ.Oscillations are controlled by YF4, YF3 drive differential phase composition of the work, when YF3 output goes high, YF4 certain output low; YF3 output low, YF4 output high. The T40-16 level control issue 40kHZ ultrasonic transducer. Circuit YF1 ~ YF4 four high-speed CMOS circuit 74HC00 NAND gate circuit, the output drive current is characterized by large (greater than 15mA), high efficiency. Circuit voltage of 9V, operating current greater than 35mA, transmitting ultrasonic signal is greater than 10m.
40kHZ ultrasonic transmitting circuit (5)
40kHZ five ultrasonic transmitting circuit, time base circuit by the LM555 and the external components, the 40kHZ multivibrator circuit, adjust the resistance of resistor RP can change the oscillation frequency. 3 feet from the LM555 output drives ultrasonic transducer T40 -16, so that emit ultrasonic signals. Circuit is simple and easy system. Circuit voltage of 9V, working current 40 ~ 50mA. Transmitting ultrasonic signals greater than 8m. LM555 NE555 direct replacement is available, the effect is the same.
Bistable ultrasonic receiver circuit
Since no single-state receiver and memory function, it can not be used in home appliances on and off, the application surface is not wide. Ultrasonic receiver circuit is a bistable, and its front-end circuit with the same circuit diagram 2-186, but the implementation of the circuit are different.
Circuit, the VT5, VT6 and auxiliary components, the bistable circuit, when the conduction time of each VT4 (transmitter work once), the trigger signal by the C7, C8 bistable circuit is sent to a trigger pulse, VT5, VT6 state Flip once, when the VT6 from closing state into a conduction state, VD5 end, VT7 closing, relay K release; when again a trigger signal, VT6 turn into a cut-off by the state, VD5 conduction, VT7 conduction , relay K pull …… due to the increase bistable circuit, so for lights, fans, TV and other electrical remote control become a reality. Debugging, in a point and +6 V (power supply) rapidly with a wire between the short bit after the release, the relay should pull (or release), and then release the short-circuit what the relay should be released (or pull), if Relay no response, check the weld quality bistable circuit components and component parameters.Under normal circumstances one can succeed.
Monostable ultrasonic receiver circuit
Monostable ultrasonic receiver circuit schematics, ultrasonic transducer R40-16 resonant frequency 40kHZ, selected frequency by R40-16, will be outside the interference signal attenuation 40kHZ only resonant in the 40kHZ useful signal (transmitter signal) VT1 ~ VT3 formed into high-pass amplifier, the C5, VD1 DC component detection, control, VT4, VT5 driven electronic switch consisting of K relays work. Since the circuit only for one-way signal amplifier, when an ultrasonic signal transmitters each transmitter, the receiver relay time (time to pull the same time with the transmitter transmitting the signal), with no memory retention function. Used as a wireless remote camera shutter control, control of children’s toys, curtains and control. Circuit VT1β ≥ 200, VT2β ≥ 150, other components custom. Circuit can work without debugging. Such as sensitivity and interference is not enough, you can check the transistor and capacitor C4 of β value of the capacity is too much deviation. Experimental results, with the corresponding transmitter, remote control distance of up to 8m or more. Reflected by the wall in the room, there is no direction. Circuit voltage of 3V, the static current of less than 10mA.