JPS5813973Y2 - Ultrasonic transducer excitation device - Google Patents

Description

[Detailed description of the invention] This invention relates to an ultrasonic transducer excitation device that excites ultrasonic transducers used in acoustic sounders and vertical and horizontal fish finders that convert electrical signals into acoustic signals, and in particular, The present invention relates to an excitation device that does not shorten the life of the vibrator or destroy the vibrator driving transistor.

This invention will be explained below with reference to the drawings.

FIG. 1 shows a conventionally used ultrasonic transducer excitation device.

1 is a signal a k obtained by amplitude modulating an ultrasonic signal continuously generated by a signal generator with pulses, and is supplied to the primary side of the lance 2 .

Both ends of the secondary winding of the transformer 2 are connected to transistors Tr.
1 and Tr2 (connected to the D base, and their midpoint terminals are grounded.

The emitters of both transistors are commonly grounded through a resistor 3.

The collectors of both transistors are connected to both ends of the primary winding of the transformer 4, respectively.

A power source 5 is connected to the midpoint of the primary winding of the transformer 4 and supplies a DC voltage.

The secondary winding of the transformer 4 is connected to the vibrator 6.

In the above configuration, when the signal generator 1 generates the signal a at a constant period, the transistors Tr1 and Tr2 generate a voltage signal S having spikes at the rising and falling edges of the signal a on the collector.

Signal C indicates the current flowing between the collectors and emitters of transistors Tr1 and Tr2 at this time.

The reason why a spike appears at the rise of a pulse is because a pulse signal with a steep rise is applied when the resonator is not excited and the impedance is very high, resulting in overdrive, and the reason why a spike appears at the fall of a pulse is because This is because the transistors Trl and 'l'r2 become non-conductive and the circuit for discharging the energy stored in the inductance of the transformer 4 is lost, generating a back electromotive voltage.

The conventional button has a problem in that the voltage and current spikes described above destroy the transistors Tr1 and Tr2 and place a burden on the vibrator, shortening the usable period of the vibrator.

This invention solves the above-mentioned problem by supplying a signal obtained by amplitude-modulating all rising and falling edges of continuously generated ultrasonic signals with gentle curved pulses to the bases of transistors Tr1 and 'l'r2. Solve the points.

FIG. 2 shows an embodiment of this invention.

Transistor Tr3. The base of is connected to the input terminal and the input side of the inverter 10.

The output side of the inverter 10 is a transistor 'l'r4
connected to the base of

The emitter of the transistor Tr3 is the transistor Tr5.
, one end of the capacitor 11 and one end of the resistor 12 .

The collector of the transistor Tr4 is connected to the other end of the resistor 12, and its emitter is grounded.

The collector of the transistor Tr3 is connected to the power supply 5 via the resistor 13.
and connected to the collectors of transistors T r 5 e T r 6.

The emitter of transistor Tr5 is connected to the base of transistor Tr6.

The signal generator 14 generates a continuous ultrasonic signal, and its output terminal is connected to the transistor Tr7 and the inverter 15.

The output terminal of the inverter 15 is connected to the base of the transistor Tr8.

The collectors of transistors Tr7 and 'l'rB are connected to one ends of resistors 16.17 and 18.19, respectively,
The emitters are commonly grounded.

The other ends of the resistors 17 and 19 are connected to transistors Tr.
9 and the base of T rto.

The collectors of the transistors Trg and Trlo are respectively connected to both ends of the primary winding of the transformer 20, and their emitters are commonly grounded via a resistor 21.

The emitter of the transistor Tr6 is connected to the other ends of the resistors 16 and 18 and to the midpoint terminal of the primary winding of the transformer 20.

A transistor T is connected to each end of the secondary winding of the transformer 20.
It is connected to the bases of r11 and Tr12, and its midpoint terminal is grounded.

The emitters of the transistors Tru and Tr12 are commonly grounded through a resistor 22, and their collectors are connected to both ends of the primary winding of a transformer 23, respectively.

A midpoint terminal of the primary winding of the transformer 23 is connected to a power source 24 .

A secondary winding of the transformer 23 is connected to the vibrator 6.

In the above configuration, when the pulse signal d is supplied from the input terminal at time t1, the transistor Tr3 becomes conductive, but since the signal e inverted by the inverter 10 is applied to the base of the transistor Tr4, the transistor Tr4 does not become conductive. .

Therefore, the emitter voltage of the transistor 'l'r6 increases with a time constant determined by the resistor 13 and the capacitor 11, as shown by f.

Further, at time t2, the signal at the input terminal disappears, so the transformer Tr3 becomes non-conductive and the transistor 'l'r4 begins to conduct.

Therefore, the voltage at the emitter of the transistor Tr6 falls with a time constant determined by the resistor 12 and the capacitor 11, as shown by f.

The signal generator 14 supplies a continuous signal as shown in g to the base of the transistor Trg via the transistor T r 7 k and on the other hand to the base of the transistor Tr 10 via the inverter 15 and the transistor T r B.

On the other hand, a curved pulse signal with a gentle rise and fall as shown in f is supplied to the collectors of transistors Tr7 and Tr8 through resistors 16 and 18, respectively, and is also supplied to the midpoint terminal of the primary winding of the transformer 20. As a result, the transformer 20 generates a signal obtained by amplitude modulating the continuous ultrasonic signal with pulses as shown in h, and this signal is amplified by the transistors Tr11 and Tr12 and then sent to the transducer. 6 and is fired into the water.

As mentioned above, this invention uses a simple circuit configuration to generate vibrations by a signal obtained by amplitude modulating all the rising and falling waves of the continuously generated ultrasonic signal with gentle curved pulses. This allows a drive signal without spikes to be obtained, resulting in stable ultrasonic vibration that will not damage the output transistor or damage the transducer or cause damage to the oscillator during its use. Child exciter device can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows a conventional device, and FIG. 2 shows an embodiment of this invention. 1 is a signal generator, 5 is a power supply, 6 is a vibrator, 10 and 15
indicates an inverter, and 14 indicates a signal generator.

Claims (1)

[Claims for Utility Model Registration] The primary winding of a first transformer is connected between its collectors, the secondary winding of a second transformer is connected between its bases, and the midpoint of this secondary winding is First and second transistors with their terminals grounded and push-pull connected; an ultrasonic vibrator connected to the secondary winding of the first transformer; and a curved pulse with gentle rising and falling edges. a pulse generator that generates a signal, a continuous signal generator that continuously generates a predetermined frequency signal, an output signal of the continuous signal generator is supplied to its base, and a pulse output signal of the pulse generator is supplied to its collector. an ultrasonic transducer excitation device, comprising: a third transistor supplied with the third transistor, the collector of which is connected to the primary winding of the second transformer;