DE2441642A1 - CIRCUIT ARRANGEMENT FOR GENERATING A NON-SINE SIGNAL SIGNAL - Google Patents

Description

PATENT LAWYERS

DR.-ING. HANS LEYH ERNST RATHMANN

Munich 71, Melchiorstr. 42

Our reference: MO166P-1216

MOTOROLA, INC. 5725 East River Road Chicago, Illinois USA '

Circuit arrangement for generating a non-sinusoidal

Signals

The invention relates to a circuit arrangement for generating . a non-sinusoidal vibrator signal that has a periodic complex waveform.

The invention relates in particular to a circuit arrangement for generating vibrator signals for musical instruments.

There are numerous applications in which vibrator systems are desired for musical instruments, for example in an electronic organ. In this case the vibrator signal is applied to a main oscillator of the organ in order to modulate the frequency of the oscillator in order to produce the vibrator effect produce.

Methods for generating a vibrator signal are known. They use oscillator systems that provide a substantially sinusoidal vibrator signal, as well as more complex systems that deliver

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generate a vibrator signal with a particular desired waveform.

The latter are extremely complex and very expensive to manufacture, while the former system, the one sinusoidal wave, has poor sound quality.

The invention is therefore based on the object of creating a circuit for generating a vibrator system that enables the generation a non-sinusoidal vibrator signal that allows fuller sounds with higher sound quality.

According to the invention, this is achieved by a first low frequency Oscillator with a frequency-determining circuit which is tuned to a first frequency to generate first oscillations to generate with the first predetermined frequency, a second low-frequency oscillator with a frequency-determining Circuit tuned to a second frequency higher than the first frequency and a predetermined even number A multiple of this is, in order to generate second oscillations with the second predetermined frequency, a coupling circuit, the the first and the second oscillator connects to phase-locked the second oscillations to the predetermined frequency multiple synchronize the first oscillations and through a circuit connected to the first and the second oscillator is to receive and combine the first and second oscillations, the circuit at its output the combined provides first and second oscillations to produce the periodic complex waveform.

Preferably the first oscillator operates at a frequency of e.g. 6 Hz, while the second oscillator operates at a frequency of e.g. 12 Ez works.

An example embodiment of the invention is based on the

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Drawing explained in the

Fig. 1 schematically shows a circuit according to the invention for use at an organ shows.

Fig. 2 shows a waveform of the complex vibrator signal o according to the invention

Fig. 1 shows a master oscillator 10 for an organ having transistors 12, 14, 16 and 18 and the associated components. In the case of the transistors 12 and 14, the collectors and the emitters are correspondingly connected, while their bases are connected via resistors 20 and 22. In the same way, the collectors and the emitters of the transistors 16 and 18 are correspondingly coupled, while the bases are connected via resistors 24 and 26. The emitters of transistors 12, 14, 16 and 18 are grounded and the collectors of transistors 12 and 14 are connected to an energy source A + via a resistor 28 and the collectors of transistors 16 and 18 are connected to the energy source A + via a resistor 30. The collectors of transistors 16 and 18 are connected to the bases of transistors 12 and 14 via resistors 20 and 22. Similarly, the collectors of transistors 12 and 14 are connected to the bases of transistors 16, 18 via resistors 24, 26 and a frequency-determining circuit made up of capacitors 32, 34, a resistor 36, a crystal 38 and a switch 40. The collectors of transistors 12 and 14 are connected to a group of frequency dividers 42 which produce musical sound frequencies. The output of the frequency dividers 42 is connected to a keyboard 44 which selectively applies a tone from the frequency dividers 42 to an amplifier 46 for reproduction by a speaker system 48.

The generator system includes a first oscillator 50 having transistors

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52 and 54 and a second oscillator 70 with transistors 72 and 74. In the oscillator 50, the transistors 52 and 54 are Connected in parallel via resistors 56 and 58 in a manner similar to that of transistors 12, 14 and 16, 18. The emitters of the Transistors 52, 54 are grounded while the collectors are connected to the energy source A + via a resistor 59. the Collectors of transistors 52, 54 are also connected through a twin T feedback circuit, resistors 60-62 and capacitors 64 to 66 connected to their bases.

The structure of the oscillator 70 is similar to that of the oscillator 50, with the feedback between the collectors and bases of transistors 72, 74 through resistors 76, 80 and a frequency-determining network is formed, the resistors 80 to 32 and capacitors 84 to 86. The frequency-determining ones Circuits of the two oscillators are coupled via a resistor 90, one end of which is at the junction of the resistor 62 and the capacitors 64, 65 and the other end at the junction of the resistor 82 and the Capacitors 84 and 85 is located.

A circuit 100 includes a variable resistor 96 which is grounded, a resistor 92 which is connected to the collectors of the Transistors 52 ', 54 is connected and a resistor 94, which is connected to the junction of the collectors of the transistors 72, 74 is laid. The junction of resistors 24, 26 is connected to the junction of resistors 92, 94 and 96.

During operation, the oscillator sends 10 oscillations to the frequency divider 42; the musically coherent tones on the keyboard 44 there. The keyboard 44 selects one or more of the notes to be played and outputs the selected notes to an amplifier 46 for reproduction through the loudspeaker 48. The oscillator 10 has eisien switch 40 through which when in the position shown is, the frequency of the oscillator 10 is determined by the crystal 38

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is controlled. If the switch 40 is in its other switch position brought, the crystal is switched off and the oscillation frequency is determined by the capacitor 32.

The oscillator 10 can be frequency modulated by applying it a signal to the junction of resistors 24 and 26 to increase the junction capacitance between the base and emitter of the To change transistors 16 and 18, whereby the oscillation frequency of the oscillator 10 is changed.

The oscillator 50 operates at a low frequency, e.g. 6 Hz, with the oscillation frequency being provided by the twin T-network is determined, which includes the resistors 60 to 62 and the capacitors 64 to 66. The oscillation frequency of the Oscillator 70 is selected as a multiple of the oscillation frequency of oscillator 50, for example 12 Hz. As in Oscillator 50, the frequency of the oscillator 70 is determined by the network, the resistors 80 to 82 and the capacitors 84 to 86 contains.

The twin T-networks of oscillators 50 and 70 are over The resistor is connected together to synchronize the two oscillators. The connection between the two networks causes the two oscillators to operate in a predetermined rigid phase relationship to create a periodic complex Deliver waveform. The complex waveform is obtained by combining the 6 Hz signal from the oscillator 50 and of the 12 Hz signal from oscillator 70 via resistors 92, 94 and 96. A typical waveform resulting at the junction of resistors 92, 94 and 96 is shown in FIG. The complex waveform that occurs at the junction of resistors 92, 94 and 96 is applied to the bases of the transistors 16 and 18 placed to match the frequency of the oscillator 10 to change with the complex function of FIG.

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The strength of the vibrato effect is via the variable resistance 96 adjustable.

By using the complex wave created by the combination of the two harmonically matching phase-locked signals of the oscillators 50 and 70 is produced, a more pleasant result results Vibrator effect with a fuller sound and better sound quality than was previously possible. The circuit according to the invention is easy to manufacture using integrated circuits, which use four double-entry gates connected as shown in FIG. Alternatively, the circuit also using individual transistors instead of the transistor pairs 12, 14; 16.18; 52, 54 and 72, 74 executed will.

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Claims (1)

Claims 'l.) Circuit arrangement for generating a non-sinusoidal Vibrator signal with a periodic complex waveform, characterized by a first low-frequency oscillator (50) with a frequency-determining Circuit (60, 61, 62, 64, 65, 66), which is tuned to a first frequency, with the first oscillations generate the first predetermined frequency; a second low-frequency oscillator (70) with a frequency-determining Circuit (SO, 81, 82, 84, 85, 86) tuned to a second frequency that is higher than the first Frequency and a predetermined even multiple of this is to give second oscillations with the second predetermined Generate frequency; a coupling circuit (90) connecting the two oscillators to the second Synchronize phase-locked vibrations with the specified frequency multiple of the first vibrations and by a circuit (100) connected to the two oscillators to combine the two oscillations and to output a signal combined from the first and the second oscillation at its output in order to produce the periodic create complex waveform. ο Circuit arrangement according to claim 1, characterized that each of the frequency-determining circuits has a twin T-network and that the Coupling circuit (90) contains a resistor. 3ο circuit arrangement according to claim 1 or 2, characterized in that the circuit (100) resistors (92, 94, 96) contains. 509813/0320 4. Circuit arrangement according to one of the preceding claims, characterized in that the frequency-determining network of the oscillator (70) doubles the frequency of the frequency-determining circuit of the oscillator (50) is coordinated. 5. Circuit arrangement according to one of the preceding claims, characterized by an oscillator (10) for generating a musical tone associated with the circuit (100) is connected and responsive to the non-sinusoidal signal to periodically increase the frequency of the musical To change tones accordingly. 6. Circuit arrangement according to claim 5, characterized by a frequency divider (42) for generating musical tones, which is connected to the oscillator (10) is. 509813/0320