PL233810B1 - Gramophone turntable speed controller with wireless measuring of actual rotational speed - Google Patents

Description

The subject of the invention is a speed controller of an AC synchronous motor driving a turntable for playing analog vinyl records with a record clamp located centrally on the turntable spindle containing an electronic gyroscope, microprocessor, radio transmitter and battery measuring the actual rotational speed of the platter and transmitting the measurement results to the controller by radio. .

There are known methods of measuring the rotational speed of an object using a gyroscope, transmitting the measurement result by radio. The patent description CN203629581 describes a solution in which radio transmission was used to transmit information about the rotational speed of an object using an electronic gyroscope and an accelerometer mounted together with a control microprocessor and a battery on a rotating object. The patent description CN105954533 describes a solution which uses radio transmission to transmit information about the speed of a vehicle wheel using an electronic gyroscope mounted together with a control microprocessor and a battery on a rotating wheel.

In these solutions, it is not possible to set the set rotational speed by means of the speed selection buttons, and the speed detector itself is not mounted in the axis of the rotating object. In order to calculate the rotational speed, a three-axis gyroscope and a three-axis accelerometer (CN203629581) or at least a biaxial gyroscope (CN105954533) were used, which complicates these solutions.

The currently known rotary speed regulators of an analog turntable do not have the possibility of measuring the actual rotational speed of the platter. They operate on the assumption that the gear of the motor-roller-belt-platter system is known and unchanged in time, which is a simplification that causes that the actual rotational speed of the turntable platter controlled by such a regulator differs from the expected one and is in fact unknown.

The turntable speed controller with wireless measurement of the actual rotational speed according to the invention solves these drawbacks. Fig. 1 shows schematically a controller (1) which consists of a radio wave receiver (2), a frequency-adjustable sinusoidal signal generator (5) powering the turntable motor (8), a display module (3) showing the measured rotational speed on minute, the button module (4) for manual modification of the rotational speed setting, the microprocessor (6) controlling all the regulator systems. The regulator is powered from the mains socket.

Fig. 1 shows schematically a belt-driven analog turntable in which the turntable (15) is driven via a belt (7) by an AC synchronous motor (8) powered by a speed controller (1).

Fig. 1 shows schematically the clamp (9) of a gramophone record (12) applied to the spindle of a turntable (14) consisting of a gyroscope module (11) and a radio wave transmitter (10). The clamp is powered by batteries (16).

The rotation of the AC synchronous motor (8) directly depends on the frequency of the voltage supplying the motor. Thus, by regulating the frequency of the supply voltage, the rotational speed of the turntable (15) is also regulated. The rotational speed of the disc (15) depends primarily on the gear ratio resulting from the diameter of the disc (15) and the drive roller (13) of the motor (8). However, the rotational speed of the turntable is influenced by such factors as the type and condition of the drive belt (7) used, belt slip on the motor drive roller (13), which in turn depends on the condition of the turntable platter bearing lubrication, and the degree of wear of individual components of the turntable drive system. The essence of the invention is that the turntable clamp (9) by measuring the actual rotational speed of the turntable (15) and transmitting this information wirelessly to the regulator (1) allows the regulator (1) to automatically correct the frequency of the generator (5) powering the turntable motor (8) in the loop negative feedback in order to obtain the rotational speed of the disc set by the user. This speed is shown in real time on the display (3). The set speed can be changed by the user through the button panel (4) of the regulator (1).

Claims (3)

1. The controller of the rotational speed of an analog turntable platter driven by an AC synchronous motor (8) via a belt (7), containing an electronic gyroscope (11), a radio wave transmitter (10) and an electronic display (3) to present the rotational speed of the platter (15) , characterized in that the electronic gyroscope (11) and the radio wave transmitter (10) are placed in the clamp (9) of the gramophone record (12) mounted on the shaft (14) of the turntable (15), from which information about the current rotational speed of the turntable (15) ) is transmitted by radio to the radio wave receiver (2) connected to the microprocessor (6), to which the microprocessor is also connected to the panel of buttons (4) for manual selection of the stabilized rotational speed of the turntable (15) of the turntable and the generator (5) powering the turntable motor (8). 2. The rotational speed controller of an analog turntable according to claim The method of claim 1, characterized in that the clamp (9) of the record (12) is applied to the tang (14) of the turntable (15) without being permanently connected thereto. 3. The rotational speed controller of an analog turntable according to claim The method of claim 1, characterized in that the generator (5) is an adjustable frequency sinusoidal signal generator. Drawing