SU781893A1 - Sound pick-up tone arm - Google Patents

Description

The invention relates to the accumulation of information, in particular, to means for reproducing the mechanical recording of tonearms.

A sound pickup tonearm with a device for viscous damping of a sound pickup resonance is known, containing two concentric hemispheres, one of which is associated with a toner: one, and the other with an electroplay board. Between the surfaces of the hemispheres is liquid 1.

However, the design of the tonearm does not provide tightness, which leads to a change in the properties of the liquid in time, creates a significant mechanical resistance to movement of the pickup at 20 playback time.

Also known is the phono tonearm, the sensor contents, the electronic control circuit of the actuating electromagnets, the core of which is spread 25 mutually perpendicularly and connected to the pickup lever arm having a counterweight 2.

The shortcoming of this arm is the complexity of the design, which is JQ

in order to take special measures to reduce friction in the bearing for turning the tonearm of the pickup at horizontal speed, and also to use a special electronic circuit to separate the control signal.

The purpose of the invention is to simplify the design of the device while maintaining effective damping of the oscillations of the pick-up tone arm in any plane. . -

The goal is achieved by the fact that the counterweight is connected with the pickup tonearm through the element of flexibility, the electromagnet measles is made in the form of a weight gain, and the electromagnet coils form two pairs, each coil being made as a sensor and connected to an electronic control circuit.

FIG. 1 shows the kinematic scheme of the proposed pickup ton arm} in FIG. 2 is a view A-A in FIG. one; in fig. 3 - connection of one pair of coils to the control circuit.

The sound pickup arm contains head 1 fixed on one arm of lever 2, flexibility element 3, with the help of which counterbalance 4 with a cortex 5 fixed on it, electromagnet is installed on the second end of lever 2. Electromagnet coil 6 electromagnet parted at this end {Lever 2 KecTkb, there is a pair of electromagnet 6 pairs in the electromagnet, in the same end of the lever 2. In this end, {leverage 2 KecTkb reinforced coils of electromagnet 6, so the electromagnet is used in the same end of the lever 2. In this end of {Lever 2 KecTkb reinforced coils of the electromagnet there is a pair of electromagnet parnets of the lever 2. At this end of {Lever 2 KecTkb reinforced coils of the electromagnet there is a pair of electromagnet in the second section 2. In this end, {Lever 2 KecTkb of the coils of the electromagnet 6, sockets of the lever 2. At the same end {of the Lever 2 KecTkb reinforced coils of the electromagnet 2 electromagnet pair, there is in the same end of the lever 2. 2. perpendicular planes, symmetrically with respect to the axis 10 of the core J of the electromagnet. Works as follows: When playing a record that has warping or ekstrentsiTet, there are fluctuations in tonerMa. At the frequency of its own resonance, the amplitude of such oscillations will be maximum and proportional to the quality factor of the resonance. At the same time, due to inertial forces and the presence of a flexibility element in the system, the electromagnet core and the sensor coil connected to the control circuit input 1 are displaced. An emf arises in the coil, proportional to the speed at which the core moves. The signal amplified by the control circuit 11 is fed to the winding of the second coil of this pair. When current flows through the winding of the second coil, an electromagnetic field arises, which causes the electromagnet's measles to oscillate with a frequency of twitching tonearm. The amplitude and phase of the oscillations of the core are determined by the control circuit and are selected from the condition of compensation of the oscillations of the tonerm of the pickup at the frequency of its resonance. The presence of two pairs of coils ensures damping of oscillations.

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Claims (2)

/ xg II / narma in two mutually perpendicular planes. The invention is used in first and upper class electromotive devices. The effect of the use of the invention is to improve the consumer properties of electroplay devices - to increase the reliability of their work by simplifying the design of the elements of the damping of the sound pickup. The invention of the pickup tonearm, comprising a sensor, an electronic control circuit for actuating electromagnets, the core of which are mutually perpendicular and connected to the pickup arm lever, having a counterweight, from which, in order to simplify the design, the counterweight connected; with the pickup tonearm lever through the introduced element of flexibility, measles electromagnet-. the thread is in the form of a counterweight, and the coils of the electromagnet form two pairs, each pair having one coil made in the form of a sensor and connected to an upstream electronic circuit. Sources of information taken into account in the examination 1. US patent No. 2676806; cl. 274-23, 08/27/54. 2. US patent 3623734,. cl. 274-1 R, 30.11.71 (prototype).