SU25992A1 - Device for measuring AC frequency - Google Patents

Description

The present invention relates to a device for measuring the frequency of an alternating current and that for this purpose, a device of the already known tele-type electromagnetic device and a Quincke interferometer are connected in the device.

In FIG. 1 schematically depicts the proposed device; FIG. 2- his appearance.

In the soundproof chamber Q, an electromagnet Af is placed, the core of which is the membrane K connected to the horn R, and the chamber Q connects to a 0-shaped Si tube entering the ends of another U-shaped tube 5h having an acoustic de process. The bends of the tube 52 are fastened with cross-pieces DI Da, through which the rod B is passed, equipped with a ruler with divisions tp. On the crossbar Di, there is a handle P and a pointer t located opposite the divisions of the ruler TP. The current is applied to the terminals z: Z2. The entire device is placed in a casing, in which slot 9 is made for moving the handle /.

The alternating current passing through the electromagnet G causes a membrane oscillation l, whose frequency will be equal to the frequency of the supply current. Sound through the mouthpiece R and tubes 1 and & will reach the deaf

along the paths a, b, c, d, e and along the paths a, f, g, h, d, e. Depending on the length of the Si and S2 tubes, sound waves in, point d will interfere differently. If both paths are equal, then the sound is the most powerful; when you move the tube Sa, it starts to weaken and, finally, when the length of the path a, b, c, d, e becomes less or more than the path a, /, g, h, d, e by the half-wave length, the oscillations will completely die out in the de and the sound will stop. The ruler of TP can be calibrated for the length of the will and then measured directly on the engine t of the magnitude of the latter.

The device can also serve as a device for signaling a change in the frequency of the current. At normal frequency, it is controlled by the disappearance of the sound, and when the number of current periods in the network fluctuates, the sound of the instrument will be observed, indicating an abnormal mode of operation of the generator.

The subject matter of the invention.

1. A device for measuring the frequency of an alternating current based on the principle of oscillations of an air column and consisting of a telephone-type electromagnetic device for passing a measuring current through it and from an air-filled tube,

which may vary, characterized by the fact that the specified tube consists of two {/ -shaped tubes 2, put on one on the other and move one on the other to obtain the appearance of sound interference in the corresponding air columns.

2. The form of execution of the device mentioned in p. 1, characterized in that one of the tubes is equipped with a de auditory process to observe the interference and a line / p to measure the total length of the tubes and graduated at measured frequencies of ac