SU50418A1 - Oscillographic wattmeter to measure instantaneous power - Google Patents

Description

In the known oscillographic wattmeter designs for measuring the instantaneous power, the magnetic circuit of a fixed winding typically contains iron or another ferromagnetic material. The presence of iron leads to the occurrence of errors, namely, fluctuations in sensitivity when changing the shear angle between the currents in the windings, as well as distortion of the recording of the phase angle due to losses in the iron, causing the magnetic current to lag behind the current creating it.

These drawbacks are eliminated in the proposed wattmeter by removing iron or some other ferromagnetic material from its magnetic circuit. The essence of the invention consists in the special form of a fixed coil and the arrangement of a vibrator inside it, which is made, as usual, in the form of a loop of two tensioned parallel threads.

The shape and location of the parts of the device can be better explained with the help of the attached drawing.

The stationary coil / is made of an elongated shape with a cavity in the form of a narrow slit. Inside the coil, a vibrator is placed in the form of a loop made of a thin silver thread 2, fixed at the ends and equipped with a pocket mirror 3 attached with celluloid or shellac. The vibrator is located inside the current coil so that the longitudinal axis of the loop (parallel to the m) passes through the center and coincides with the axis 2, the loop plane coincides with the XZ plane, and the vibrator mirror lies in a plane parallel to the YZ plane. With such a device and the arrangement of the vibrator, it is possible to: record the deflection of the beam reflected from the mirror, although the latter is inside the coil. To adjust the sensitivity and natural frequency of the loop vibrator, through a small roller and spring, it is connected to the screw 4, which allows changing the tension of the threads. In the casing of the device, not shown in the drawing, a hole is made for the glass 5, which transmits a ray of light from the illuminator.

The housing material must be selected according to the requirements of the instrument. To protect against magnetic fields, the housing can be made of iron. If external fields are absent, the casing can be made of non-conductive material to eliminate the harmful effects of iron.

With continuous continuous operation of the device, heat is circulated around the vibrator through the release of heat. Since the moving oil layer blurs the beam of light a little, you need to slow down the movement of oil between the mirror and the glass. This is achieved by installing in the cavity of the roller, above and below the mirror, two partitions.

In the space between the Iimi, the movement of oil will be significantly weakened and even the motor load will not cause deterioration in the operation of the device.

The subject matter of the invention.

An oscillographic wattmeter for measuring instantaneous power, characterized in that, in order to perform it on an electrodynamic system, the fixed part is given a solenoid, elongated in cross section perpendicular to its axis, so that a movable part can be positioned inside it usually in the form of two threads stretched parallel.