HU205510B - Parallel coupler for central voice frequency control system - Google Patents

Abstract

According to the invention, the coupling transformer (TCS) coupling factor is between 0.5 and 0.85, the first capacitor (Cl) is coupled to the transmitter (A) by means of a serial first switch (KI) and low-voltage winding of the transformer (TCS). L1) and the second switch (K2) with the first capacitor (Cl) are connected in parallel. (Figure 3) EN 205 510 B Scope of the description: 6 pages (including 2 sheets)

Description

The present invention relates to a parallel coupling apparatus for a central audio frequency control system.

The central voice control system is used for the central switching on and off of communal or market consumers, which can either be periodically shut off from the electricity service without damage (pL water heaters, heat storage ovens) or according to a specific program. to be turned on (eg public lighting).

The control is a coded sequence of signals generated by central automation. by telegram. The signaling channel itself is the power supply network that supplies the consumer equipment. The telegram consists of a series of audio-frequency (110-600 Hz) voltage signals and pauses produced by high-power general-purpose three-phase electronic transmitters for power supply to the mains up to a nominal voltage of 1000 V. The connection between the transmitter and the power transmission network to be supplied is provided by the coupling devices.

The function of the coupling devices is to transform the signal to be supplied to the power network at a given point to the appropriate voltage level and to minimize the loss, to galvanically separate the high voltage power network from the transmitter and protect the transmitter at the industrial frequency (eg 50 Hz). currents and voltages generated by the device, and stresses caused by disturbances in the network (short circuits, overvoltages, etc.).

During pauses in transmission, the coupling device is disconnected from the transmitter and thus acts as a passive filter. Suitably, it is possible for the disconnected coupling device to protect the transmitter network portion of the transmitter from interference or to favorably influence its audio frequency parameters (suction loop or close loop mode).

There are two basic types of coupling devices: serial and parallel. In a serial coupler, the audio frequency signal is magnetic, while in a parallel coupler, it is capacitively coupled to the power network.

The general structure of the parallel couplers is shown in Figure 1. For the high voltage (H) network represented by the complex audio frequency (ZH) impedance in the drawing, the voltage level (UH) required by the network (H) is generated by the audio coupling transformer (T) from the audio frequency (UA) signal of transmitter (A). The low-voltage winding of the transformer (T) is connected to the transmitter (A) through filters (SZ) and its high-voltage winding capacitively couples the audio signal to the network (H) via a serial coupling capacitor (C) and a series capacitor 50 Hz to transmitter (A). The inductance (L) absorbs the sound frequency reactive power produced by the capacitor (C). The function of the filter circuit (SZ) is to filter the harmonics of the square signals produced by the transmitter (A), to reduce the effects of the impedance matching and the power current CH) on the transmitter (A).

A known embodiment of parallel coupling devices is shown in the wiring diagram illustrated in FIG. Here, the high voltage (L2) winding of the (M) mutual inductance (TCS) transformer also serves as the compensating inductor, the capacitor (C2) serves as the coupling capacitor, and the capacitor (C1) replaces the filter circuit.

Parallel couplers are of two types, depending on the type of transformer used. If the magnetic coupling between the two windings of the (TCS) transformer (L1 and L2) is very loose (coupling factor k <1), the coupling device is called loose coupling if the magnetic coupling is tight (k = 1), rigid coupling.

A characteristic of both solutions is that the serial frequency oscillation tuned to the transmit frequency is formed by the high voltage (L2) winding of the (TCS) transformer and the capacitor (C2). Thus, during the interruption of transmissions when the circuit is interrupted by the transmitting device (A), the coupling device behaves as a low-impedance suction loop for foreign transmissions. This has the disadvantage of known solutions: if the suction circuit effect is undesirable, the coupling device must also be disconnected on the high voltage side.

A loose coupling solution is described in DE-B2-24 59 978. in U.S. Pat. This is usually used for load-controlled transmitters (A), where the operating condition is that the transmitting device (A) is always loaded with capacitive current regardless of the phase angle of the generally inductive (H) network. This is achieved by using the capacitor (Cl) to severely overcompensate the need for network (H). In case of loose coupling, the (TCS) transformer is air-core, so due to the large spreading areas, it can only be made in a single phase design. Thus, for three-phase feeds, the space requirement is relatively high. It cannot be built into a metal cabinet for outdoor use, but can only be enclosed with a special plastic case. The advantage, however, is that the phases are independent, so tuning is easy. A further disadvantage of a loose coupling is that its loss is generally greater than that of a rigid coupling, since air core coils cannot be made with a quality factor greater than 40-60.

A rigid coupling solution is disclosed in DE-A128 30 151. in U.S. Pat. This is usually used for forced-commutation controlled (A) transmitters where overcompensation of the network inductance is unnecessary. The air gaps of the rigid coupling (TCS) transformer can be made in iron core, such as three-phase, and have less loss than loose coupling. However, the disadvantage is that the construction of the gaps in the iron core requires a high level of manufacturing precision and a particular problem is the reduction of the noise of the iron core under the influence of sound frequency. The

Therefore, the tuning of the apparatus is further disadvantageous because, due to the scattering magnetic coupling, either the coupling capacitor (C2) or the filter circuit In the event of a failure of the (Cl) capacitor, the coupling device will have relatively large currents of 50 Hz, to which the coupler must be dimensioned.

The object of the present invention was to provide an olive oil shuffle that provides a simple means to enable or disable the suction effect during intermission between broadcasts and which can be manufactured at a lower cost.

The invention thus provides a parallel coupling device for a central audio frequency control system, which low-voltage winding of a coupling transformer, through a serial adapter first capacitor, to an audio device generating a frequency response, and a high-frequency winding through a serial coupler. The invention is characterized in that the coupling transformer has a coupling factor of between 0.5 and 0.85, the first capacitor is connected to the transmitter by a serial first switch, and a second switch is connected in parallel with the low-voltage winding of the transformer and the first capacitor.

By using the switches of the present invention, the suction loop effect can be simply switched on and off during the pauses between the transmissions. The "semi-rigid" design of the transformer - that is, the choice of coupling factor (k) between 0.5 and 0.85 allows three-phase design, easy tuning per phase and outdoor installation in a metal cabinet.

In a preferred embodiment of the invention, a vibration circuit consisting of a series inductance with a first capacitor and a third capacitor tuned to the transmit frequency of the transmitter is connected in series. In this way, a second resonance frequency other than the transmit frequency can be set. This effect can also be achieved by having a series inductance connected in series with the first capacitor. The series inductance is preferably configured as a low-voltage winding in the transformer, but is magnetically independent of the winding.

The invention will now be described with reference to the preferred embodiments shown in the drawings, wherein: *

Figures 1 and 2 show a schematic diagram of a known coupling device, a

3-6. Figures 3 to 5 are schematic diagrams of a preferred embodiment of a coupling device according to the invention.

In the drawings, like reference numerals denote elements having the same or same function.

3, the transmitting apparatus (A) is coupled via a switch (OFF) and an adjustable capacitor (C1) to low-voltage (L1) winding of the coupling transformer (TCS). Switch (K2) is connected in parallel with transmitter (A) and switch (K1). The adjustable high voltage (L2) winding of the (M) mutual inductance (TCS) transformer is connected via a series (C2) capacitor to the complex audio frequency (ZH) impedance representing the high voltage power supply network.

The coupling device can be connected to the desired audio frequency, e.g. 216.67 Hz can be tuned by adjusting the coil (L2) and adjusting the capacitor (Cl). The coil (L2) causes coarse tuning, but its variation affects the mutual inductance (M) and thus the amplitude that can be adjusted by the capacitor (Cl). However, adjusting the capacitor (Cl) affects tuning, so tuning is an iterative process.

When transmitting, switch (OFF) is closed and switch (K2) is open. During transmission pause, switch (OFF) is open and switch (K2) is normally closed. Thereby, during a pause, the entire coupler for the network forms a serial oscillation circuit tuned to the audio frequency. That is, when the circuit is cut at points (D) and (E), the imaginary part of the impedance measured from points (e) is approximately zero. Therefore, the value of each element must be selected so that, at the given voltage of the transmitter (A), the desired voltage is displayed at the network impedance (ZH) taken into account in the design. Contrary to known solutions, where the coupling device is tuned to the given audio frequency during the broadcast pause and is tuned to a small extent (e.g., 15%) during transmission, the coupling device according to the present invention is precisely tuned to the is tuned to a specific frequency.

In the present invention, the suction loop effect can be easily bypassed by opening the low voltage switch (K2), since the coupling device is tuned. This is e.g. may be needed if there are two or more transmitters in the network, e.g. for reserve purposes. Contrary to known solutions, to eliminate the suction loop effect, the coupling device does not need to be disconnected from the mains, which is an overvoltage operation due to interruption of capacitive currents. In this mode, the coupling device acts as a capacitor and can be used as a phase correction capacitor.

The (TCS) transformer according to the invention is of "semi-rigid" design, i.e. the coupling factor of (k) is between 0.5 and 0.85. This makes the (TCS) transformer cheaper, since it does not require the use of iron core cores which require precise manufacturing technology. The transformer can be manufactured in a three-phase design, placed outdoors in a conventional iron cabinet and, since the three phases of the transformer are virtually independent, the coupling groove can be easily tuned in phase.

The coupling device shown in Figure 4 differs from that shown in Figure 3 in that the transmitting device (A) is of series (LSZ) inductance and (CSZ) capacitor3.

The 205 510 Β oscillating circuit tuned to the transmit frequency is connected in series. This allows the coupler to set a second resonance frequency other than the transmit frequency, and to filter the harmonics of the square signals of the transmitter (A) more effectively.

In the coupling device illustrated in Fig. 5, the oscillation circuit of Fig. 4 is configured such that the capacitors (CSZ) and (Cl) are connected in series with the capacitor (CE) corresponding to their serial output, and this serial oscillation circuit is inserted between the OKI) switch and the (Ll) winding.

The coupling device shown in Figure 6 differs therein

4 shows that instead of capacitor (C1), a voltage divider consisting of (C1l) and (C12) capacitors is inserted, where (Cll = b.Cl and C12 = (lb) .Cl). b = will decrease in Cll / Cl without changing the degree of tuning.

Claims (6)

PATENT CLAIMS 1. A parallel coupling device for a central audio frequency control system, wherein the low voltage winding of a coupling transformer through a serial interface first capacitor to a transmitting device generating a frequency signal is connected to a high-voltage network by transducing a high voltage, Between 0.5 and 0.85, the first capacitor (Cl) is connected to the transmitter (A) via a serial first switch (OFF), and a low switch coil (L1) of the transformer (TCS) and a second switch with the first capacitor (Cl) (K2) is connected in parallel. Apparatus according to claim 1, characterized in that a vibrating circuit consisting of a series inductance (LSZ) and a third capacitor (CSZ) tuned to the transmission frequency of the transmitter (A) is connected in series with the first capacitor (Cl). Apparatus according to claim 1, characterized in that the first capacitor (CE) is connected in series with an inductance (LSZ). 4. Device according to any one of claims 1 to 3, characterized in that a fourth capacitor (C12) is connected in parallel with the low voltage winding (L1) of the transformer (TCS). 5. Device according to any one of claims 1 to 3, characterized in that the transformer (TCS) has a coupling factor of between 0.7 and 0.8. Apparatus according to claim 2 or 3, characterized in that the serial inductance (LSZ) in the transformer (TCS) is designed as a series-connected but magnetically independent winding by its low-voltage winding (L1).