FI58033B - HORIZONTALAVLAENKNINGSKOPPLING FOR TELEVISIONSMOTTAGARE - Google Patents

Description

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Patent · och registerstyrelsen 'Antokin utitgd oeh uti.tkrHUn publictnd oi. υ (. öu (32) (33) (31) Requested front »» Buglrd priorlttt 21.03 * 72

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) P 2213597.3 (71) International Standard Electric Corporation, 320 Park Avenue, New York,

New York 10022, USA (72) Klaus Reh, Albershausen, Peter Schulz, Esslingen, Germany Federal Republic of Germany (DE) (7 * 0 Oy Kolster Ab (5 * 0 Horizontal deflection for television receivers

The invention relates to a horizontal deflection circuit for television receivers, the coupling essentially comprising a line control part, a switching part and a deflection part and in which the energy input is adjustable and in which the supply connection includes a series connection consisting of a DC voltage source and a charge inductance.

The energy applied to such a horizontal deflection circuit must be adjustable and the appropriate supply circuit consists, for example, of a DC voltage source and a storage inductor (Speicherinductors).

DE-A-1 537 308 discloses a line or horizontal deflection circuit in which a deflection coil for generating a periodic sawtooth current in the corresponding deflection part of the picture tube is connected to the first current branch via a and a parallel diode connected in parallel.

The switch-off of the controlled rectifier takes place with a commutation phenomenon, i.e. a reversing current in a rectifier whose current reversal is initiated by another controllable switch.

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The first controllable switch is further part of a second current branch which, in series with the controllable switch, includes a second current source and an oscillating reactance. The reactance consisting essentially of the coil and the capacitor takes energy from the second power supply at a certain time when the first switch is closed, the energy taken from the second power supply corresponds to the switching losses generated during the deflection period.

However, in the known basic connection described above, it has not yet been taken into account that it is common to connect to the line output stage also a high-voltage transformer necessary for the use of the picture tube.

In this respect, the supplemented connection is described in detail and its mode of operation is described in the trade name publication "RCA-Halbleitertechnik" Nr. AN 3780-8.68 / 1271 d - 11.68.

In this known circuit, which is largely identical to the circuit described first, the high voltage required for the use of the picture tube is produced in such a way that the horizontal return pulse in the step-up transformer is converted to the required voltage and applied to the picture tube via a rectifier. The high voltage transformer is in parallel with the deflection system. Since the energy taken from the high voltage transformer is not constant due to changes in the beam current, the high voltage must be adjusted accordingly due to the resistance of the high voltage source.

This means that the energy applied to the line termination stage must be the same as the already mentioned deflection connection losses plus the energy required to operate the pipe.

It has already been mentioned above that the energy applied to the line power stage is taken into reactance. The output energy is controlled by connecting a capacitor, here a line power stage reset capacitor, to the DC voltage source, via an inductance placed between the DC voltage source and the capacitor, whereby the capacitor is almost in resonance with this inductance. The change in exported energy is achieved by tasting the inductance. This purpose is served by another variable inductance represented by a transducer.

The required size of the control range of such a supply circuit is decisively influenced by the expected fluctuations of the voltage of the DC voltage source. This voltage is derived from the mains voltage.

The disadvantage of the known supply circuit is that the inductances, i. both the charge inductance and the parallel transducer must be chosen to be very large. This can be easily seen by briefly looking at the extreme cases for supply-voltage fluctuations.

When the value of the supply voltage is at the lowest permissible limit, the inductive resistance of the transducer must be so large that the value of the total inductance of the parallel connection is practically determined only by the charge inductance.

However, if the supply voltage value is at the upper limit, then the transducer must have the lowest possible inductive resistance, so that the value of the total inductance of the parallel connection is practically determined only by the transducer.

3,58033

The object of the present invention is to provide a horizontal deflection circuit of said quality which has the simplest possible and low-cost supply circuit, in addition to which at least the control range of the known circuit is maintained.

The horizontal deflection circuit according to the invention is characterized in that a rectifier is connected in series with the DC voltage source and the charge inductance, the output direction of which corresponds to the direction of the supply current, and that a variable inductance is connected in parallel with the rectifier.

Due to the reduction of private elements, this solution also has the advantage that the charge inductance and the commutation coil can be combined in a constructive relationship into a simple structural element.

Other advantages of the invention as well as the operation of the coupling device will become apparent from the following description and the accompanying drawing.

The drawing illustrates a simplified circuit diagram of a horizontal deflection circuit, showing only the elements immediately necessary for an understanding of the invention, in particular the elements of the supply circuit.

The input point 1 has a supply DC voltage Ug derived from the mains voltage, which can vary by approximately _ + 15% depending on the mains voltage variation.

Connected to point 1 is the input inductance of the supply circuit, which essentially consists of a fixed charge inductance 2 and a variable inductance 3 having, for example, the shape of a working winding of a transducer. The inductance of the working winding is controlled by the control current in the control winding of the 1st transducer. The control current 1st is produced in a control circuit (not shown). Such control circuits, including the generation of a control variable, are known, for example, from the publications already mentioned.

A series connection consisting of a commutation winding 9, a commutation capacitor 6 and an actual deflection section 7 is connected to the output of the charge inductance 2, whereby a commutation switch 5 is connected in parallel with this series connection.

Terminal 10 schematically indicates that the high voltage generation voltage is also connected to the horizontal deflection end stage.

When the commutation switch 5 is closed, the sawtooth-like rising current flows from point 1 through the rectifier 4 connected in the discharge direction, through the charge inductance 2 and the commutation switch 5 to ground (to the body).

In this case, an amount of energy is charged to the charge inductance 2, which is known to be (l / 2) Li ^.

When the switch 5 is opened, current flows from the charge inductance 2 to the commutator capacitor 6, whereby the energy charged to the charge inductance is partially transferred to this capacitor.

The charge inductor 2 and the commutation capacitor 6 are an oscillating structure: as a result, after a certain time, the energy exchange takes place in the opposite direction, i.e. the commutation capacitor B also supplies energy to the charge inductor 58033 dance 2, as explained below, also back to the network.

Inductance 9 can be excluded in this context.

The energy supply to the network can now be controlled by the inductance-adjustable part 3 of the entire inductance at the input of the circuit, because in this direction of the current the diode 4 is in the blocking direction.

With this control, the residual energy remaining in the commutation capacitor 6 can always be kept constant at the time of reclosing of the commutation switch 5.

However, this means that the amplitude of the deflection current will be made independent of the mains voltage fluctuations, because the amplitude of the deflection current depends exclusively on the energy in the commutation capacitor 6 at the above-mentioned time.

The fact that here the charge inductance 2 and the variable inductance 3 are quotient in series is that the effect of the change in resistance of the component, here the inductance of the coil 3, is substantially stronger on the overall behavior than can be in a known parallel connection. This means that the same necessary adjustment range can be achieved with fewer means. The function of the capacitor 8 is to determine the operating point of the diode 4 and it also acts as an additional energy accumulator.

In practice, another advantage is obtained. If the energy analysis presented in the introduction is performed in the practical example, then it turns out that the energy supplied to the input inductance in the case of series connection is less than one third of the energy in parallel connection. As the energy accumulators also have an ohmic resistance to be taken into account, the loss-power in series connection is, of course, also considerably lower and the amount of heat dissipated is thus lower. This is especially important when the packaging density of the equipment is high.