SU445145A1 - DC / DC converter - Google Patents

Description

one

This invention relates to the measurement of large currents.

DC / DC converters B are known as a digital code for measuring and controlling large DC currents,

containing a current sensor, sawtooth generator, null organ, control trigger, AND circuit, pulse generator n pulse counter with decoder and display unit, the first current sensor input connected to the operating current source and its OUTPUT connected with the first INPUT of the control trigger, the second input of which is connected to the starting pulse, the first OUTPUT through the sawtooth generator is connected to the second input of the current sensor, and the second output through the AND circuit, the second INPUT of which is connected to the output g pulse generator, the counter through the decoder is connected to the input of the display unit.

Such converters are built on the basis of an accurate niloil voltage generator, with the subsequent conversion of a sawtooth voltage into a powerful sawtooth current.

However, these converters have insufficient accuracy due to the large nonlinearity of a high-power DC amplifier.

2

The purpose of the invention is to improve the accuracy of the conversion.

This goal is achieved by introducing a correction trigger into the converter, shifting the register, switch, coincidence circuit, and correction counter, the decoder output being connected through the shift register with the first G switch INPUT and the first input of the correction trigger, the second input of which is connected to the first input of the counter switch and OUTPUT switch, its first OUTPUT through a coincidence circuit, the second input of which is connected to the output of the pulse generator, and the correction counter is connected to the second input of the switch, and the second to third to the input of the “I.

The drawing shows a block diagram of the device.

The converter contains current sensor 1, null organ 2, sawtooth voltage generator 3, control trigger 4, AND circuit 5, pulse counter 6, decoder 7, display unit 8, pulse generator 9, trigger

10, a shift register 11, a correction counter 12, a matching circuit 13, a switch 14, a bus 15 with an operating current, and a bus 16 for a conversion start pulse. The operation of the device is based on the effect.

comparing the magnetic fields generated by the operating current and the linearly varying compensating current.

In the initial state, the sensor 1, which has a working, signaling and compensating windings, is saturated with a magnetic field created by the operating current of the field 15. the control trigger 4 disables, and the correction trigger 10 permits the impulses of the generator 9 to pass through the circuit "And 5. The coincidence circuit 13 is closed by a signal correction trigger 10, the shift register 11 is in the zero state. The measurement start pulse includes a control trigger 4, which permits the passage of generator 9 pulses through an AND 5 circuit to the input of pulse counter 6 and a sawtooth voltage generator 3, the current of which, flowing through the sensor I compensation winding, creates a magnetic field opposite to the operating current field . When the time I reaches, when the error due to the nonlinearity of the generator 3 of the filament voltage is a certain amount, the signal from the output of the decoder 7 activates the correction trigger 10, which prohibits the flow of pulses to the input of the counter 6 and allows the signals to enter the correction counter 12. At the same time, the signal from the output of the decoder 7 translates the shifting register I from the state “O to the state” 1, the latter prepares the switch 14 to receive the signal from the counter 12 correction. The signal of the correction counter 12 via the switch 14 enters the correction trigger trigger 10 and sets it to its initial state.

The pulses from the generator 9 are fed to the input of the counter 6, the coincidence circuit 13 is closed, the correction counter 12 is reset to the state "O." At time / 2, the correction cycle is repeated, only the shift register 11 enters the state "2, etc." This happens until the magnetic fields in sensor 1 are not matched. At the moment of equality of the magnetic fields in the sensor due to the operating current of the bus 15 and the generator sawtooth 3 compensating it, the null organ 2 generates a pulse returning the control trigger 4 to the initial state. The display unit 8 fixes

a number proportional to the value of the operating current PINA 15.

The device provides higher conversion accuracy by correcting the non-linearity of the sawtooth generator and significantly reduces the requirements for the DC amplifier on which the generator is based.

A current transducer built according to the proposed scheme can be used in instruments for measuring and controlling large currents, as well as in automated control systems for complex electrophysical installations.

Subject invention

A DC converter to a digital code containing a current sensor, a sawtooth generator, a null organ, a control trigger, an AND circuit, a pulse generator and a pulse counter with a decoder and a display unit, the first current sensor input connected to an operating source TO and its output through the null organ is connected to

the first control trigger input, the second input of which is connected to the starting pulse, the first output is connected to the second input through the sawtooth generator

current sensor, and the second output through the circuit "And, the second input of which is connected to the output of the pulse generator, the counter through the decoder is connected to the input of the display unit, characterized in that, in order to increase the conversion accuracy, a correction trigger, a shift register, switch , a matching circuit and a correction counter, the decoder output being connected via a shift register to the first input of the switch and to the first input of the correction trigger, the second input of which is connected to the first input of the correction counter and the output of the switch, its first output through the coincidence circuit, the second

the input of which is connected to the output of the pulse generator, and the correction counter is connected to the second input of the switch, and the second to the third input of the “I.

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