RU2699590C1 - Two-phase harmonic signal generator - Google Patents

Abstract

FIELD: radio engineering and communication.

SUBSTANCE: invention relates to the field of radio engineering, in particular can be used for generation of harmonic excitation signals of sine and cosine windings of rotating transformers. Two-phase harmonic signal generator comprises a flip-flop, an inverter, a pulsed sequence generator, first and second adders, first, second, third and fourth active low-pass filters of the second order, first and second power amplifiers, a current limiter unit.

EFFECT: technical result consists in improvement of reliability due to high degree of resistance to external factors, as well as providing identity of electrical characteristics of sine and cosine generator signals.

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Description

The invention relates to the field of radio engineering, in particular, can be used to generate harmonic excitation signals of rotating transformers.

Known two-phase generator of harmonic signals (AS No. 1084941 priority from 09/11/1981, "Two-phase generator of harmonic signals", authors: Kolbin VA, Korepanov AG, IPC Н03В 27/00, published on 04/07/1984 bul No. 13), containing a multivibrator and a pulse distributor connected in series, a key block, a low-pass filter, an additional key block and a low-pass filter, a multi-level source of constant voltage. The first, second, ..., n outputs of the pulse distributor are connected respectively to the first, second, ..., n control inputs of the key block and the additional key block. The output of the key block is connected to the input of the low-pass filter. The output of the additional key block is connected to the input of the additional low-pass filter. The first, second, ..., n signal inputs of the key block are connected respectively to the first, second, ..., n outputs of a multilevel constant voltage source. The first, second, ..., n signal inputs of the additional key block are connected respectively to k, k + 1, ..., k + n outputs of a multilevel source of constant voltage, where k = ϕn / 2π, (ϕ is the phase shift between the output signals, 2π / n is the sampling step of the harmonic signal, n is any number. To increase the accuracy of the formation of the harmonic signal, it is necessary to increase the number of approximation levels, and therefore the step n. For a shift by π / 2, you can choose n = 8, 12, 16, ... and etc. This device is selected as the closest analogue to the claimed image shade.

The disadvantages of the known two-phase harmonic signal generator are:

- the use of a large number of keys (at least 16 keys in two blocks is required for phase shift between the output signals by π / 2) and a multi-level source of constant voltage reduces reliability and increases weight and size characteristics;

- for the formation of output harmonic signals, the use of a multi-level source of constant voltage with at least five reference values is required (if step n = 8 is selected);

- the uncertainty of the state of the output signals after turning on the power and until the establishment of the supply voltage to the nominal value;

- in the description of the known generator there is no information about the type (active / passive) and the order of the low-pass filters. Since there is no reservation about the active type, most likely, passive low-pass filters are implied, at least 3-4 orders of magnitude (or two series-order low-pass filters of 2 orders at each output). A passive low-pass filters of 3-4 orders (or two series-connected low-pass filters of 2 orders) repeatedly reduce the voltage amplitude of the signals generated at the outputs of the key blocks. In addition, a passive low-pass filter of 3-4 orders of magnitude is difficult to configure its amplitude-frequency characteristics. If active low-pass filters are used (as well, at least 3-4 orders of magnitude), then the implementation of the circuit of this device becomes unreasonably redundant in terms of the number of active components: a source with five, at least, reference values of constant voltage, at least sixteen keys plus two active low-pass filters of 3-4 orders (or four active low-pass filters of 2 orders).

The technical problem to which the invention is directed is to create a generator with the following characteristics:

- generating two (sine and cosine) identical output harmonic signals, phase shifted relative to each other by 90 ° with a high degree of accuracy;

- requiring a constant voltage source for generating output harmonic signals with no more than 2 reference values;

- generating two harmonic signals (sine and cosine) with a given value of the amplitude of the output voltages and a small value of the difference between them;

- consisting of a minimum amount of ERA (electro-radio products) based on semiconductors;

- consisting of a minimum number of analog nodes and their active EREs;

- providing a high degree of identity and stability. electrical characteristics of the sine and cosine signals when the ambient temperature changes over the entire range of operating temperatures;

- maintains operability with predetermined electrical characteristics under conditions of exposure to WWF (external factors) with high values of the characteristics of the impact.

The technical results to which the invention is directed are to increase reliability, reduce weight and size characteristics, provide a high degree of resistance to WWF, ensure accuracy, stability and identity of the electrical characteristics of the sine and cosine signals of the generator.

These technical results are achieved by the fact that in a two-phase harmonic signal generator containing the first and second low-pass filters, it is new that the first and second adders, the third and fourth low-pass filters are additionally introduced, and each filter is made in the form of an active low-pass filter , a block of current limiters, first and second power amplifiers, the outputs of which are respectively the first and second outputs of a two-phase harmonic signal generator, a pulse shaper Inverter, trigger, the first and second control inputs of which are the first and second inputs of the two-phase harmonic signal generator, respectively, and the first, second, third and fourth outputs of the trigger are connected respectively to the first, second, third and fourth inputs of the pulse train and the first, the second, third and fourth inputs of the inverter, the first, second, third and fourth outputs of which are connected respectively to the fifth, sixth, seventh and eighth inputs of the pulse shaper sequences, the eighth input is connected to the first input of the trigger, the second, third and fourth inputs of which are connected respectively to the first, second and third inputs of the pulse sequence generator, the first group of outputs of which is connected to the group of inputs of the first adder, the output of which is connected to series-connected first a low-pass filter, a third low-pass filter and a first power amplifier, and the second group of outputs is connected to the group of inputs of the second adder, the output of which it is single with a second low-pass filter, a fourth low-pass filter and a second power amplifier connected in series, while the group of power inputs of each adder, low-pass filter, power amplifier is connected to the corresponding group of outputs of the current limiter unit, the inputs of which are power inputs of a two-phase harmonic signal generator moreover, each of the pairs formed by the first and second low-pass filters, the third and fourth low-pass filters, the first and second adders, on the corresponding dual operational amplifier.

The implementation of the first and second adders, as well as the first / second and third / fourth low-pass filters on dual operational amplifiers ensures the identity of the dependence of the electrical characteristics of the sine and cosine signals of a two-phase harmonic signal generator from changes in ambient temperature. The use of a block of current limiters prevents their breakdown during exposure to WWF, which increases the reliability of the generator and its resistance to WWF.

The circuitry implementation of the claimed device allows for the formation of output harmonic signals to get by with a constant voltage source with only two reference values, and also reduces the number of active active EMIs, which increases the reliability of the generator and reduces its overall dimensions.

Due to the use of precision resistors and capacitors with small values of the temperature coefficient of resistance and the temperature coefficient of capacitance in adders and low-pass filters, respectively, it additionally provides a high degree of accuracy, stability and identity of the electrical characteristics of the sine and cosine signals of a two-phase harmonic signal generator.

In FIG. 1 is a functional diagram of a two-phase harmonic signal generator; FIG. Figure 2 shows the diagrams of the trigger output signals, where A, B, C, D are pulse signals at the first, second, third, and fourth outputs of the trigger, respectively. In FIG. 3 shows diagrams of pulse sequences generated by the pulse generator; FIG. 4 is a diagram of quasi-harmonic signals QSIN1, QCOS1, in FIG. 5 is a diagram of quasi-harmonic signals QSIN2 and QCOS2, in FIG. 6 - diagrams of output signals Sin, Cos.

The two-phase harmonic signal generator (Fig. 1) contains a trigger 1, an inverter 2, a pulse shaper 3, the first 4 and second 5 adders, the first 6, second 7, third 8 and fourth 9 active low-pass filters of the second order (hereinafter - low-pass filter), the first 10 and second 11 power amplifiers, block 12 current limiters.

The first and second control inputs of trigger 1 are respectively the first and second inputs of a two-phase harmonic signal generator. The first, second, third and fourth outputs of trigger 1 are connected respectively to the first, second, third and fourth inputs of the pulse shaper 3 and the first, second, third and fourth inputs of inverter 2. The first, second, third and fourth outputs of inverter 2 are connected respectively to fifth, sixth, seventh and eighth inputs of the shaper 3 pulse sequences. The eighth input of the pulse shaper 3 is connected to the first input of the trigger 1, the second, third and fourth inputs of which are connected respectively with the first, second and third inputs of the shaper 3 of the pulse sequences. The first group of outputs of the pulse shaper 3 is connected to the group of inputs of the first adder 4. The output of the first adder 4 is connected to the first low-pass filter 6, the third low-pass filter 8, and the first power amplifier 10. A second group of outputs of the pulse shaper 3 is connected to a group of strokes of the second adder 5. The output of the second adder 5 is connected to a second low-pass filter 7, a fourth low-pass filter 9, and a second power amplifier 11 connected in series. The group of power inputs of each adder 4 (5), low-pass filter 6 (7, 8, 9), power amplifier 10 (11) is connected to the corresponding group of outputs of the current limiter unit 12, the inputs of which are power inputs of a two-phase harmonic signal generator.

All three logical nodes of a two-phase harmonic signal generator (trigger 1, inverter 2, and pulse shaper 3) are performed on a digital base matrix chip (BMC).

Adders 4 and 5 are performed on a dual operational amplifier (op amp). Signals SIN1, SIN2 and COS1, COS2 are connected to the direct inputs of operational amplifiers of adders 4 and 5, respectively, via summing resistors, and to inverse inputs, signals SIN3, SIN4, and COS3, COS4 are also connected through summing resistors (not shown in Fig. 1).

Pairs of active low-pass filters 6, 7 and 8, 9 on a non-inverting frequency-dependent negative resistance are performed on dual op amps, respectively.

All resistors and capacitors used in the nodes of the adders 4, 5 and low-pass filters 6, 7, 8, 9 must be precision and with small values of the temperature coefficient of resistance and the temperature coefficient of capacitance, respectively.

Power amplifiers 10, 11 are performed on complementary pairs of transistors.

Block 12 current limiters perform on current-limiting resistors, which are included in the power supply circuit of all op-amps and in the collector circuit of all transistors. Block 12 current limiters is designed to prevent breakdown of the op-amp and transistors during exposure to WWF.

A two-phase harmonic signal generator operates as follows.

After the external power supply of the two-phase harmonic signal generator is turned on, an external single rectangular pulse signal RES is applied to its first input, which sets trigger 1 to its initial state (a logic zero voltage level is set at each output of trigger 1) and holds it in this state until the external reference voltages U1, U2 to rated values.

External clocked rectangular pulses CLK with a repetition rate F _IN are supplied to the second input of a two-phase harmonic signal generator. After the end of the action of the RES signal, trigger 1 enters the operating mode and at each of its outputs, pulses with a repetition rate F _IN / 8 are formed under the action of clock pulses CLK. In this case, a pulse is formed at each output of trigger 1, which is shifted in phase relative to the pulse of the previous output of trigger 1 by 1/8 of its period. The diagrams of the output pulse signals of trigger 1 are shown in FIG. 2.

The output signals from trigger 1 are fed to the inputs of inverter 2 and to the first, second, third and fourth inputs of the pulse shaper 3. The output signals from the inverter 2 are supplied to the fifth, sixth, seventh and eighth inputs of the pulse shaper 3. At all outputs of the pulse train generator 3, signals with a repetition rate of F _IN / 8 are generated, the diagrams of which are shown in FIG. 3.

The signals at the outputs of the shaper 3 pulse sequences are generated according to the following algorithms: SIN1 = I & II, SIN2 = III & VIII, SIN3 = V & VI, SIN4 = IV & VII, COS1 = III & IV, COS2 = II & V, COS3 = VII & VIII, COS4 = I & VI,

where I, II, III, IV, V, VI, VII, VIII signals at the first, second, third, fourth, fifth, sixth, seventh and eighth inputs of the shaper 3 pulse sequences, respectively.

The output signals SINI, SIN2, SIN3, SIN4 from the first group of outputs of the pulse shaper 3 are supplied to the inputs of the first adder 4, and the signals COS1, COS2, COS3, COS4 from the second group of outputs to the inputs of the second adder 5. At the outputs of the first 4 and second 5 adders form identical quasiharmonic signals of the first level of approximation QSIN1 and QCOS1, shifted in phase relative to each other by 90 °. The diagrams of quasi-harmonic signals QSIN1, QCOS1 are shown in FIG. four.

The quasi-harmonic signals QSIN1, QCOS1 are fed to the inputs of the first 6 and second 7 low-pass filters, respectively. At the outputs of the low-pass filters 6, 7, identical quasiharmonic signals of the second approximation level QSIN2 and QCOS2 are formed, 90 ° out of phase with respect to each other. The diagrams of quasi-harmonic signals QSIN2 and QCOS2 are shown in FIG. 5.

The quasi-harmonic signals QSIN2 and QCOS2 are fed to the inputs of the third 8 and fourth 9 low-pass filters, respectively. At the outputs of the low-pass filters 8, 9, identical harmonic signals SIN and COS are formed, 90 ° out of phase with respect to each other.

The generated harmonic signals SIN and COS are fed to the inputs of the first 10 and second 11 power amplifiers, which amplify the incoming signals to the current amplitude levels required by the load. The outputs of the first 10 and second 11 power amplifiers produce harmonic signals (see Fig. 6) Sin and Cos with a frequency of FIN / 8, phase shifted 90 ° relative to each other.

Block 12 current limiters limits the currents flowing in the adders 4 and 5, active low-pass filters 6, 7, 8, 9 and power amplifiers 10, 11 during exposure to WWF, preventing their breakdown.

Claims (1)

A two-phase harmonic signal generator containing the first and second low-pass filters, characterized in that the first and second adders, the third and fourth low-pass filters are additionally introduced, each filter made in the form of an active low-pass filter, a block of current limiters, the first and second amplifiers power, the outputs of which are respectively the first and second outputs of a two-phase harmonic signal generator, pulse shaper, inverter, trigger, first and second control whose inputs are respectively the first and second inputs of a two-phase harmonic signal generator, and the first, second, third and fourth outputs of the trigger are connected respectively to the first, second, third and fourth inputs of the pulse train and the first, second, third and fourth inputs of the inverter, the first , the second, third and fourth outputs of which are connected respectively to the fifth, sixth, seventh and eighth inputs of the pulse shaper, while the eighth input is connected to the first trigger input, the second, third and fourth inputs of which are connected respectively to the first, second and third inputs of the pulse shaper, the first group of outputs of which is connected to the group of inputs of the first adder, the output of which is connected to the first low-pass filter, the third low-pass filter and the first power amplifier, and the second group of outputs is connected to the group of inputs of the second adder, the output of which is connected to the second filter in series lower frequencies, a fourth low-pass filter and a second power amplifier, while the group of power inputs of each adder, low-pass filter, power amplifier is connected to the corresponding group of outputs of the current limiter unit, the inputs of which are power inputs of a two-phase harmonic signal generator, each of which formed by the first and second low-pass filters, the third and fourth low-pass filters, the first and second adders, is made on the corresponding dual operational amplifier .

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