SU1485278A1 - Frequency-pulse-width pulse scanning converter - Google Patents

Description

The invention relates to amplifying devices operating in self-oscillation mode with pulse-width signal conversion,

and can be used in analog computing machines. The aim of the invention is to improve the accuracy of work. The frequency-width-pulse scanning converter contains separation transformer 1 with windings 1 <1 ₂ , 1 ₅ , relay element 2, current limiting resistors 3 ... 5, switch 6, frequency divider 7, separation capacitor 8, bus 9 of zero potential, The first and second input buses 10 ,, '102, output 11. The frequency-width-pulse-sweep converter operates in self-oscillation mode, the average value of the output signal is proportional to the resistance connected between the input buses 10 and 10 ₂ , 2 Il.

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The invention relates to amplifying devices operating in the mode of self-oscillations with pulse-width signal conversion, which can be used in analog computers.

The aim of the invention is to improve the accuracy.

Figure 1 shows the functional diagram of the frequency-width-pulse scanning converter; figure 2 - timing charts of signals.

In Fig.1 marked separation transformer 1, the first and second secondary and primary windings 1 ,, 1 _g , C, relay element 2, the first, second and third limiting resistors 3-5, key 6, frequency divider 7, separation capacitor 8, bus 9 zero potential, the first and second input tires 10 ,, G0 ^, output 11, resistance 12 sensor.

FIG. 2 denotes: обознач _χ (ΐ;) is the resistance value of the sensor 12 connected between the first 10 and second 10 ₄ input tin; ΐ ,, - the moments of time of change of resistance of the sensor; + B - switching thresholds of the relay element 2; At ₂ (s) - the output signal of the relay element 2; ^y s (1 :) is the voltage at the first current-limiting resistor 6; 7 _{β & ()} <((;) the output signal of the frequency divider is 7; T _o , T is the sampling interval of the output signal of the relay element 2; ^is the time interval depending on the resistance of the sensor;

- time interval.

The frequency-width-pulse scanning converter operates as follows.

Relay element 2 has symmetrical relatively zero switching thresholds and an inverting hysteresis loop. The output signal of the relay element 2 varies discretely within the FA. The division factor of the frequency divider 7 is 2. The signal at the output of the frequency divider 7 is discretely changed within + A.

The separation capacitor 8 serves to suppress the DC component and prevents the passage of voltage ripples into the input conversion circuit.

Relay element 2 in combination with the first secondary winding C and

The first current-limiting resistor 3 forms a self-oscillating system, the frequency of the output pulses of which depends on the magnitude of the resistance of the sensor 1.2 connected between the cert 10 and the second 10 ₂ input buses. At a sufficiently large value of the sensor resistance (Fig. 2a), the separation transformer 1 on the side of the primary winding C operates in idle mode, therefore its time constant is the greatest, In this case, the frequency of the pulses at the output of the relay element is minimal (Fig. 28 "; AT )

When reducing the resistance of the sensor 12 (Fig.2A) separation transformer 1 goes into short circuit mode and its time constant decreases. As a result, T ₀₂ <T _o , (FIG. 2), since the derivative of the sweep formed on the first current-limiting resistor 3 (FIG. 2) increases.

When the resistance value of the sensor 12 (fig.2e) changes, the frequency divider 7 generates pulses of negative polarity, therefore, the key 7 is open. The rate of increase of the signal on the first current-limiting resistor 3 (figure 3 "p in two mating" half-cycles "sweep conversion is determined by the resistance of the sensor 12. After changing the sign of the output signal of the frequency divider 7 (Figure 2e), key 6 is closed (Figure 2.zh), providing an isolation transformer of short-circuit mode 1 by connecting the second secondary winding ₄ 1 to the second current-limiting resistor 4 · low resistance value, the first derivative of the signal at the current limiting resistor 3 r zko increases (figure 2 ^), and the time interval corresponding to the two subsequent "half-cycles" of conversion is almost independent of the resistance value of sensor 12. Subsequently, as the resistance of sensor 12 decreases (figure 2g), the interval, [Κχ *] decreases (figure 2 ^) and in the limit, when the resistance of sensor 12 becomes zero, condition C, [k *] T * is satisfied. Thus, the average value of the output signal

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1I is proportional to the resistance value of the sensor 12.

The frequency-width-pulse scanning converter is character- <. It is tested for increased work accuracy due to increased speed.

Claims (1)

Claims u The frequency-width-pulse scanning converter containing an isolation transformer, a relay element, to the input of which 15 keys are supplied the first terminal of the first current-limiting resistor and the first terminal of the first secondary winding of the isolation transformer, the second terminal of which is connected to the output of the relay element, the first terminal the second secondary winding of the isolation transformer is connected to the * first output of the second current-limiting resistor, the second output of which is connected via a key ι to the pale-yellow bus potential connected to the second output of the first current-limiting resistor, the third current-limiting resistor, the first output of the primary winding of the isolation transformer is the first input bus of the converter, which means that, in order to improve accuracy, a divider is introduced into it frequency and separator condo sator, and the output of the relay element is connected to the input of the frequency divider. the output of which is the output of the converter and is connected to the control input of the key, the second output of the second secondary winding of the isolation transformer is connected to the zero potential bus, the second output of the primary winding of the isolation transformer is connected to the first lining of the separation capacitor through the third limiting resistor converter. 1485278