SU1243073A1 - A.c.voltage-to-d.c.voltage instrument transducer - Google Patents

Abstract

The invention relates to electrical measuring technique and can be used to convert the amplitude value of a variable input periodic voltage to a constant output in a predetermined time interval. The purpose of the invention is to increase speed and accuracy. The transmitter contains rectifiers 1, 2 connected to the secondary winding of a transformer 3, a filter capacitor 5, a constant voltage source 7. resistor adder (PC) 9 and a sequence circuit of resistor 12 and transistor 11 connected in parallel to the output of the rectifier 1 and capacitor 5. Source 7 is connected between one output terminal 4 formed by the middle terminal of the secondary winding of the transformer 3 and input 8 PC 9. The input 10 of PC 9 is connected to the output of an output terminal 2. The output of PC 9 is connected to the base of the transistor 11, which acts as an electronic switch. The introduction of constant voltage source 7, PC 9 and electronic key II weakens the effect of impulse noise on the amplitude value of the output voltage by integrating them into the circuitry of the device. The speed is increased by ensuring that the discharge time of the capacitor 5 is dependent on the magnitude of the input voltage. Introducing the output circuit 1 of the resistor 13 into the output circuit allows one to convert rectangular periodic voltage pulses with a pause at zero. 1 hp f-ly, 3 silt; c (L N3 4 CO o | Od fi., 1

Description

The invention relates to electrical measuring technology and can serve to convert the amplitude value of a variable input periodic voltage to an output output in cases where the output value information is measured at a predetermined time interval.

The purpose of the invention is to increase speed and accuracy.

FIG. I is a schematic diagram of the measurement transform; in fig. 2 - time diagrams of the converter operation when applying a periodic sinusoidal voltage to its input; in fig. 3 - the same, when applying to its input a periodic rectangular voltage with a pause at zero.

The converter (Fig. 1) contains rectifiers 1 and 2 connected to the terminals of the secondary winding of the transformer 3, the primary winding of which forms the input terminals. The middle terminal of the secondary winding forms the first output terminal 4 to which the filter capacitor 5 is connected. A free capacitor lead forms a second output terminal 6. A constant voltage source 7 is connected between terminal 4 and the first input 8 of the resistor adder 9, the second input 10 connected to the output of the gate 2, the output of the adder 9 is connected to the control input of the electronic key 11, with the first power output connected via the discharge resistor 12 to the output 6 and the second PPE output connected to the output 4,

In order to make it possible to transform a periodic rectangular voltage that has a pause at zero or the front of the rise or fall of a pulse, and suppress the pulse interference between the output of the rectifier 1 and the output 6, the resistor 13 is turned on.

The operation of the voltage converter can be examined using timing diagrams (Fig. 2).

. When the converter is turned on for trans4), the ormator 3 is supplied, for example, a sinusoidal voltage (curve. 4 in the diagram), the transformer 3 converts this voltage into two equal voltages, opposite (curves 15 and 16), which are fed to full-wave voltages

The drives 1 and 2. At the moment of switching on to the voltage from the output of the rectifier 1, the smoothing capacitor 5 starts to charge, and from tg to t (diagram 2) charges it to the amplitude value of the voltage U. From the output of the rectifier 2 the pulsating voltage is fed to the input 10 of the resistor cy f atopa 9, to the input 8 of which voltage is applied from a constant voltage source 7 (diagram b). As a result, a voltage appears at the output of the resistor adder 9 (diagram b), which controls the operation of the electronic key 11. At the time tj, when the voltage at the control input of the electronic key 1 becomes positive, it opens. . In this case, the discharge resistor 12 - open electronic switch 11 starts the discharge of the smoothing capacitor 5c of the time constant tpQjhfRC.

0

five

0

five

The discharge continues until time tg, when the voltage at the control input of the electronic key 11 becomes negative and the latter closes (diagram 3). During the time, the smoothing capacitor 5 has time to discharge by the amount (figure 2) - After the electronic key 11 is closed for a time, the voltage on the smoothing capacitor 5 remains equal to the voltage U-dU. At the time tj, the voltage at the output of the rectifier 1 becomes equal to the voltage U - uU, and the smoothing capacitor 15 is recharged to the amplitude

0 values of voltage U for time til- (diagram g). The process then repeats, and the discharge time of the smoothing capacitor 5 depends on the magnitude of the input voltage.

five .

The considered voltage converter circuit does not allow to use it for converting direct coal periodic pulsed

0 voltage with pause at zero. Introduction to the voltage converter resistor 13 eliminates this disadvantage and, in addition, contributes to the suppression of impulse noise. AT

In this case, the operation of the voltage converter can be viewed using the time diagrams shown in FIG. 3

3

When the voltage converter is turned on at the moment of time t in, the transformer 3 is supplied with a pulsed rectangular periodic voltage with a pause at zero (curve 17. On diagram H), which is converted into two voltage that are the same but opposite in phase (curves 18 and 19 on the diagram ft), and enters the full-wave rectifiers 1 and 2. At the time t o the voltage, from the output of the miter 1 begins to charge the smoothing capacitor 5 with a constant time Tzar R .e to the amplitude value of the voltage and for time to-t (diagram l) ode rectifier 2 rectified pulsed voltage supplied to the input resistor 10 of the adder 9, the input 8 is supplied with voltage source 7, a DC voltage (diagram b). As a result, a voltage appears on the output of the resistor adder 9 (diagram &) that controls the operation of the electronic switch 11. At time b) the voltage at the control input of the electronic switch 11 becomes positive and it opens (diagram 3) . When this happens, the smoothing capacitor 5 begins to discharge through it at a constant time. Lpaip R-C (diagram d). The discharge continues until time t, when the voltage at the control input of the electronic key 11 becomes negative and the latter closes. The smoothing capacitor 5 is discharged over time t by the value of whether. Then the process is repeated again, and the amplitude of the output signal depends on the magnitude of the input voltage.

It is advisable to record information about the amplitude of the input signal every half-period before the beginning of the discharge of the smoothing capacitor 5 (for example, in diagram 2, the time t - tz.).

43073

Impulse noise present in the input signal, having a short duration and a large amplitude, can affect the amplitude value of the output-5 signal, this scheme integrates such interference and their effect on the amplitude value of the output voltage is greatly attenuated. ten

The formula of the invention

h

1. Measuring converter of alternating voltage to constant, 15 containing a phase splitter in the form of a transformer, the primary winding of which forms input terminals, and the secondary one is made with an average output, forming the first output terminal to which a filter capacitor is connected to one output the other output of which forms the second output output, as well as four power diodes, which differ by 25 in order to

. speed and accuracy, additionally a DC voltage source, a resistor adder and an electronic switch, the control input of which is connected to the output of the adder, are added, the first power output is connected through the input resistor to the second output output, and the second power output - to the first output output - 2 water and one output of the source of voltage, the other output of which is connected to the first input - a resistor adder, the second input connected to the combined 40 anodes of the first rectifier, the cathode which are connected to the corresponding terminals of the transformer and to the anodes of the second rectifier diode of the secondary winding and the combined cathodes 45 are connected to the second .vyvodu. 2. The converter according to claim 1, stating that a resistor is connected between the combined cathodes of the second rectifier and the second output terminal.

OJtef./

fig.Z

Editor H, Yatsola

Compiled by E, Melnikova

Tehred D.Oleinik. Proofreader A. Obruchar

Order 3714/54 Draw 63 Subscription

VNIIGGI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5

Production and printing company, Uzhgorod, st. Project, 4

Claims (2)

Forum изобретения invention ί 1. A measuring transducer of alternating voltage to DC, 15 containing a phase splitter in the form of a transformer, the primary winding of which forms the input terminals, and the secondary is made with the middle terminal forming the first output terminal 20, to which a filter capacitor is connected with one terminal, the other terminal of which forms the second output The final conclusion, as well as four rectifier diodes, distinguishing 25 with the fact that, in order to increase. speed and accuracy, an additional DC voltage source, a resistor adder and an electronic key are introduced, the control input of which is connected to the adder output, the first power output is connected through the introduced discharge resistor to the second output output, and the second power output is connected to the first output output and one output source constant voltage *, the other output of which is connected to the first input of the resistor adder, the second input connected to the combined 40 anodes of the first rectifier, the cathodes of which are connected to the corresponding terminals of the secondary winding of the transformer and to the anodes of the diodes of the second rectifier, the combined cathodes of which are connected to the second output. 2. The converter according to π. 1, characterized in that a resistor is connected between the combined cathodes of the second rectifier and the second output terminal. fig.Z _l Compiled by E. Melnikov