SU984008A1 - Controllawle sawtooth voltage generator - Google Patents

Description

a radio amplifier and a charging resistor, an electronic switch connected in parallel to the capacitor, and a control input of the electronic switch connected to the clock source bus, an adder and an analog multiplier, the first input of which is connected to the voltage source, the second input is connected to the first input of the adder and with the control voltage source bus, and the output, is connected to the non-inverting input of the first operational amplifier and to the second input of the adder, the output of which is connected to the second output terminal about a reistor.

FIG. 1 shows a circuit diagram of the device; in fig. 2 and 3 are diagrams showing the work of the scheme.

The device contains the first operational amplifier 1, the first resistor 2, the second resistor 3, the second operational amplifier 4, the third and fourth resistors 5 and b, the capacitor 7, the electronic switch 8, the adder 9, the analog multiplier 10, the centering bus 11 voltage, bus 12 of the source of sync pulses, bus 13 of the source of control voltage, bus 14 of the source of bias voltage.

The device works as follows. in a way.

The electronic key 8. is controlled by sync needle pulses (Fig. 2a, Fig. Pro). In the time interval t. . . . t2. The electronic key is closed and the circuit from the sources of control voltage and bias voltage to the output of the second operational amplifier is a non-inverting amplifier with a transmission coefficient equal to the transmission coefficient of the analog multiplier 10, i.e. voltage on. The output of the operational amplifier 4 will be ravyo (Fig. 26): vnp / where K is the transmission coefficient of the analog multiplier; and - the initial value is not offset; i) pr is the magnitude of the control voltage. This direction will not depend on the centering of the pattern of U ", due to the large loop gain. At time t, the electronic key 8 is opened, and then the circuit operates as an integrator until time tj. For the time interval t ... t, the output voltage of the second operational amplifier iiU. is defined by the expression

 and -) Price list

 ft.c

Chr 1smoChi pr / RC) t

U)

where R is the resistance of the charging resistor 2;

C - capacitor capacitance 7; t is the current time

tjsS t t ,,. When performing equality

.

CNc

where t t., - t

voltage U at time t will be equal to 4 (icMo will be equal at time t (Fig. 26):

When the magnitude and sign of the control voltage is changed, the amplitude, slope and its sign of the sawtooth voltage Uj will change proportionally, and the level of the sawtooth voltage at time to remain constant and equal to zero (Fig. 3b).

When the value of the slip voltage at the input of the UCM analog multiplier is changed, the voltage at the output of the second operational amplifier during the operation of the clock pulse (time interval t ... t) will also be determined by expression (1), and in the time interval t ... t - expression (2).

The steepness S of the sawtooth voltage remains constant at that, independent of the bias voltage (Fig. 26, Fig. 2c): S H pt dt RC When the control voltage changes, the slip height, the slope and its sign will change proportionally of the sawtooth voltage Ud, the level of the sawtooth voltage remaining, constant and equal to zero at the time T of the time t displaced relative to the time tg (Fig. 2c, Sv) and defined by the expression ..

The voltage Uy at the output of the first operational amplifier 1 will be a linear function of the voltage and J and the centering voltage Vui

and AU, + BUu ,. 1 4 where A, B are constant proportionality coefficients, depending on the values of resistors 5 and b. The level of constancy of the sawtooth tension at the moment of time to when the control voltage is changed is proportional to the centering voltage U (Fig. 2d, Fig. 3g

At time t, the electronic switch 8 is closed, the circuit returns to the initial state, the process is repeated.

Claims (2)

Invention Formula A controlled sawtooth generator, containing a first operational amplifier, the inverting input of which is connected to the first terminal of the first resistor, the output through the second resistor is connected to the non-inverting input of the second operational amplifier, inverted the input of which is connected via a third resistor with a fault of a source of a centering voltage, and through a fourth resistor to its output, which is connected via a capacitor to the inverting input of the first operational amplifier, an electronic switch connected in parallel to the capacitor, and a control input of the electronic switch connected to the source bus sync pulses, which is also distinguished by the fact that, in order to expand its functionality, an analog multiplier is introduced into it, the first input of which is 5 connected to the source bus eg Displacement, the second input is connected to the first input of the adder and the control voltage source bus, the output is connected to non-inverting n the input of the first operational amplifier and the second input of the adder, the output of which is connected to the second output of the first resistor. Sources of information taken into account in the examination 1. USSR author's certificate 422085, cl. H 03 K 4/48, 10.06.74. 2. USSR author's certificate No. 684727, cl. H 03 K 4/50, 05.23.77. toi to tl t2 t3 Us ,