SU674047A1 - Function generator - Google Patents

Description

I

This invention relates to analogue technology.

A functional converter is known that reproduces a piecewise linear approximating polygonal line. It contains transistor cells, the emitter of the output transistor of each of which is connected to the output of converter 11.

A disadvantage of the known converter is the low accuracy of the reproduction of functions.

Also known is a functional converter containing slope setting potentiometers connected between the converter input and a zero potential bus, transistor cells, the collector of the output transistor of each of which is connected to the negative terminal of the supply voltage source, the base of the first transistor of each transistor cell is connected to the middle output of the corresponding reference potentiometer slope, the collector is connected to the negative terminal of the voltage supply to which the collector th resistor connected vyurogo collector of the transistor and the output transistor base 2 ..

Each limiting potentiometer is connected to the terminals of the reference voltage source, and its middle output is connected to the output of the converter via a corresponding resistor voltage divider, the middle output of which is connected to the base of the second transistor, the emitters of both transistors of each transistor cell are connected to the positive terminal via a third emitter resistor source of nuru feeding.

A disadvantage of the known converter is the low accuracy of the reproduction of functions due to the instability of the output voltage when switching transistor cells.

The aim of the invention is to improve the accuracy of the converter.

To achieve this goal, the functional transducer contains switching diodes and load resistors, each of which is connected between the emitter of the output transistor of the corresponding transistor

cells and a zero potential bus, each switching tone is connected between the emitter of the specified transistor and the output of the converter.

Fig. 1 shows a functional converter, an electrical circuit diagram, Fig 2, an output characteristic of the converter.

The functional converter contains n transistor cells li-In according to the number of pin-sized sections of the approximating function.

Each transistor cell 1 contains potentiometers for setting a slope 2i-2n, output transistors 3i-Зп, a voltage divider of series-connected resistors

4) -4p and 5, -5p, limiting potentiometers 6i-6p, transistors 7i-7p and 8j-8p, the emitters of the second are connected to the corresponding emitter resistors 9) -9p, the collector resistors 10) -Gop connected between the collectors of transistors 8) - 8ri and negative bus 11 - source of supply voltage. The positive bus 12 of the supply voltage through the emitter resistors 9i-9n is connected to the emitters of the transistors 7, 8. The limiting potentiometers are connected to the terminals 13, 14 of the reference voltage source.

The input of the converter is denoted by 15. The output transistor 3 emitter of each cell is connected to the ground potential through the corresponding voltage resistor 16i-16n and through the switching diode 17, -17p and the output of the converter. The function converter works as follows

Each transistor cell 1 is assembled in accordance with a constant-negative-voltage-feedback amplifier circuit. The input cascades of amplifiers are assembled on transistors 7b 8i-7M, 8p, included tic difference circuit cascade.

The output stages are assembled on the output transistors 3i - 3f, included in the emitter follower circuit. The negative feedback is closed through the resistors of the divider 4, 5 {- 4п, 5пи the corresponding switching diode I / i-17п.

A given piecewise linear function can be formed — from a set of linear segments, with appropriately selected initial displacements UQI, UQJ, Uoa — and the steepness KI, K7, .. by choosing the one of them, whose value is currently maximal. In FIG. 2, the maximum values of the linear functions are highlighted with help.

Linear functions are formed by the li-In transistor cells. The slope of the corresponding function is set by the slope setting potentiometers. 2i-2n, and the initial MOTION with limiting potentiometers 6, -6p. Selecting the maximum modulo value at the output of the converter from the set of output voltages of the transistor cells Ij - In, perform the switching diodes 17i-17. At a certain input signal of the converter, at the output of each transistor cell li-In, it is set better, corresponding to the gain factor and the initial offset of the given cell. However, since all the output transistors 3i-3n are connected through the switching diodes 17i -17h to the output of the converter, the maximum voltage is generated on it. In this case, the switching diode 17 of the corresponding transistor cell 1 is open, and all other diodes are locked. The feedback for this transistor cell 1 is closed through diode 17 and the corresponding emitter resistors 4 and 5. For the other transistor cells, the feedback is open and the zmitter current of transistors 3i-3n is closed through load resistors 16i -16f, c

The use of the invention will make it possible to increase the stability of the output signal of the functional converter, which makes it possible to apply it in a more rapid range of ambient temperatures and, in this case, refuse to develop and manufacture thermostatic devices.

Claims (1)

Invention Formula A functional transducer containing potentiometers for setting the slope, connected between the input of the converter and the nude potential, transistor cells, the collector of the output transistor of each of which is connected to the negative terminal of the supply voltage, the base of the first transistor of each transistor cell is connected to the medium terminal of the corresponding potentiometer for setting the slope of the transistor the collector is connected to the negative terminal of the power supply to which through the collector a resistor The collector of the second transistor and the output transistor base are connected, each Limit potentiometer is connected to the terminals of the reference voltage source, and its middle output is connected to the output of the converter through a corresponding resistor voltage divider, the middle output of which is connected to the second transistor, each emitter of each transistor cells through a third emitter resistor are connected to the positive terminal of the power supply, characterized in that; that, in order to improve accuracy, it contains a 1a switch