DE2839732A1 - General purpose mechanical parameter measurement - involves control circuit contg. summing and power amplifiers with hysteresis generator - Google Patents

Abstract

An electronic circuit for measurement and control of mechanical parameters has an actual value transducer, demand generator and summing amplifier comparing actual and demand values. It is partic. applicable to linear position contro. It is more widely applicable than conventional circuits. The summing amplifier output drives a power amplifier whose switching point is adjusted by a hysteresis circuit connected to the summing amplifier. The actual value signal is produced by a mechanical pick-up an electronic sensor coupled to it, and a converter changing the sensor signal to a linear direct current signal.

Description

Circuit arrangement

Description The invention relates to an electronic circuit arrangement for measuring and regulating mechanical quantities, especially paths, with an actual value transmitter, a target value transmitter and a summing amplifier for comparing the actual value and Target value.

The invention is based on the object of a circuit arrangement of the aforementioned type so that they are more versatile than the known circuits can be used.

According to the invention this is achieved in that an output of the Summing amplifier placed a power amplifier for outputting a correction signal is and that a hysteresis sensor is coupled to the summing amplifier for Linstellung the switch-back point of the power amplifier.

The actual value transmitter expediently consists of a mechanical one Transducer, an electronic transducer coupled to this and a signal converter coupled to the latter for converting the measurement signal into a linear direct current signal, the signal converter being connected to an input of the Summing amplifier is placed.

A test value transmitter is preferably associated with the electronic measured value sensor coupled for the optional input of a standardized test signal, for example, for function monitoring the circuit arrangement.

For constant monitoring of the target value, the target value transmitter an AnalqDigital-llandler who in turn a digital one Controls display device and / or a printer.

It is also possible to monitor the actual value at an output of the SaTmm For amplification, an analog-to-digital converter must be installed, which has a printer and / or can control a digital display device in order to continuously display the actual value.

An example embodiment of the invention is shown below explained with reference to the single figure of the drawing, which schematically shows an inventive Circuit arrangement in the form of a block diagram shows.

The circuit arrangement 10 consists of a mechanical transducer, especially for the detection of mechanical movements. This can be e.g. pressure switches or temperature switches, or other devices that use physical quantities be converted into mechanical movements.

The mechanical transducer 12, which is in the form of a membrane or a piston can be formed is with an electronic transducer 14 connected, e.g.

can work inductively or capacitively and the mechanical signal into an electronic signal. The electronic transducer 14 is in turn connected to a signal converter 16, the incoming electrical Signal converted into a proportional, linear direct current signal.

The output of the signal converter 16 is connected to an input of a summing amplifier 18 connected, which has a further input to which a target value transmitter 24 is placed is. The actual value coming from the signal converter 16 is included in the summing amplifier 18 compared to the target value coming from the target value transmitter 24. Is the If the value is smaller than the nominal value, the summing amplifier 18 does not emit a signal from, while if the actual value corresponds to the target value or greater than this is, a signal from the output of the summing amplifier 18 to a trigger circuit 20 is placed, which in turn drives a power amplifier 22, e.g. Relay switches Instead of the relay, however, suitable half-wire switches can also be used can be used as a power output.

In general, the relay can now switch back to its starting position if the actual value falls below the target value.

In the present circuit arrangement, however, it is provided that the relay only switches back to its initial state when the actual value has fallen to a certain, predetermined value. For this purpose is with one Another input of the summing amplifier, a hysteresis sensor 26 is connected to which the hysteresis, i.e. the difference between the switch-on point and the switch-back point of the Relay or the power amplifier 22 can be set. Both the setpoint as well as the switching hysteresis can be used in the summing amplifier in the form of variable Sizes are entered.

The specified value for the target value and the actual value can be set at 44 or 42 can be tapped analogously and displayed.

An analog / digital converter 30 is also provided with the setpoint value transmitter 24 connected, through its output e.g. a digital display device 38 and / or a Printer 40 are controllable, which makes it possible to constantly digitally set the target value to display.

Furthermore, an analog / digital converter is connected to an output of the summing amplifier 18 36 connected, the output of which is a digital display device 32 and / or a printer 34 controls so that the actual value signal can also be displayed digitally at all times.

It is also possible to set the target value and the Value for the switching hysteresis in programmed form with the help of a separate, not shown programming device to enter. After programming the target value and the value for the switching hysteresis can then be suitably stored internally and both can only be done by reconnecting the programming device deleted or changed.

As the figure shows, according to a further embodiment of the invention Circuit arrangement, a test value transmitter 28 is provided, which is connected to the electronic Transducer 14 is connected. The test value generator 28 allows when switched off mechanical transducer 12 a standardized test signal, for example, to the electronic To put transducer 14, which is processed like a mechanical transducer 12 received signal and can be used, for example, the proper Check function of the circuit arrangement.

L e r s e i t e

Claims (5)

Claims 1. Electronic circuit arrangement for measuring and Control of mechanical variables, with an actual value transmitter, a target value transmitter and a Summing amplifier for comparing actual value and target value, g e k e n n z e i c h -n e t controllable by one through the output of the summing amplifier (18) Power amplifier (22) and through one coupled to the summing amplifier (18) Hysteresis transmitter (26) for setting the switch-back point of the power amplifier. 2. Circuit arrangement according to claim 1, characterized in that g e -k e n n z e i c h n e t that the actual value transmitter consists of a mechanical transducer (12), one with this coupled electronic transducer (14) and one with the latter coupled signal converter (16) for converting the measurement signal into a linear direct current signal exists, which in turn is connected to an input of the summing amplifier (18) is laid. 3. Circuit arrangement according to claim 1, g e k e n n -z e i c h n e t by a test value transmitter connected to the electronic transducer (14) (28) for the optional input of a standardized test signal, for example, for function monitoring the circuit arrangement. 4. Circuit arrangement according to one of the preceding claims, characterized g e k e n n g e. i c h n e t that the setpoint value is sent to the setpoint value transmitter (24) connected analog / digital converter (30) is constantly digitally tapped. 5. Circuit arrangement according to one of the preceding claims, characterized it is noted that the actual value is sent to the summing amplifier via a (18) connected analog / digital converter (36) is constantly digitally tapped.