SU836596A1 - Digital extremum ac brige with decade-wise following balancing - Google Patents

Description

balancing steps; which must be carried out to balance the measuring circuit. With low sensitivity, even with a significant imbalance of the measuring circuit, the amplitude of the error signal may be lower than the response level (threshold element, and the balancing is performed in minimal discrete steps. As a result, the balancing time will be large.

The purpose of the present invention is to increase the speed of the bridge with a variable sensitivity of the bridge circuit.

The goal is achieved by the fact that a digital extreme AC bridge with a decadal tracking followed by a generator of operating frequency, connected to a bridge measuring circuit and connected in series by a modulator, and the decade divider output a bridge measuring circuit connected in series to a selective amplifier a detector, a normally closed switch and an OR element with a control unit whose output is connected to the inputs of a pulse distributor selective ilitel and decade divider, one terminal of a normally closed switch connected to. the input of the trigger trigger, the output of which is connected to the inputs of the reversible counter and modulator, the second OUTPUT of the extremum detector through a second normally closed switch connected to the second input of the pulse distributor, the output of which is connected to the second input of the reversible counter, the output of which is connected to the bridge measuring circuit, the output of the selective amplifier is also connected to the input of the threshold element, a pulse generator, the output of which is connected to the second input of the element OR via a normally open key, Consequently, the connected switching element, the reversible pulse counter, the block for filling the counter with the second element OR, the output of the threshold element are connected to the second input of the second OR element, the output of which is connected to the control inputs of two normally closed switches and the control unit, the second output of the extremum detector is connected to the input switching element, the second output of which is connected to the third input of the first element OR, the first output of the extremum detector is connected to the second input of the reversing account pulse pulse, the output of the block for filling the counter is connected to the control input of the auxiliary divide, l, connected between the decade divider and the bridge measuring

circuit and the second input of the switching element.

If the bridge is balanced by a parameter in which the sensitivity of the measuring circuit is variable, then the pulses from the output of the imbalance signal of the extremum detector come both to the input of the pulse distributor and to the input of the pulse counter with a circuit for fixing its filling. When the counter is filled, which indicates a possible large imbalance of the measuring circuit, the output signal of the counter-filling fixation circuit outputs the extremum detector are disconnected from the inputs of the distributor, the reverse trigger and the control unit, the latter being set in the reverse direction. At the same time, the modulation effect is increased by changing the state of the auxiliary modulation divider, and the input of the imbalance signal of the extremum detector is connected by means of a switching circuit to the input of the OR circuit at the input of the control unit.

In the next cycle, an increased modulation effect is performed. If an imbalance signal appears at the output of the extremum detector (evidence of a significant imbalance), then it passes to the input of the control unit. As a result, the automation system is set to a state corresponding to the equilibration of the measuring circuit at a higher discharge. In the next cycle, an increased modulation effect is again performed in the same direction.

In each of the subsequent cycles, the state of the control unit will change until an equilibrium signal pulse appears at the output of the extremum detector. This first impulse (evidence that there is no large imbalance at this discharge) resets the impulse counter with the fixing circuit of its filling. In the O state. As a result, the control unit is set in the direct counting direction, the magnitude of the modulator / distributor inputs decreases The reverse trigger and the control unit are connected to the outputs of the extremum detector, which, by the reaction of the measuring circuit to modulation effects, generates control signals.

Claims (2)

1. Melik-Shakhnazarov OM and others. Autocompensation devices of extreme type. Energy, 1969, with. 50. 2. Grinevich FB Automatic bridges of variable TOKai SB RAS USSR, 1964, p. 172 (prototype).