SU426134A1 - DIGITAL TENSOR METER - Google Patents

Description

I

The invention relates to the field of electrical measurements of non-electrical quantities and can be used in devices for measuring strain using strain gages.

Known digital strain gauge - a device containing an electric bridge with a strain gauge in one of the arms, a null body included in the output diagonal of the bridge, digital controlled conductivity, shunting one of the bridge arms, a register connected to the digital controlled conductivity, a decoder that connects alternately register bits, and a clock generator connected to the decoder.

The proposed device differs from the known one in that it is equipped with two electric circuits, each of which contains a series-connected resistor and a key and is connected in parallel to one of the adjacent shoulders of the bridge, two coincidence circuits, one input of each of which is connected to the zero-organ output, two the triggers, the inputs of which are connected to the outputs of the coincidence circuits, and the third coincidence circuit, the inputs of which are connected to the opposite outputs of the triggers, and the decoder is equipped with additional outputs connected to the keys and the secondary bubbled inputs of coincidence circuits.

In such a design, the device allows for automatic control of the reliability of measurement results.

The drawing shows a block diagram of the proposed device.

The device contains an electric bridge, made on resistors 1, 2, 3 and one strain gauge 4, a zero-body 5 included in the measuring diagonal of the bridge, power supply 6, digital controlled conductivity 7 formed by resistors 8 and keys 9 and shunting one of the arms bridge, register 10 with triggers 11, decoder 12, the d-inputs of which connect alternately register bits 10, two electrical circuits consisting of series-connected resistors 13, 14 and keys 15, 16 and connected in parallel to two adjacent arms of the bridge, two circuits 17, 18 joint resolution Denia, one input of each of which is connected to the output of the zero-organ 5, two flip-flops 19, 20, the inputs of which are connected to the outputs of the matching circuits 17, 18, and the matching circuit 21, the inputs of which are connected to opposite outputs of the flip-flops 19, 20, generator 22 clock pulses and the counter 23, and the inputs of the keys 15, 16 and the second inputs of the circuits 17, 18 coincidence are connected with additional outputs n- | -1 and / g + 2 decoder 12.

When the generator 22 is operating, the clock pulses, the passage through the counter 23, are applied to

decoder 12. At the outputs of the decoder, pulses will appear. When a control pulse is fired at the first output of the decoder 12, the trigger 11 of the higher bit of register 10 is set to state I, and the switch 9 of this bit is closed by connecting the high bit resistor 8 in parallel with the resistor 2 of the bridge. Further, depending on the signal at the output of the null organ 5, the trigger 11 of the most significant bit either stays in the state I or is reset to 0. Similarly, the bridge is balanced by other bits. After the end of the nth clock cycle, the balancing process is terminated, and the measurement result is recorded in the triggers 11 of the register 10.

In the next cycle, the signal from the output of the decoder 12 is supplied to the coincidence circuit 18 and to the control input of the switch 16, which closes, connects the resistor 14 parallel to the resistor 2 of the bridge. If the bridge is close to the equilibrium state, then a signal appears at the output of the null organ 5, which through the circuit 18 sets the trigger 20 to the state I.

In the next step, the signal from the output L + 2 of the decoder 12 is fed to the input of the matching circuit 17 and the switch 15, which connects the resistor 13 parallel to the resistor 1.

If at the end of a process, the bridge is close to the equilibrium state, then in the l + 2 clock cycle the sign of the bridge unbalance differs from the bridge unbalance sign in the n- | -1 clock cycle, and the signal from the zero-organ 5 is absent, and trigger 19 remains in the state 0. Thus, with a good strain gauge and no interference trigger 20

after the end of n - {- 2 clocks is in the state I, and the trigger 19 - in the state 0. At the same time, at the output of the coincidence circuit 21 there will be a signal indicating the correctness of the result. The absence of a signal at the output of circuit 21 indicates a failure of the strain gauge.

Subject invention

Digital strain gauge device containing an electric bridge with a strain gauge in one of the arms, a null organ included in the output diagonal of the bridge, digital controlled conductivity shunting one of the bridge arms, a register connected to the digital controlled conductivity, a decoder connecting alternately bits the register

and a clock pulse generator connected to a decoder, characterized in that, in order to provide automatic control of the accuracy of measurement results, it is equipped with two electrical circuits, each of which contains a series-connected resistor and key and is connected in parallel to one of the adjacent shoulders of the bridge, two circuits matches, one input of each of which is connected to the output of the null organ,

two triggers, the inputs of which are connected to the outputs of the coincidence circuits, and a third coincidence circuit, the inputs of which are connected to the opposite outputs of the triggers, and the decryptor is equipped with additional outputs connected to the keys and the second inputs of the coincidence circuits.

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