SU410273A1 - - Google Patents

Description

one

This invention relates to a measurement technique.

A measuring device for a balancing machine is known, which contains an imbalance sensor connected in series and a selective amplifier with frequency-dependent feedback loops.

In order to improve the measurement accuracy in case of rotational speed of a balanced rotor, the proposed device is equipped with a phase discriminator connected to the amplifier input and output and a field-effect transistor controlled from it, connected to a frequency-dependent circuit.

The drawing shows a block diagram of the proposed device.

The measuring device to the balancing machine contains successively connected imbalances 1 and 2, a circuit 3 eliminating the influence of the balancing planes and a selective amplifier 4 consisting of an operational amplifier 5, a frequency dependent circuit 6-9, a phase discriminator 10 with phase-shifting stage 11 connected to the input and the output of the amplifier 4, the field-effect transistor 12, included in the frequency-dependent circuit, an imbalance value pointer 13, a pulse shaper 14 and a flash lamp 15. The device operates with eduyuschim way.

When the balancing rotor is rotated, the voltage from sensors 1 and 2 goes through circuit 3 to the input of selective amplifier 4, to the output of which the imbalance signal is measured by pointer 13. Then, through pulse shaper 14, voltage is supplied to pulsed lamp 15 illuminating the scale on the rotor.

The resonant frequency of amplifier 4 can be changed by changing the capacitance and resistance of the frequency-dependent circuit and the resistance between the electrodes of the field-effect transistor 12, which depends on the voltage at the gate of the latter, supplied from the phase discriminator 10 connected to the negative feedback circuit of the operational amplifier.

If the amplifier is tuned to the resonance of the signal frequency, then the phase shift between the voltages Ui and Uz is 180 °, and the control

the signal from the phase discriminator 10 is zero. When the rotor speed changes, the signal frequency deviates from the resonant frequency of the amplifier, the phase shift between voltages Ui and 1/2 becomes less than 180 °

or more. Accordingly, at the gate of the field-effect transistor 12, a voltage of positive or negative polarity arises from the output of the phase discriminator.

This voltage changes the resistance value of the field-effect transistor 12 and the tuning frequency of the amplifier 4.

The change in the resonant frequency occurs until the phase shift between the voltages Ui and t / 2 becomes 180 °, which corresponds to the setting of the selective amplifier at the frequency of the measured signal.

Subject invention

Measuring device to a balancing machine containing sequentially

An imbalance sensor and a selective amplifier with a frequency-dependent lack of feedback are included, characterized in that, in order to improve the measurement accuracy when the rotational speed of the balancing rotor is not constant, it is equipped with a phase difference device connected to the input and output of the amplifier and controlled from it by a field-effect transistor in the frequency dependent circuit.