SU757980A1 - Stroboscopic tachometer - Google Patents

Description

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one

This invention relates to a measuring technique and can be used to build devices for contactless measurement of the frequency of rotation and oscillation of moving parts of machines and devices.

Known stroboscope containing an auto-oscillator, a pulse shaper-amplifier, a flash lamp with a starting circuit, a frequency meter and a power supply [13.

The disadvantage of the device is the low frequency of the device.

Also known is a strobometer, containing a power source, a master oscillator, a frequency divider, a power amplifier and an ignition circuit of a flash lamp, the power circuit of which contains a choke and a PCM-3 relay.

A disadvantage of this device is the small speed measurement limit due to the low maximum strobe light frequency.

The aim of the invention is to expand the measurement range by increasing the frequency of flashes, flash lamp.

2

This goal is achieved by introducing an additional resistance into the anode circuit of a pulse lamp, two current keys, a high-voltage transformer and a damper diode, and the first output of the control unit is connected to the first current key, the output of which is connected to the control through a high-voltage transformer and high-voltage capacitor. the pulse lamp electrode, the damper diode is connected in parallel to the primary winding of the transformer, and the common resistance point of the anode circuit of the pulse lamp is connected to the collector ru of the second current key, the control input of which is connected to the second output of the control unit.

FIG. 1 shows the scheme of the proposed tachometer, which consists of a master oscillator 1, a divider 2, a digital frequency meter 3, a control unit 25 4, a start-up oscillator 5: em 5, a resistance 6, a pulse lamp 7, a capacitor 8, a high-voltage pulse transformer 9 10, resistances 11 and 12, switch range3

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Zones 13, current switches 14 and 15, flash lamp 16 and four capacitors 17.

The control circuit consisting of the control unit 4 and the starting circuit 5, after each pulse from the output of the divider 2, produces one flash of the pulse lamp 16, i.e., the frequency of the flashes of the lamp 16 is equal to the clock pulses at the output of the divider 2.

Since the measurement of the speed of an object is easy to count in minutes and to increase accuracy, it is advisable to use a digital frequency meter with a measurement time of 1s, · the divider 2 with a division factor of 60 is included in the circuit, i.e. the digital frequency meter reads 3 all the time is 60 times less than the flash frequency of the flash lamp 16, which provides readings of the number of revolutions of the object being measured on the digital frequency meter. in minutes.

The control unit ¹ performs the functions of a frequency converter. After the trailing edge of each pulse applied to the input of block 4 from the output of divider 2, a single pulse is output to the output of <G; it lasts for a period dt mp (1d mt n-time deionization of the lamp at zero current), and at the output a. the leading edge of the pulse at the output of sG, after a time ι _κ sufficient to turn on the high-voltage current switch 14, one short-term pulse is issued. So the frequency of the pulses at both outputs of the control unit 4 is always equal to the frequency of the pulses at the input (see Fig. 2, 3, 4). Until a pulse arrives at the input of the control unit 4, one of the capacitors 17 is charged to the anode voltage I _g , through the anode resistances 11, 12 and the switch 13.

After the back, the front of the pulse applied to the input of the control unit 4, at its output K, one pulse is issued, with a duration of 1 dpm, which is fed to the control input of the high-voltage current switch 14, due to which the union points of the anode resistances 11, 12 are closed to ground. After the leading edge of the pulse from the output b, after a time импульс дается _κ, an intermittent pulse is output to the output of a, which is fed to the high-frequency control input. current key 15. Prior to the receipt of this pulse, the capacitor 8 through the resistance 6 was charged to voltage and.

Short-term opening of the current key 15 creates a short-term pulsed current in the primary winding of the high-voltage transformer 9, which, in turn, creates in the secondary winding a high-voltage short-term voltage pulse, which later

through the separation capacitor 10 enters the grid of the flash lamp 16, which causes its ignition, i.e. the charged capacitor 17 through the switch 13 is discharged on the lamp 16.

After applying the next pulse to the input of the control unit 4, one pulse will again be issued from both outputs a and cG of block 4, which will also be followed by the next flash of the flash lamp 16, etc.

A damping diode cuts a negative surge voltage at the output of the transformer 9. The current switch 14 is turned on at a time ΐ _to the ignition pulse, due to the fact that it was open after the flash, which caused the current through the lamp to stop and no arc appears. and the cathode. After opening the current key 14 for a time from _{k to the} charged capacitor 17 will begin to discharge through the resistance 12 and through the key 14.

To eliminate electrical interference pulse transformer 9 is placed in the handle of the illuminator, made of non-ferrous metal.

The function of the switch 13 is as follows. With this switch, one of the capacitors 17 is switched on in the anode of the lamp.

The entire measurement range is divided into several subranges. For each range, based on the maximum frequency of this range, the capacitance is calculated.

Claims (1)

Claim A stroboscopic tachometer containing a series-connected master oscillator, a frequency divider, a control unit, a flash lamp, and a frequency meter connected to the generator output, characterized in that, in order to extend the measuring range, an additional resistance is introduced into the anode circuit of the pulse lamp, two current switches, high-voltage transformer, high-voltage capacitor and damper diode, while the first output of the control unit is connected to the first current switch, the output of which is through the high-voltage transform Ator and high-voltage capacitor is connected to the control electrode of the pulse lamp, damping diode is connected in parallel to the primary winding of the transformer, and the common resistance point of the anode circuit of the pulse lamp is connected to the collector of the second current switch, the control input of which is connected to the second output of the control unit .. five 757980 6