SHZ-DFE type constant speed source

SHZ-FType constant speed source (hereinafter referred to asSHZ-F）It's based onJJG622－1997Verification Regulations for Insulation Resistance MetersJJG366－2004The specialized product designed and produced in accordance with the technical requirements of the "Verification Regulations for Grounding Resistance Meters" is the original product of our factorySHZ-DThe improved version of the constant speed source adopts a LCD display screen, with a beautiful appearance, simple operation, and outstanding noise reduction effect, which can meet the calibration needs of all models of mechanical megohmmeters and grounding resistance meters.

Main technical parameters

Speed range:100 ～ 250Conversion/Minute

Constant speed point:120Conversion/minute,150Conversion/Minute

Accuracy:±1turn

Voltage used:220V±22V，50Hz±5 Hz

power waste:100W

Weight:10kg

External dimensions（mm）：385 ×305 ×355

The SHZ-F constant speed meter (hereinafter referred to as SHZ-F) is a specialized product designed and produced in accordance with the technical requirements of JJG622-1997 "Verification Regulations for Insulation Resistance Meters" and JJG366-2004 "Verification Regulations for Grounding Resistance Meters". It has a more intuitive display mode, more prominent noise reduction effect, lighter weight, and can meet the verification needs of various positive and off axis hand cranked megohmmeters and grounding resistance meters. This instrument combines the characteristics of various constant speed sources in China and user feedback. It is driven by a stepper motor with two starting speeds of 120 and 150 rpm. The maximum designed speed is 250 rpm, which can be set arbitrarily through a speed control switch and does not fluctuate with load changes. The touch switch and coaxial balancing device integrate the control system with the work, making it easy to operate and reliable in performance.

Principle Introduction

The microcontroller and crystal oscillator are used to generate PWM signals that match the motor speed. The start button and speed control button are combined into a multifunctional key to jointly complete the functions of starting speed and step speed control. The PWM signal generated by the microcontroller is amplified by the driving circuit and directly drives the stepper motor, which in turn drives the motor. The speed of a stepper motor is determined solely by the frequency of the PWM and is independent of the supply voltage, therefore, its speed does not change with changes in the load.

4.1 Functional modules

The device includes: (1) speed display, (2) speed adjustment and start control, (3) power socket and switch, (4) locking knob of the tested meter, (5) coaxial balanced speed drive plate, (6) PTFE pressure pad, (7) tilt adjustment, and other functional modules.

4.2 Check that the appearance of the instrument is intact and that all knobs move smoothly.

4.3 The instrument is installed on a horizontal table with the power switch turned off and the power cord connected.

4.4 Place the tested meter on the workbench, move the tested meter to align the center of the handle with the center of (5), adjust the height with (6) to align the center of the tested meter with the center of (5), and achieve coaxiality. Then insert the tested meter handle into (5) and lock it with (4).

4.5 Turn on the power switch, press the corresponding start button, and the motor will start at 120 rpm or 150 rpm. Press the speed adjustment acceleration button and deceleration button respectively, and adjust them freely within 100-250 rpm. The tested meter will start working.

When the calibration is completed, press the "start stop" button to stop the motor and turn off the power.

4.7 Adjusting (7) separately allows the instrument to perform tilt tests at 5 ° in the front, back, left, and right directions.

5 Precautions: If the motor loses step during use, press the "start stop" button in a timely manner, readjust the fixed position of the megohmmeter, and then restart it to work normally. When verifying special specifications of megohmmeters and grounding resistance meters, the tested meter should be in an open circuit state before starting the instrument.