Measurer tachometer digital Shch1480
Also, this device can be called: Shch-1480, Shch 1480.
Measurer tachometer digital Shch1480 is designed to measure the frequency generated tachometer, indication of the measurement result on the digital indicating device and outputting measurement results in the form of coded electrical signal to the centralized control of the car. The structure includes meter converter Shch1480/P and reading device Shch1480/I.
Principle of operation Shch1480 is counting up the number of periods of the measured frequency interval for the model. Of a sinusoidal voltage from the tacho or other primary tach converter formed rectangular pulses that make up periods of the measured frequency. Exemplary time interval form crystal oscillator and frequency divider. The magnitude of the interval depends on the model range.
The operation of the digital meter is carried out by the control circuit.
Pulse counter counts the number of periods of the measured frequency interval for the model and contains four counting decade working as code 8-4-2-1. In the next cycle, the measurement information received from the counter pulse signal from the REC control circuit keeps the storage register.
Decoder converts BCD 8-4-2-1 in decimal, then fed on high keys that control the digital indicator lamps indicating device SCH1480 / I.
Output circuit for the MSC converts the signals output from the memory into signals of negative polarity amplitude 8B ± 10%.
Measurer tachometer digital Shch1480 the speed of the shaft of a gas turbine power plant with tachogenerator or other primary device.
After the start of the rotation shaft indicating device appears count corresponding to the rotational speed of the shaft.
Specifications measurer tachometer digital Shch1480
- 127V with 50Hz;
- 220V frequency 400Hz.
Insulation resistance of electrical circuits relative to the body at a temperature of 25 ± 10 ° C and relative humidity up to 80% - 20MOm.
Power consumption meter Shch1480 from network - does not exceed 60V · A.
Dielectric strength between the body and chains reading device, the housing and the supply circuits and power supply circuits and circuits outputs CIP at 25 ± 10 ° C and relative humidity up to 80% - 1.5 kV.
The outputs of the meter on the machine centralized control (ISC) serves parallel code 8-4-2-1 and at a current of 5 mAravny:
- "1" - 8V ± 10%;
- "0" - no more than 6V.
Measurement ranges, the measurement and the coefficient at the speed tachometer tacho 2500 rev / min are shown in the table.
Maximum permissible error meter 0.1% of the upper limit of the measuring range.
Maximum permissible error Shch1480 meter:
a) the change of ambient temperature δ t Percentage in the temperature range from 0 ° C to 40 ° C at a relative humidity of up to 80% less than the values determined by the sum of the maximum permissible basic error of the meter at normal temperature and product temperature difference (normal temperature and at which the determined error) by a factor of 0.005;
b) at ambient temperature of 40 ° C and 90% relative humidity does not exceed ± 0,2%.
Meter error by an external magnetic field of 400 A / m does not exceed the permissible basic error.
Operating conditions Shch1480
The apparatus is designed for operation at ambient temperature from 0 ° C to 40 ° C and a relative humidity of 98% at 40 ° C in tropical climates with temperatures from 1 ° C to 45 ° C and a relative humidity of 98% at 45 ° C.
- Shch1480/I - 120x80x102 mm;
- Shch1480/P - 480x300x180 mm.
Weight Shch1480/I - no more than 1 kg.
Weight Shch1480/P - not more than 12 kg.