IV-21 vacuum luminescent digital indicator multi-digit purpose, which displays information in the form of auxiliary information on the service level in the means of displaying information for group and individual use, and numbers from 0 to 9 and a decimal point in each of the 8 digital digits. IV-21 indicators are widely used in various electrical, radio and instrumentation.
The IV-21 indicator case is glass, cylindrical, the outputs are all flexible. Weight indicator IV-21 no more than 13 grams.
Purpose of the outputs of the IV-21 indicator:
1 - cathode;
2 - r1..g9 - anode-segments from the 1st to the 9th category;
3 - v1..v9 - anode-segments from the 1st to the 9th category;
4 - b1..b9 - anode-segments from the 1st to the 9th category;
5 - a1..a8 - anode-segments from the 1st to the 8th category;
6 - Grid of the 1st category;
7 - Grid of the 3rd category;
8 – Grid of the 5th category;
9 - Grid of the 7th category;
10 - Cathode, conductive layer of the inner surface of the balloon;
11 - Grid of the 9th category;
12 - Grid of the 8th category;
13 - Grid of the 6th category;
14 - Grid of the 4th category;
15 - Grid of the 2nd category;
16 - i1..i8 - anode-segments from the 1st to the 8th category;
17 - zh1..zh8 - anode-segments from the 1st to the 8th category;
18 - e1..e8 - anode segments from the 1st to the 8th category;
19 - d1..d8 - anode-segments from the 1st to the 8th category;
Connection of conclusions for the formation of numbers and signs on the IV-21 indicator:
Number 0 - conclusions 3, 18, 17, 19, 4, 5
Number 1 - conclusions 18, 3
Number 2 - conclusions 17, 19, 2, 5, 3
Number 3 - conclusions 17, 18, 2, 5, 3
Number 4 - conclusions 18, 3, 2, 4
Number 5 - conclusions 17, 18, 2, 4, 3
Number 6 - conclusions 17, 18, 2, 4, 5, 19
Number 7 - conclusions 18, 5, 3
Number 8 - conclusions 19, 18, 17, 2, 5, 4, 3
Number 9 - conclusions 18, 17, 2, 5, 4, 3
Decimal point from 1st to 8th digit - pin 16
Service point of the 9th category - pin 4
Horizontal bar - conclusion 2
Operating conditions of indicator IV-18 (type 1, 2):
Vibration loads: frequency range: 1–60 Hz acceleration max: 19.6 m/s2 (2 g)
Multiple impact loads: acceleration max: 147 m/s2 (15 g) impact duration: 15 ms
Ambient temperature: -45..+70 °С
Relative air humidity at Т=+25 °С, no more than 98% Relative air humidity at Т=+35 °С for execution “Т”, no more than 98%
Basic data of the IV-21 indicator:
Light Color: Green
The nominal brightness of the indicator of one digital digit is 300 cd/m2, the service digit is 175 cd/m2.
Filament voltage: 2.4V
Filament current: 35±5mA
Anode-segment current impulse total IV-21: 12 ± 8 mA
Grid voltage pulse: 27 V
Grid current pulse of one discharge: 2 ± 1 uA
Duty cycle: 10 ± 1.0
Minimum operating time: 5,000 h
The brightness of the indicator, changing during the minimum operating time, not less than: 100 cd/m2
Maximum allowable electrical mode of the IV-21 indicator:
The heating voltage is strictly within: 2.0–2.65 V
Maximum anode-segment voltage: 50 V
The highest grid voltage pulse: 50 V
The largest pulse current of the anode-segment: 1.0 mA
Recommendations for the use of the IV-21 indicator:
It is not recommended to operate the indicator when the heating circuit is powered by direct current. The heating circuit is preferably supplied with alternating current from the transformer winding with a midpoint serving as a common cathode output point.
The visible glow of the anode segment when the voltage is applied to the grid occurs at a positive potential of the anode segment of 2.5–3.0 V. To avoid possible illumination, the potential at the anode segment should not exceed 1.5–2.0 V. For complete removal the glow of the anodes-segments with a voltage applied to them, it is necessary to apply a blocking negative potential of at least 2 V (in absolute value) to the grid. It is allowed to operate the indicator at a heating voltage of 2.8 V; at the same time, the total operating time in this mode should not exceed 10% of the guaranteed operating time. Leads may be bent at a distance of at least 1 mm from the base of the indicator.