Gas Discharge Tubes

Counting tubes index page

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Mullard Cold Cathode Indicator Tubes

Abbreviations: dp = decimal point, LH = left hand, RH = right hand.
Char. = character, Rec. = recommended, Maint = maintenance. HT = High Tension (ie., B+).

Mullard Type No.	Bulb colour	Display	Char. Height /mm	Min. HT /V	Maint. Voltage	Rec. Cathode Current /mA	Base & view
ZM1020	red	0123456789	15.5	170	140	2.0	B13B end view
ZM1022	clear
ZM1021	red	A V Ω + - % ~
ZM1023	clear
ZM1024	red	c/s kc/s Mc/s ns μs ms s
ZM1026	red	½
ZM1040	red	0123456789	30	170	140	4.0	B13B side view
ZM1041	red	- +	20
ZM1080	red	0123456789	13	170	140	2.0	Wire ended. Side view.
ZM1082	clear
ZM1081	red	- + ~	10.5
ZM1083	clear
ZM1162 (rectangular bulb)	clear	0123456789	15.5	170	140	2.0	14 pin special. end view.
ZM1170	Red	0123456789	15.5	170	140	2.0	Wire ended. Side view.
ZM1172	Clear
ZM1174	Red	0123456789 LH dp
ZM1175	Clear
ZM1176	Red	0123456789 RH dp
ZM1177	Clear
ZM1230	Red	0123456789	15.5	170	140	2.0	Wire ended. Inverted side view.
ZM1232	Clear

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ZM1080 Data (Mullard data sheet December 1968)

Limiting Values (Absolute) Cathode current (each digit). Max average: (Max averaging time = 20 ms) 3.5 mA Max. Peak 12 mA Min. average during conduction: 1.5 mA Bulb Temp: Max: +70 °C Min (see note 2) -50 °C

Symbol

Pulse Operation Max cathode current Peak: 12 mA Average (Averaging time = 20 ms): 2.5 mA Min cathode current for satisfactory display, average 0.8 mA Pulse duration Max 20 ms Min 100 μs Anode to cathode maintaining voltage: see graph Extinction Requirements Max anode to cathode voltage to ensure extinction: 115 V Life Expectancy (assuming recommended operating conditions and room temperature). Continuous display of one digit (see note 1): >5000 hours Sequentially changing the display from one digit to the next every 100 hours or less: >30 000 hours

Mounting Position:
The numbers are viewed through the side of the envelope. The numbers will appear upright (within ±3°) when the tube is mounted vertically.

Operating Notes:

1) The life expectancy figures given above relate to operation with DC cathode currents between 1.5 and 2.5 mA and at all permitted pulsed cathode currents. When a DC cathode current range of 1.5 to 3.5 mA is used, the life expectancy exceeds 3000 hours with continuous display of one digit.

2) For bulb temperatures below 0°C, the life expectancy of the tube is substantially reduced.

3) The leads are tinned and may be dip-soldered to a minimum of 5mm from the seals at a solder temperature of 240°C for a maximum of 10 seconds.

4) Care should be taken not to bend the leads nearer than 1.5mm from the seals.

5) The tube may be soldered directly into the circuit but heat conducted to the glass-to-metal seals should be kept to a minimum by the use of a thermal shunt.

Information on the use of pin 4 (primer pin)

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Gas Discharge Tubes

Counting tubes index page