Dekatron

A counting tube, other names are Dekatron (because they can usually a decade count ) and Trochotron, is a special tube ( the electron tube or a tube filled with gas and glow discharge ), which may include by deflecting an electron beam or by using glow discharges and their negative differential- internal resistance. Such Zählröhren are no longer used today.

Zählröhren with glow discharge

As a rule, ten glow and displaying cathode are housed in the tube which, separated by insulating fittings, however, be jointly supplied, an anode face. When a trigger pulse is generated at an auxiliary electrode enters a glow discharge between the cathodes. The discharge jumps from one cathode to the next.

The inner structure is designed such that

• Only one cathode lights
• The discharge for triggering changes in the predetermined order. An example is the CM 1070, it may include up to 5 kHz.

Zählröhren with cathode ray

These tubes also indicate, however, a fluorescent phosphor is required for this. An example is the type E1T who can count to ten. Maximum counting frequency is 30 kHz.

The 6710 can store up to 10 kHz ( under suitable conditions to about 2 MHz) quick count. It requires a series-connected flip-flop.

Use

Such Zählröhren were among other early computers ( Harwell Dekatron ), counters, timers and short - along with counter tubes - used for event number display in radioactivity measuring instruments.

Several tubes were connected together to form multi-digit counters. Some can count on in both directions.

References and links

• Notes to Dekatrons with pictures of different types
• Detailed description of a built at the TU - Berlin Geiger counter with decadal Zählröhren E1T