The RCA Selectron -- LM Ericsson Register Tube



The LME "memotron" was a 20-bit digital storage register tube. It can be considered to be a one-dimensional variant of the RCA Selectron tube in that it had a single cathode flooding multiple targets, each of which relied on secondary electron emission to maintain a bistable electrical potential.

Olaf Sternbeck
Wolfram Erhard Max Uhlmann
Walter Emil Wilhelm Jacob
Carl Gunnar


Telefonaktiebolaget LM Ericsson,
 Stockholm, Sweden

First US patent application: 29 April, 1952
Granted: 23 July, 1957


 Side view of structure, envelope, base and pins
Electronics, January 1955 article
Electronics, January 1955 article























Copyright 1955 McGraw-Hill Publishing Co.
All rights reserved




US Patents
US Patents






Cover of LM Ericsson 1952 Annual Report

LM Ericsson 1952 Annual Report
LM Ericsson 1952 Annual Report excerpt

Link to complete document at: www.ericsson.com





"Two new types of electron tubes, a simplified trochotron and a memotron, have been completed during the year. They will be utilized for the calculation of fast pulses and respectively, for some special features in telephone and electrical counters."

"Memotron designed for special functions in telephone and electrical counters."








Copyright 1952 Telefonaktiebolaget LM Ericsson.
All rights reserved
Used by permission