Cathodes of display tubes wired in parallel achieve input switching simplification of a Nixie tube display system. Use of time- shared logic energizes the appropriate anode and inhibits all unnecessary cathodes

Gray, J.

English

NASA Technical Reports Server

	November 1966	 Brief 66-10512 
•icy V
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Nixie Tube Display Unit Employs Time-Shared Logic 
p______________	 Sync. Pulse I
Adv. Scaler I  Clear & Store	 Ring of Seven Scaler J 
Digits	 Ii  121314151617 
	
Input 1	 -	 Nixies	
.-
Register 
4 Bit	 Decode 
0 Input	 Memory	 and	 _A I I 
Register  S	 input n 0 Selector	 (BCD) Inhibit Drivers 
The problem: 
To achieve input switching simplication of a Nixie 
tube display system. In conventional readout devices, 
Nixie display tubes are connected so all anodes of 
all tubes are continuously energized. Events are 
channeled to the particular Nixie display unit for 
portrayal. This method requires that each Nixie unit 
have all of its cathodes individually wired to the event 
generator, resulting in cluttered circuitry. 
The solution: 
Wire the cathodes of the display tubes in parallel. 
Use time-shared logic to energize the appropriate 
anode and inhibit all unnecessary cathodes. 
How it's done: 
The system consists of an anode scaler ring, a 4-bit 
memory register, a master pulse generator, and cath-
ode inhibit circuits. All of the corresponding nu-
meric cathodes of seven display tubes are connected 
in parallel. The anodes are connected to a seven 
scaler ring which turns each anode on for 140 micro-
seconds, stepping each anode through the ring and
repeating the sequence indefinitely. A scaler output 
consists of an endlessly repeating train of 28 serial 
bits (7 digits X 4 bits per digit). The cathodes are 
returned to ground through a circuit which can in-
hibit any unneeded element as-determined by the digit 
stored in a 4-bit memory register. A synchronization 
pulse from the master pulse generator causes the 
memory register to store and clear the digits in phase 
with the advance of the anode scaler. This arrange-
ment makes it possible to display seven decades of 
data by serially reading the individual digits into the 
memory register and synchronizing the anode scaler 
advance to correspond to the digit being read. 
Notes: 
1. The resulting display repetition rate of approxi-
mately 1000 cps completely eliminates visible 
flicker, while the intensity appears comparable to 
normal operation. The device provides substantial 
component savings over full-time parallel systems, 
while achieving input-switching simplification. 
(continued overleal) 
This document was prepared under the sponsorship of the Atomic 	 liability resulting from the use of the information contained in this 
Energy Commission and/or the National Aeronautics and Space document, or warrants that the use of any information, apparatus, 
Administration. Neither the United States Government nor any per- 	 method, or process disclosed in this document may not infringe pri-
son acting on behalf of the United States Government assumes any vately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19660000510 2020-03-11T17:44:10+00:00Z
2. The device has been operating for 2 1/2 years and	 Patent status: 
has required no maintenance.	 Inquiries about obtaining rights for commercial 
3. Inquiries concerning this innovation may be di- 	 use of this innovation may be made to: 
rected to:	 Mr. George H. Lee, Chief 
Office of Industrial Cooperation	 Chicago Patent Group 
Argonne National Laboratory 	 U.S. Atomic Energy Commission 
9700 S. Cass Avenue	 Chicago Operations Office 
Argonne, Illinois 60439	 9800 S. Cass Avenue 
Reference: B66-10512	 Argonne, Illinois 60439
Source: J. Gray
Chemistry Division
(ARG-117)
•1 
•: 
Brief 66-10512	 Category 01


Nixie tube display unit employs time-shared logic

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