DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
These Beckman (Beckman acquired in 1973 Sperry Information Displays Division, Scottsdale, AZ) SP-350 Series display modules are raised-cathode, planar-gas-discharge devices. Units of equal character height can be stacked vertically or horizontally to make any desired message field while maintaining continuous inter-character spacing.
The SP-350 Series display modules were designed for interfacing with MOS/LSI and are recommended for these applications:
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DC or Multiplexed operation when zeros are not suppressed or blanked DC or Multiplexed operation when zeros are suppressed or blanked |
The SP-350 Series display modules offer improved electrical characteristics compared to the previous SP-750 Series. These improvements include:
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Reduction of the anode voltage required Reduction of the cathode current required Reduction of the blanking requirements |
In addition, a keep-alive cathode provides an internal ion source that reduces re-ionization time to less than 30 microseconds, allows zero-suppression, and improves the operation of the display modules in dark environment and at low temperatures.
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0.55/14.0 mm Characters Seven-Segment Digits with Right-Hand Decimals Continuous Uniform Segments, Orange (Neon Glow) Wide 130° Viewing Angle 40 feet/12 m Viewing Distance 0.531/13.5 mm Character Spacing 10 years Life Expectancy |
| Type | Products | Digits | Comments |
| SP-351 |  |
Extra decimal point for left-most digit | |
| SP-352 |  |
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| SP-353 | Heathkit IC-2100 |  |
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| SP-354 |  |
Extra decimal point for left-most digit |
| Type | Products | Relationship | Comments |
| SP-730 | 0.33 Characters | ||
| SP-750 | Predecessor | DC applications |
| Item | Min | Typ | Max | Unit | Comments |
| Anode Supply Voltage | 160 (1) |
180 | V | DC-Characteristics | |
| Anode-to-Anode Differential Voltage | 14 (2) |
V | " | ||
| Anode-to-Cathode Voltage Drop | 135 | V | " | ||
| Cathode Current - Per Segment | 130 | 300 | 420 | uA | " |
| Cathode Current - Decimal Point | 65 | 135 | 190 | uA | " |
| Cathode Current - Plus Sign | 260 | 585 | 820 | uA | " |
| Cathode Current - Minus Sign | 120 | 270 | 380 | uA | " |
| Cathode Voltage - Keep Alive | 0 | -80 | V | " | |
| Cathode Current - Keep Alive | 10 | 50 | uA | " | |
| Power Dissipation - All segments lighted | 350 | mW | " | ||
| Anode Voltage Swing | 160 | 180 | V | Multiplex Characteristics | |
| Digit On Time | 50 | 200 | us | " | |
| Inter-digit Blanking Time | 40 | 50 | us | " | |
| Refresh Period | 3 | ms | " | ||
| Cathode Voltage Swing | 30 | 50 | 120 | V | " |
| Cathode Bias Voltage | 30 | 50 | 120 | V | " |
| Operating Temperature | 0 | 70 | °C | ||
| Storage Temperature | -55 | 125 | °C |
(1)
The minimum recommended voltage required to ionize the display is 160 volts.
After the display is ionized, the voltage drop is approximately 135 volts.
(2) Lighted cathodes on all
digits with independent current limiting. For bussed cathodes (multiplex
operation), 90 volts is permissible.
The Sperry SP-350 Series Information Displays are neon gas-discharge devices that use seven segments to form and desired number from 0 to 9 and some alphabetic characters. The desired symbol is formed by application of a DC voltage between an anode and the appropriate cathode segments of the display. By selectively addressing the desired segment combinations, the neon gas surrounding the segment becomes ionized exhibiting a soft orange glow and displaying the desired number or letter.
Each character or digit is comprised of seven segments or cathodes and a decimal point. Each digit has a separate anode imprinted on the faceplate. Voltage is applied to the anode via a separate connector pin in the substrate.
The SP-351 and SP-352 are using a 1.06" / 26.9 mm by 1.12 / 28.4 mm glass substrate with 20 connector pins in an irregular arrangement on the bottom of the display module.
The SP-353 and SP-354 are using a 1.59" / 40.4 mm by 1.12 / 28.4 mm glass substrate with 30 connector pins in an irregular arrangement on the bottom of the display module.
| Pin | Pol. | Function |
| 1 | C | A Segment / Not used |
| 2 | C | B Segment |
| 3 | C | C Segment |
| 4 | C | D Segment / Extra DP |
| 5 | C | E Segment / Minus Segment |
| 6 | C | F Segment / Plus Segment |
| 7 | C | G Segment / Not used |
| 8 | C | Decimal Point |
| 9 | A | Digit |
| 10 | C | Keep-alive Cathode |
| The Cathode of the Segments A-G and Right-Hand Decimals and the Anode of the Digits are connected to the display in the pictured way. |
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Burroughs, Sperry and Panaplex are trademarks of Unisys Corporation.
If you have additions to the above datasheet please email: joerg@datamath.org.
© Joerg Woerner, March 25, 2023. No reprints
without written permission.
