DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
These Beckman (Beckman acquired in 1973 Sperry Information Displays Division, Scottsdale, AZ) SP-750 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-750 Series display modules are recommended for these applications:
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• DC operation when zeros are not suppressed or blanked • Multiplexed operation when zeros are not suppressed or blanked when the following requirements can be met: 1. Minimum digit on times of 100 us 2. Minimum interdigit blanking of 125 us 3. Maximum refresh perios of 3 ms |
Ih case these requirements can't be met, the use of SP-350 Series display modules is recommended.
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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-751 |  |
Extra decimal point for left-most digit | |
| SP-752 |  |
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| SP-753 | Heathkit IC-2008, IC-2008A |  |
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| SP-754 |  |
Extra decimal point for left-most digit |
| Type | Products | Relationship | Comments |
| SP-730 | 0.33” Characters | ||
| SP-350 | Keep-alive Cathode | Multiplexed applications |
| Item | Min | Typ | Max | Unit | Comments |
| Anode Supply Voltage | 170 (1) |
200 | V | DC-Characteristics | |
| Anode-to-Anode Differential Voltage | 14 (2) |
V | " | ||
| Anode-to-Cathode Voltage Drop | 150 | V | " | ||
| Cathode Current - Per Segment | 250 | 330 | 495 | uA | " |
| Cathode Current - Decimal Point | 100 | 145 | 220 | uA | " |
| Cathode Current - Plus Sign | 492 | 650 | 975 | uA | " |
| Cathode Current - Minus Sign | 227 | 300 | 450 | uA | " |
| Power Dissipation - All segments lighted | 370 | mW | " | ||
| Anode Voltage Swing | 200 | 225 | V | Multiplex Characteristics | |
| Digit On Time | 100 | 200 | us | " | |
| Inter-digit Blanking Time | 125 | 150 | 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 170 volts
(210 volts for multiplexed operation). After the display is ionized, the
voltage drop is approximately 150 volts.
(2) Lighted cathodes on all
digits with independent current limiting. For bussed cathodes (multiplex
operation), 100 volts is permissible.
The Sperry SP-750 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-751 and SP-752 are using a 1.06" / 26.9 mm by 1.12” / 28.4 mm glass substrate with 18 connector pins in an irregular arrangement on the bottom of the display module.
The SP-753 and SP-754 are using a 1.59" / 40.4 mm by 1.12” / 28.4 mm glass substrate with 27 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 |
| 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.
