File:Ferranti Archives TV-FER-SCH-159 Sinclair TV test box power supply schematic, 12 October 1983.pdf
Summary
[edit | edit source]Ink schematic of the power supply in the Sinclair TV test box, which powers the ZN401 under test through its pin 12 ("Vcc pin 12") from a +12 V rail. The title block is dated 12 October 1983 and the sheet carries the typed label "TV TEST ISSUE 1 30/9/83". Four ZN458 references in series give a reference voltage that a 1K preset sets for 6.5 V; relays RL5, RL6 and RL7 each switch in a 5K preset to pull it down to 4.5, 4.2 or 3.9 V. Two emitter followers (a ZTX300 driving a ZTX450) pass the reference to the device, and a ZTX300 on the "high for supply off" input shorts the reference to switch the supply off. The followers' collector feed comes either through 62 ohms and the contact of relay RL8, or from a ZTX500 constant-current source with a 50 ohm preset marked "set 35 mA", so with RL8 open the device current is limited to 35 mA. A ZN424 comparator watches the collector feed and drives a red LED and a logic flag, first labelled HF6 and then relabelled HF3'; the test 3 circuit on TV-FER-SCH-163 has a matching input. A second follower output, "B2 Vcc", is marked not connected. The RL6 preset is labelled 4.2 V here, while the relay table TV-FER-DAT-167 gives 4.4 V. The board layout is TV-FER-SCH-157. Part of the Ferranti Archives 2026.
Archive record
[edit | edit source]| Catalogue ID | TV-FER-SCH-159 |
|---|---|
| Date | 12 October 1983 (title block); typed label "TV TEST ISSUE 1 30/9/83" |
| Origin | Ferranti |
| Document type | Schematic |
| Device or subject | Pocket TV Test Box |
| Catalogue description | A pen drawn schematic of the Sinclair TV Test Box PSU |
| Original file name | {{{filename|}}}
|
| Found in | TV-FER-FOL-168 |
| Pages | 1 |
Source
[edit | edit source]Ferranti Archives 2026, original scan on Google Drive.
Author
[edit | edit source]Ferranti Electronics Limited
Licence
[edit | edit source]Ferranti Archives 2026: source and terms of use
This scan is part of the Ferranti Archives 2026, a collection of Sinclair-related documents from Ferranti's files, catalogued in 2026 and released through the Happy Little Diodes YouTube channel (video, catalogue). The archive presents the documents for preserving and archiving material of historical interest, and for non-commercial, educational and archival research. Its terms state that consent is strictly limited to non-commercial use, and that any commercial exploitation of the documents or their contents, including use in connection with the manufacture, marketing or sale of goods, is strictly prohibited by Sky UK Limited.
Copyright remains with the rights holders. The file is not freely licensed and is hosted here for preservation and repair reference only, under the archive's terms. Personal information was redacted by the archive before release; if you find any that remains, please tell [email protected].
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| Date/Time | Dimensions | User | Comment | |
|---|---|---|---|---|
| current | 10:40, 18 October 2026 | 0 × 0 (17.38 MB) | Josh (talk | contribs) | Ferranti Archives 2026: TV-FER-SCH-159 |
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