Manufacturer:  | Weston |
Model:  | 1294 |
Year:  | 1970 |
Schematic:  | RE |
| |
Functions:  | DCV |
Display:  | NIXIE |
Digits:  | 4.5 |
Logic:  | TTL |
|
Industrial panel meters made the transition from analog to digital in the early 1970's.
This is one of the few NIXIE-display models produced before such instruments settled in
to the use of LEDs for display.
The A-to-D converter is of the dual-slope integration type, implemented with discrete and SSI components.
The design impressively achieves this with a relative paucity of components, and packed into a small form factor.
The native range of the design is +/- 200.0 mV, auto-polarity is included.
Model options allowed for internal input configurations for other voltage and current ranges.
Overflow is indicated by a flashing of the display.
Bottom of case showing model options.
Analog / upper board with power supply and input amplifier.
Digital / lower board with integrator, counter and display.
- Unit Log -
Serial Number:  | 73902 |
Year of Manufacture:  | 1970 (IC date stamps of 7011 to 7039). |
Date of Receipt:  | 2006 |
State upon Receipt:  | OK physically, a little shaky functionally. |
Date:  | 2006 Mar |
Procedure:  | Cleaned. RE'd. |
Date:  | 2006 Mar 27 |
Symptoms:  | Socket pin for DP of LSD will not accept tube pin. |
Procedure:  | Socket pin removed. A couple of other pins have intermittent contact. |
Date:  | 2008 Mar 07 |
Symptoms:  | Display does not light up. |
Procedure:  | Anode supply not present.
Secondary of transformer is open.
Break in fine wire of secondary found on top of windings near where it connects
to more-solid lead.
Managed to scrape enamel off and get a lead extension to solder to it.
Resistance now measures around 2.2 or 3.3 K. |
Date:  | 2015 Nov |
Procedure:  | Design analysed, noted to be dual-slope integration. |