DEC H7082 Power Supply Modules H7082-AB

Technical Dossier

Product Details And Specifications

DEC H7082 Series Technical Notes

The Evolution of H7082 Architecture

As DEC's VAX architecture matured through the VAX-11/750, VAX-11/780, and MicroVAX generations, the H7082 series was progressively adapted to support higher current demands from denser CPU and memory configurations. Compatibility across BA11, BA23, and BA123 enclosure families was maintained through standardized connector pinouts, though output current ratings and ripple specifications differ between sub-variants. Engineers maintaining mixed-generation DEC installations must verify the specific revision suffix before substitution, as cross-variant swaps without derating analysis can result in marginal voltage regulation under peak load.

DEC was acquired by Compaq in 1998, and subsequently by Hewlett-Packard in 2002. No new H7082-series units have been manufactured since the late 1990s. The entire series is now in end-of-life status, with all support obligations transferred to the third-party maintenance and surplus parts market.

H7082 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified members of the DEC H7082 power supply family. Each entry reflects a distinct hardware revision or output configuration. Functional descriptions are derived from DEC engineering documentation and field maintenance records.

Quality Control for the H7082 Range

The H7082 series presents specific refurbishment challenges due to its age profile and the failure modes characteristic of switching power supplies manufactured in the 1970s–1990s. DriveKNMS applies a structured test protocol to every H7082 unit processed:

Capacitor ESR and capacitance verification: All electrolytic capacitors are tested for equivalent series resistance and capacitance value. Units with capacitors outside ±20% of rated capacitance or with ESR exceeding manufacturer limits are recapped using modern long-life equivalents rated for 105°C operation.
Output rail regulation accuracy: Each output rail (+5V, +12V, -12V) is measured under no-load, 50% load, and full-rated load conditions. Regulation must remain within ±2% of nominal across the full load range.
Ripple and noise measurement: Output ripple is measured at full load using a 20 MHz bandwidth oscilloscope. Ripple exceeding 50 mV peak-to-peak on the +5V rail or 100 mV on the ±12V rails results in unit rejection or further repair.
Overcurrent protection verification: Each unit is tested for OCP trip point accuracy. The protection circuit must activate within the specified current window without nuisance tripping under normal load transients.
Thermal cycling and burn-in: Units are operated at full rated load for a minimum of 24 hours in a controlled thermal environment to screen for infant mortality failures in recapped or repaired assemblies.
Backplane connector inspection: Edge connector contacts are inspected under magnification and cleaned or re-tensioned as required to ensure reliable backplane mating in BA-series enclosures.