KPSB-3A Access Control Power Supply, 12V DC 3A, Battery Backup, NC/NO Relay

Regulated 12V Supply for Door Access Systems

The KPSB-3A access control power supply delivers a regulated 12V DC output at 3A continuous current for small door access installations. It accepts 220V AC input and provides NC/NO relay contacts, GND, +12V, PUSH and Control terminals for direct wiring to controllers and electric locks. A built-in battery bay accepts a 12V 7Ah SLA battery for standby operation during mains failure.

The linear supply maintains steady voltage under load and includes automatic overcurrent protection. Output ripple stays low enough for sensitive readers and lock controllers. A 0–10 second delay adjustment controls lock release timing, and the metal enclosure measures 214 x 168 x 72 mm for wall or cabinet mounting. The unit supplies up to 5A momentary current for lock inrush.

Front-panel terminals use screw clamps rated for 1.5 mm² conductors. The enclosure includes a keyed latch and conduit knockouts for cable entry. Operating temperature spans -10°C to 50°C, and the transformer-based design tolerates input fluctuations of ±20%. A sealed lead-acid battery sits inside the housing and charges through a current-limited circuit. The supply suits single-door controllers, magnetic locks, strikes and exit buttons in commercial and residential sites.

Key Features

• 12V DC 3A Regulated Output
  The linear regulator holds 12V DC at 3A continuous load for readers, controllers and electric locking hardware.

• Battery Backup Chamber
  An internal bay accepts a 12V 7Ah SLA battery and charges it through a current-limited circuit for standby power.

• Multi-Terminal Interface

  • NC/NO dry contacts for lock control
  • GND and +12V auxiliary power terminals
  • PUSH input for exit button wiring
  • Control input for remote trigger

• Adjustable Lock Delay
  A trim pot sets release timing from 0 to 10 seconds to match strike and maglock behaviour.

• Overcurrent Protection
  Automatic current limiting protects the transformer and connected devices during short circuits or lock inrush.

• Steel Enclosure
  The 214 x 168 x 72 mm metal housing includes keyed latch, conduit knockouts and wall-mount tabs.

Specifications

What’s in the Box

• KPSB-3A power supply unit

• Mounting screws

• Terminal wiring diagram

Why Choose the KPSB-3A Supply

• The 3A continuous rating powers a controller plus an electric lock from one enclosure.

• Battery backup keeps the door system operational through short mains outages.

• NC/NO relay contacts simplify wiring to strikes, maglocks and exit buttons.

• The adjustable delay matches lock release timing without external timers.

• A steel housing with keyed latch protects terminals in public-facing cabinets.

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