JRC, NBD-577A Power Supply Unit

The JRC NBD-577A Power Supply Unit is a dedicated AC-to-DC power converter manufactured by Japan Radio Co., Ltd. (JRC), a leading name in marine electronics.

Its primary function is to convert ship’s AC mains voltage into stable 24V DC power to operate various JRC marine navigation and communication equipment. While often sold as a standalone power supply, it is particularly known for being an integral component of older JRC Automatic Identification Systems (AIS) like the JHS-180 and JHS-182 AIS units, as well as other JRC equipment requiring a reliable 24V DC source.

Being a JRC product, the NBD-577A is built to marine-grade standards, ensuring robustness and reliable performance in the challenging maritime environment. It typically supports a range of AC input voltages (e.g., 100-120V AC or 200-240V AC) and provides a specific DC output, commonly around 24V DC at a maximum current of 5.5A.

Technical Specification

Input (AC):

Voltage: The unit is designed for dual-range AC input, selectable or automatically adjusting:
- 100-120 VAC
- 200-240 VAC
Frequency: 50/60 Hz

Output (DC):

Voltage: 24 VDC (Nominal)
Current Capacity: 5.5 Amps (Maximum)
- This current output is typical for powering JRC AIS units (like the JHS-180/182) and other associated equipment.

Protection Features (often built-in):

Over Voltage Protection (OVP): Typically around DC +27V to +30V, to protect connected equipment from excessive voltage.
Over Current Protection (OCP): Usually around 9.5A to 10.0A, to prevent damage from excessive current draw.
Automatic Changeover: When connected to both AC mains and a 24V DC battery backup (ship’s battery), the NBD-577A can automatically switch from AC to DC power in case of an AC power interruption, ensuring continuous operation of critical equipment.

Physical Specifications:

Manufacturer: Japan Radio Co., Ltd. (JRC)
Weight: Approximately 9.25 kg (20.4 lbs)
Dimensions (Approximate, as per some documentation for related JRC systems):
- Width: 425 mm
- Depth: 396 mm
- Height: 75 mm
Mounting: Designed for internal mounting in a suitable enclosure or rack.

Environmental Conditions:

As a marine-grade power supply, it’s built to operate within a specific range of temperatures, humidity, and vibration, suitable for onboard ship installations. (Specific temperature/humidity ranges would be detailed in the full manual for the associated equipment like the JHS-180/182 AIS).

Compatibility:

Often an optional or standard power supply for JRC JHS-180 and JHS-182 AIS systems.
Can be used with other JRC equipment requiring a stable 24V DC power source within its current capacity.