DC Power Supply: BK Precision 1671A

By Vivek T

    Resources

    Overview & Control Panel Layout

    The BK Precision 1671A is an analog-controlled triple-output DC power supply with digital LED readouts. It provides:

    • Main Variable Output: 0–30 V DC @ 0–5 A.
    • Fixed 5V Output: 5 V DC @ 0.5 A max.
    • Fixed 12V Output: 12 V DC @ 1.0 A max.

    Setting Up the Main Variable Output (0–30V)

    1. Power On: Flip the POWER rocker switch to I (ON).
    2. Disconnect Load: Ensure no wires are connected to the front output terminals.
    3. Set Target Voltage: Turn the VOLTAGE control knob clockwise until the digital VOLT display matches your desired input level (e.g., 9.0 V or 12.0 V).
    4. Set Current Limit (Safety Ceiling):
    • Turn the CURRENT control knob fully counter-clockwise to minimum.
    • Briefly short the main variable (+) Red and (-) Black terminals together using a thick jumper wire.
    • The CURRENT LIMITED red LED indicator will turn ON.
    • Turn the CURRENT knob clockwise until the digital AMP display reads your desired current limit (e.g., 0.20 A or 200 mA).
    • Remove the shorting jumper wire immediately. The CURRENT LIMITED LED will turn OFF.
    1. Connect Output: Connect banana-to-alligator leads from the variable (+) Red and (-) Black terminals to your circuit breadboard.

    Status Indicators & Troubleshooting

    Indicator StateConditionAction Required
    CURRENT LIMITED LED OFFNormal Constant Voltage (CV) operation. Delivered voltage equals knob setting.Circuit is operating safely within set limits.
    CURRENT LIMITED LED ON (Red)Constant Current (CC) mode triggered. Load resistance is drawing max set current.Check circuit for reversed components, short circuits, or incorrect resistor values.

    Using Fixed Auxiliary Outputs (5V and 12V)

    The BK Precision 1671A includes two independent, fixed-voltage terminal blocks located on the right side of the front panel:

    1. Fixed 5V Terminal: Delivers a constant 5.0 V DC up to 0.5 A. Ideal for standard TTL logic gates and 5V microcontrollers.
    2. Fixed 12V Terminal: Delivers a constant 12.0 V DC up to 1.0 A. Ideal for operational amplifiers, relay coils, or motor drivers.
    3. Connections: Connect your breadboard leads directly between the corresponding (+) colored jack and (-) Black GND jack.

    Note: The fixed 5V and 12V outputs feature internal foldback current limiting for overload protection, but their current limits are not manually adjustable via the front panel knobs.