HP 6205C - Dual DC Power Supply

HP 6205C — Dual DC Power Supply

Dual Outputs • Linear Regulated • Independent or Tracking • Classic HP Lab Supply

Purpose & Capabilities

A precision dual-output linear DC power supply designed for:

• Analog circuit development

• Op‑amp and audio experiments

• Multi‑rail digital logic prototyping

• Sensor and instrumentation testing

• General electronics bench work

The HP 6205C is known for clean, low‑noise output, excellent regulation, and rock‑solid reliability typical of HP’s 1970s–1990s lab gear.

Access Level

• General Member Use with Training

• No reservation required

• Only authorized volunteers may open or calibrate the unit

• Internal capacitors store dangerous energy — do not service internally

Specifications

(These are the standard HP 6205C factory specs.)

Dual Outputs

• Output A:
  0–40 V @ 0–0.5 A

• Output B:
  0–20 V @ 0–1 A

Operating Modes

• Independent:
  Each output behaves as a separate supply

• Tracking:
  Output B tracks Output A (useful for dual‑rail circuits)

• Series:
  Combine outputs for higher voltage

• Parallel:
  Combine outputs for higher current (within limits)

Performance

• Type:
  Linear regulated

• Ripple & Noise:
  Very low (millivolt‑level)

• Load Regulation:
  Excellent

• Cooling:
  Passive (no fan — silent operation)

• Output Terminals:
  Heavy binding posts

• Protection:

  • Current limiting

  • Thermal protection

  • Overvoltage protection (depending on revision)

Before You Begin

• Inspect the supply:

  • Ensure binding posts are clean and tight

  • Verify leads are rated for the intended current

  • Check that voltage knobs are turned down

• Choose operating mode:

  • Independent
    for two separate circuits

  • Tracking
    for ± rails

  • Series/parallel
    only if you understand the configuration

• Double‑check polarity

• Confirm your load can safely handle the selected voltage and current

Operating Guidelines

Setting Voltage & Current

• Use the coarse and fine knobs for precise voltage control

• Set current limit before connecting your load

• Monitor front‑panel meters during operation

• Avoid sudden large changes in voltage while connected to sensitive circuits

Connecting Loads

• Use proper gauge wire

• Ensure connections are secure — loose connections can arc

• For inductive loads:

  • Expect voltage dips

  • Use flyback protection if needed

During Operation

• The supply is silent — no fan

• It may get warm under load; this is normal

• Avoid running at maximum current for extended periods

After Use

• Turn voltage down to zero

• Turn off the supply

• Disconnect leads

• Coil cables neatly

Supported Use Cases

Approved:

• Op‑amp circuits

• Audio electronics

• Sensor testing

• Logic circuits

• LED drivers

• Analog prototyping

• Dual‑rail circuits (±12 V, ±15 V, etc.)

Not approved:

• Motors

• High‑current loads

• Battery charging

• Anything requiring more than 40 V

• Experiments with exposed high‑current bus bars

Care & Etiquette

• Do not block ventilation slots

• Do not exceed the current rating of the leads

• Never intentionally short the output

• Report:

  • Burning smell

  • Output instability

  • Meter flicker

  • Excessive heating

Common Issues & Troubleshooting

• Supply drops into current limit

  • Load is drawing more current than allowed

• Voltage sag

  • Load may exceed power capability

• Output unstable

  • Check connections; inspect leads for heating

• Tracking mode not behaving correctly

  • Verify mode switch and knob positions