Keithley 247 DC Power Supply

The Keithley 247 is a precision-regulated linear DC power supply delivering 0 to 3 kV DC at up to 6 mA for high-voltage measurement applications. This unit combines AC-to-DC conversion with a solid-state DC converter topology, generating stable, low-noise outputs suitable for sensitive instrumentation. Its fully encapsulated high-voltage assembly ensures arc-free operation across demanding test environments. The 247 excels in photomultiplier tube characterization, resistivity measurements, ion chamber biasing, and radiation detection systems. It pairs directly with Keithley electrometers and picometers, providing the regulated bias voltage these instruments require. Polarity selection - positive or negative with respect to chassis - accommodates varied circuit topologies.

Technical Specifications Output Performance

Voltage: 0 to 3 kV DC

Maximum current: 6 mA DC

Power output: 18 W

Accuracy: ±0.25% of setting + 1.5 V DC (1% to 100% of max voltage)

Dial resolution: 200 mV graduations

Stability: ±0.01% of setting per hour

Line regulation: 0.001% voltage change per 10% line variation

Load regulation: 0.005% voltage change from no-load to full-load

Ripple and noise: 3.5 mVrms, 10 mVp-p at 3 kV / 6 mA; 1 mVrms, 3 mVp-p at 1 kV / 1 mA (10 Hz to 100 kHz)

Settling time: 4 seconds to ±1 V with full resistive load Input Power

AC voltage: 90–125 V / 180–250 V selectable

Frequency: 50–60 Hz

Consumption: 130 VA Environmental

Operating temperature: 0°C to 50°C

Operating humidity: 0% to 80% RH (up to 35°C)

Storage temperature: −40°C to 75°C

Key Features

Selectable positive or negative polarity

Short-circuit proof with arc-protected, self-restoring design

MHV Type UG931/U rear-panel output connector

Compact 19 in × 3.5 in × 10.75 in form factor (483 mm × 89 mm × 273 mm)

Four rack-mount holes; bench feet included

Weight: 5.9 kg (13 lbs)

Typical Applications

Photomultiplier tube bias and characterization

Resistivity and conductivity measurements

Ion chamber operation

Radiation detection systems

Precision electrometer biasing

Compatibility & Integration Ship includes UG932/U mating connector and instruction manual. Mounts in standard 19-inch racks or operates on bench with supplied feet.