Constant Voltage / Current Limiting Power Supply


The RA Series power supplies provide SCR pre-regulated linear output with high power, good regulation and low ripple.  They find application both in the laboratory and in systems where both versatility of operation and a high degree of regulation is required. These power supplies are provided with rear barrier terminal strip for ease in output wiring.  The RA Series operates as a constant voltage (CV) power supply for excellent regulation and has built in current limiting (CL) for protection of the external load.


  • Remote Voltage Programming
  • Remote Sensing
  • Series/Parallel Operation
  • Rear Barrier Strip
  •  1 mV RMS Ripple
  • 10 Turn Voltage Control
  • 10 Turn Current Control
  • Optional IEEE-488, LAN, RS485, RS232 Control
linear power supply photo


3 ½” Model

RA20-15A 0-20 V0-15 A
RA40-10A 0-40 V0-10 A
RA60-7A 0-60 V0-7 A
RA125-3.2A 0-125 V0-3.2 A

5 ¼” Model

RA20-25A 0-20 V0-25 A
RA40-20A 0-40 V0-20 A
RA60-14A 0-60 V0-14 A
RA125-6.5A 0-125 V0-6.5 A

7” Model

RA40-30A 0-40 V0-30 A
RA60-20A 0-60 V0-20 A
RA125-10A 0-125 V0-10 A
RA250-5A 0-250 V0-5 A

8¾” Model*

RA40-50A 0-40 V0-50 A
RA60-30A 0-60 V0-30 A
RA125-20A 0-125 V0-20 A
RA250-10A 0-250 V0-10 A

10½” Model*

RA25-100A 0-25 V0-100 A
RA40-70A 0-40 V0-70 A

*220VAC 50/60 Hz 1 Phase Standard


Input: 115 VAC or 220 VAC ±10% 50/60 Hz Single Phase depending on the model.

Output: See specific model in table.
The output is floating and either side may be grounded.

Load Regulation: 0.01% of the maximum rated voltage for a full load step.

Line Regulation: 0.01% of the maximum rated voltage for a line change within specified input voltage range.

Ripple: ≤1 mV RMS.

Response Time: The output voltage is within regulation limits in less than 100 microseconds for a  ½ load step. The output voltage will remain within regulation limits for input line step within specified voltage range.

Remote Sensing: Units provided with remote sense terminals at the rear for regulation at the point of load.

Remote Programming: All units are voltage programmable at approximately 1000Ω / Volt.

Series / Parallel Operation: Two or more units may be operated in series. Two units of the same voltage and current may be operated in parallel.

Temp. Coef.:  0.02% / °C

Stability:  Better than 0.05% / 8 hours at constant line, load and temperature after ½ hour warm up.

Operating Temperature:  0°C to +60°C at any combination of line, load and temperature without the need for external cooling.

Terminations:  Barrier strip terminals are provided at the rear for AC input, output, sensing, remote programming, slaving and ground.

Protection: The power supply is protected by a fuse in the input line. 8¾” & 10½” models are protected by a circuit breaker. The output of the supply is protected by means of a fully adjustable current limiting circuit.

Panel Controls: Voltmeter, Ammeter, 10 turn voltage control, 10 turn current control, pilot light and ON/OFF switch. The voltage and current control is fully adjustable from 0 to Full Range by means of 10 turn panel potentiometers.

Finish: The standard front panel finish is light blue.

Size: 8¾” & 10½” Models: 19“ (WIDE) x 22” (DEEP)
All Other Models: 19” (WIDE) x 16½” (DEEP)


23-Wire Line Cord Instead of Barrier Terminal Strip for Input
6Over Voltage Protection
27Chassis Slides
29Optional 220 VAC Input
36Voltage/Voltage Programming (0-10V = Full Rated Output Voltage)
52Voltage/Current Programming (0-10V = Full Rated Output Current)
62 3½ Digit Digital Meters
85Voltage/Voltage Programming (Isolated Input 0-10V = Full Rated Voltage)
90 Voltage/Current Programming (Isolated Input 0-10V = Full Rated Current)
108RS232 Control with Readback
110RS485 Control with Readback
112IEEE-488 Control with Readback
123RJ45 Control with Readback