User Manual

Introduction
The EL series provides medium levels of power (up to 125 watts) in a compact and attractive
case style using linear regulation.
High resolution controls allow precise setting of voltage and current levels which are indicated on
accurate and highly legible digital meters.
Excellent line and load regulation is matched by very low noise and good transient response.
Improved power efficiency ensures that the units require no fan cooling.
The EL302D has two independent isolated outputs each with a 0 to 30V, 0 to 2A capability. The
outputs operate in constant voltage or constant current mode with automatic crossover and mode
indication. Each output has its own on-off switch. The outputs can be wired in either series or
parallel to provide voltages up to 60 volts or currents up to 4 amps. The EL302Tv has, in addition,
an Auxiliary ‘logic voltage’ output with a 2A current capability. This output can be preset between
1.5 volts and 5 volts via a front panel control.
The EL155, EL183, EL301, EL302, EL303 and EL561 are single output supplies capable of
supplying up to 15V/5A, 18V/3.3A, 30V/1A, 30V/2A, 30V/3A or 56V/1.1A respectively.
The EL series incorporates separate digital voltage and current meters on each output. The
meters use bright 14mm (0.56”) LED displays and have an update rate of 4 per second providing
near instantaneous response. Simultaneous metering of voltage and current provides accurate
information “at a glance” and avoids any possibility of misinterpretation. When an output switch is
set to “off”, the current limit setting is displayed enabling conditions to be set before the load is
connected. With the right-hand main output off the right-hand meters can be used to momentarily
display the preset Auxiliary voltage and current limit.
The EL series has been designed to meet the stringent requirements of relevant IEC standards
for safety and EMC. All outputs are intrinsically short circuit proof, and are protected against
external voltages and reverse currents.
Specification
MAIN OUTPUTS
Voltage Range: 0V to 15V minimum (EL155)
0V to 18V minimum (EL183)
0V to 30V minimum (EL301, EL302, EL303, EL302D, EL302Tv)
0 to 56V minimum (EL561)
Current Range: 0A to 1A minimum (EL301)
0A to 1.1A minimum (EL561)
0A to 2A minimum (EL302, EL302D, EL302Tv)
0A to 3A minimum (EL303)
0A to 3.3A minimum (EL183)
0A to 5A minimum (EL155)
Voltage Setting: By coarse and fine controls.
Current Setting: By single logarithmic control.
Operating Mode: Constant voltage or constant current with automatic cross-over.
Output Switch: Electronic. Preset voltage and current displayed when off.
Output Terminals: Universal 4mm safety binding posts on 19mm (0.75”) pitch.
Output Impedance:
Typically <5mΩ in constant voltage mode.
Typically >50kΩ in constant current mode.
Output Protection: Outputs will withstand forward voltages of up to 20V above the rated
output voltage. Reverse protection by diode clamp for currents up to 3A.
Load Regulation: <0.01% of maximum output for 90% load change.
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