We recommend the PLA series loads to replace a PL series device. Find a function and command comparison here.


PL Series

  • Features
  • Details
  • Type Overview


• Voltage up to 400 VPL Serie
• Currrent up to 150 A
• Power 500 W ... 1,500 W
• Short-time overload capacity
• Current and resistance mode
• Dynamic loads
• SCPI programming with measurement function
• Electronic protection
• Analog measurement output for voltage, current and power
• Analog control input


Operating Modes

The devices have constant-current and constant-resistance operating modes in both static and dynamic operation. If fitted with an RS-232  or GPIB interface, software-controlled constant power control is possible. The manual setting of the load values takes place via two precise  ten-turn potentiometers. Switch from value A to value B by a keystroke.

Dynamic Operation

In dynamic mode the inbuilt modulator performs the switch between the setpoints A and B. For each load level it is possible to set a corresponding pulse duration  of 0.5 ms ... 500 milliseconds. In addition, pulse-pause ratios can be varied within broad time range. Switching between the two load levels can also be via the Analog I/O Interface at all levels between 3 V and 30 V.

Protective Devices

  • Overcurrent protection
  • Overpower protection
  • Overtemperature protection
  • Protection of the GND lines at the Analog I/O interface

If a protected value is exceeded the respective display flashes.

Overload Capacity

The type spectrum comprises three power classes with 500 W, 1000 W and 1500 W continuous load capacity. Depending on the model the devices have temporary overload capacity. The level and duration of the possible overload depends on the operating temperature of the power stage.
Therefore the device can also be used for significantly higher power tasks.

Analog Control

The control of the load current can be via an analog signal with optionally 0 ... 5 V or 0 ... 10 V.

Analog Measuring

Standard Analog I/O Interface with 0 ... 10V level for:

  • Input voltage
  • Load current
  • Power consumption
  • Nominal current
  • Master-Slave circuit


The unit is air-cooled with a two-phase temperature controller. 

Interfaces (optional)

  • RS-232 + system bus
  • GPIB + RS-232 + system bus
  • Smart-LAN (Ethernet-RS-232-Converter)

Configuration of a Multichannel System

For control of additional devices via the GPIB or RS-232 interface of the primary device, any number of devices can be connected via the system bus interface (Option PL01 in all other devices). Despite the shared interface, the devices are electrically isolated from one another and can be operated with potential differences  of up to 125 V.

Factory Calibration Certificate

A free Factory Calibration Certificate (FCC) is supplied with the devices. The FCC meets the requirements according to DIN EN ISO 9000ff. This calibration certificate documents the traceability to national standards to illustrate the physical device in accordance with the international System of Units (SI). Within the warranty period we calibrate a second time for free.


--> Conditions for a second free calibration


The recommended calibration interval is 2 years.

Software Tools

The H&H Homepage has a program library for Windows with a control tool and LabVIEW drivers.


We supply a User Manual as pdf file and printed General Safety Instructions, each in German and English.


Type Overview