PeakTech 2275/2280 Programmable DC Electronic Load

Introduction

The PeakTech 2275 (150W) and 2280 (300W) electronic loads offer high input voltage (up to 360V) and precise measurement resolutions (1mV/1mA/1mΩ/1mW). They are indispensable tools for laboratory, field testing, and training environments due to their extensive functions, including resistance testing, short-circuit testing, battery testing, user-defined test sequences, and PC software evaluation.

Key Features:

• User-friendly operation with keypad and rotary knob
• High-contrast LCD display
• Basic modes: Constant Voltage (CV), Constant Current (CC), Constant Resistance (CR), Constant Power (CP)
• Short-circuit, battery, and dynamic testing capabilities
• User-defined test sequences
• Protection functions: Overvoltage, overcurrent, overpower, overheat, reverse polarity
• High-precision remote sensing input
• Temperature-controlled fan
• Keypad lock function
• RS-232 interface with USB adapter for PC software
• Multi-unit support via RS-485

Accessories Included:

• User Manual
• Mains Cable
• USB to COM Adapter
• CD-ROM

Technical Specifications

Main Data

Measurement Precision

Operating Environment

• Temperature: 0°C ~ 40°C
• Relative Humidity: ≤ 90%RH
• Air Pressure: 86 ~ 104 Pa

Unit Front and Rear

Front Panel

The front panel features a high-contrast LCD display, a rotary knob for adjustments, input terminals (+/-), a keypad for operation, and a power ON/OFF button.

Rear Panel

The rear panel includes ventilation openings, a 110V/220V AC selector switch, remote sensing and trigger inputs (DB-9 connector), an RS-232 interface, and an IEC power socket with a fuse holder.

Keypad Layout

The keypad includes numeric keys (0-9, .), mode selection keys (I-SET, V-SET, P-SET, R-SET), menu navigation keys (ESC, ENT, ▲, ▼, SHIFT), and function keys (MENU, LOCAL, TRIG, ON/OFF).

Display Information

The display shows key parameters such as current (Is), voltage (V), and power (W). Status indicators like 'OFF' or 'RUN' are also displayed.

Menu Operation

General

The menu system allows access to all operating modes and unit settings. Navigate using the arrow keys or the rotary knob. Pressing [ENT] selects an item, and [ESC] exits the current menu.

Menu Structure

The menu is organized into main categories such as 'System Configuration' and 'Load Setting'. Submenus allow for detailed adjustments of parameters like communication settings, trigger sources, and load configurations.

System Configuration

• Power-on Call: Configures automatic loading of preset files upon startup.
• Key Beep: Enables or disables audible feedback for key presses.
• Key Lock: Activates or deactivates the keypad.
• Knob Lock: Enables or disables the rotary knob.
• Trigger Source: Selects between Manual, External, or BUS triggers for dynamic and list tests.
• Communication Mode: Configures RS232C communication settings, including separator and multiplier modes.
• Local Address: Assigns a unique address to the unit for multi-unit communication.
• Baud Rate: Sets the communication speed for the RS232C interface.
• Restore Settings: Resets the unit to factory default settings.
• Restore Cal Data: Performs auto-calibration.

Load Setting

This submenu contains parameters for configuring the electronic load's behavior, offering flexibility for various applications.

• Max. Current: Sets the maximum current limit. Exceeding this limit triggers an audible alarm and 'OC' message, potentially shutting down the unit.
• Max. Voltage: Sets the maximum voltage limit. Exceeding this limit triggers an audible alarm and 'Exceed Voltage!!!' message, shutting down the unit.
• Max. Power: Sets the maximum power limit. Exceeding this limit triggers an audible alarm and 'OP' message, potentially shutting down the unit.
• Turn-on Voltage: Sets a minimum voltage threshold for the load to activate.
• Turn-off Voltage: Sets a voltage threshold below which the load will shut down.
• Auto Off: Automatically disables the load after a specified time interval.

Battery Test Set

This mode allows for battery discharge testing to determine discharge time and capacity. Users can set the discharge current and minimum voltage.

Tran Test Set (Dynamic Test)

This mode enables dynamic load testing by switching between two levels (A and B) with specified durations (Width A, Width B). It supports continuous, pulse, and trigger modes.

User-Defined Instruction List (List Test Set)

Allows users to create custom test sequences with up to 15 steps. Each step can be configured with load mode, level, delay time, and comparison parameters. Sequences can be set to repeat automatically or be triggered externally.

Save File / Recall File

Users can save current load settings as files (0-9) for later recall. The unit indicates whether a file has been saved ('Y') or not ('N').

Operation Modes

6.1 Constant Current (CC) Mode

In CC mode, the load maintains a constant current regardless of input voltage variations. The current can be set using the keypad or rotary knob.

6.2 Constant Voltage (CV) Mode

In CV mode, the load adjusts its internal resistance to maintain a constant voltage across its terminals. This mode requires the input voltage to be at or above the set voltage.

6.3 Constant Power (CP) Mode

In CP mode, the load maintains a constant power output. As voltage changes, the current is adjusted accordingly to keep the power level constant.

6.4 Constant Resistance (CR) Mode

In CR mode, the load maintains a constant resistance. The absorbed current varies proportionally with the applied voltage.

6.5 Battery Test Mode

This mode simulates battery discharge by drawing a constant current, causing the battery voltage to drop over time to a predetermined level. It measures discharge time and capacity.

6.6 Short-Circuit Test Mode

This mode simulates a short circuit at the input terminals.

6.7 Dynamic Test Mode

This mode allows switching the load between two voltage or current levels to evaluate the transient behavior of a source. It supports continuous, pulse, and trigger modes.

6.8 Fault Protection

The unit includes protection against overvoltage, overcurrent, overpower, reverse polarity, and overheating. Specific messages and actions are displayed upon activation of these protections.

Appendices

Appendix A: Remote Sensing and External Trigger Interface

The DB-9 connector on the rear panel provides remote sensing input for accurate voltage measurements and external trigger functionality for dynamic and list tests. Pin assignments are detailed for trigger (Pins 1, 5) and voltage sensing (Pins 6, 9).

Appendix B: PC Software

The included Windows software allows for remote control of the electronic load, data logging, and analysis. It supports RS-232 communication and requires installation of the PL2303 driver for USB connection. The software features tabs for Main settings, Battery Test, List Test, Instructions, and About. Data is saved to 'db.mdb' and can be exported for further analysis.

Safety Instructions

• Ensure the unit is connected to a properly grounded outlet.
• Verify that the mains voltage matches the unit's setting.
• Do not operate the unit in wet or humid conditions.
• Avoid inserting metallic objects into ventilation slots.
• Use only 4mm safety test leads.
• Do not touch test lead tips.
• Do not expose the unit to extreme temperatures or direct sunlight.
• Perform measurements with dry clothing and preferably rubber-soled shoes or on an insulating mat.
• Keep hot soldering irons away from the unit.
• Allow the unit to stabilize to ambient temperature before operation.
• Clean the unit with a damp cloth and mild detergent; avoid abrasive cleaners.
• Only qualified personnel should perform repairs or maintenance.
• Do not modify the unit.
• Keep measuring instruments out of reach of children.