The PLZ-5W Series high performance electronic load is the successor to the highly respected PLZ-4W series, whilst still retaining the same high specification and build quality. Advances include a high visibility color display and low voltage operation from a minimum of 0.25 V to a maximum of 150 V. Programmable profiles of voltage/current can be applied (using the new ARB function, as used in LED/solar testing) in addition to the inherited 6 modes of operation: Constant Current, Constant Resistance, Constant Voltage, Constant Power, Constant Current + Constant Voltage, Constant Resistance + Constant Voltage. Equipped with a high-speed response feature boasting a maximum slew rate of 60 A/μs (PLZ1205W) and a minimum setting resolution of 10 μA (PLZ205W). Additional features of the PLZ-5W series include: Soft-start function, variable slew rate, selectable response (CV/CR mode), switching function, ABC preset memory, 20 user-defined set-up configurations, and a sequence operation function. The advanced high-speed response makes the PLZ-5W ideal for the development and testing of today’s modern power supplies that require variable high-speed current changes. This advantage extends to the testing of current clamps/transducers. The PLZ-5W Series is available in 4 standard models which can be incrementally extended by adding additional booster units (PLZ2405W) to achieve a maximum of 10.8 kW / 2160 A DC electronic load.
|Constant current mode
|Constant voltage mode
|Range H (A)
|Range M (A)
|Range L (A)
|Range H (V)
|Range L (V)
|Range H (mV)
|Range L (mV)
|0.25 to 150
|0 to 42
|0 to 4.2
|0 to 0.42
|0 to 157.5
|0 to 15.75
|0 to 84
|0 to 8.4
|0 to 0.84
|0 to 252
|0 to 25.2
|0 to 2.52
|Constant resistance mode
|Constant power mode
|Range H (S)
|Range M (S)
|Range L (mS)
|Range H (W)
|Range M (W)
|Range L (W)
|42 to 0
|4.2 to 0
|420 to 0
|0 to 210
|0 to 21
|0 to 2.1
|84 to 0
|8.4 to 0
|840 to 0
|0 to 420
|0 to 42
|0 to 4.2
|252 to 0
|25.2 to 0
|2520 to 0
|0 to 1260
|0 to 126
|0 to 12.6
Color liquid crystal display (LCD)
High visibility color display. The voltage, current, power, current capacity (Ah) and power capacity (Wh) values are conveniently displayed.
Maximum slew rate of 60 A/μs
Achieving a rise time of 4 μs to reach the rated current of the electronic load. Power supply evaluation demands a fast transient response which the PLZ-5W series achieves with ease.
High speed voltage tracking characteristics
High speed voltage tracking characteristic in CR mode is perfect for applications such as startup tests for power supplies.
The following five operation modes are available on the PLZ-5W. These can be selected when the load is in the off state.
|Constant current (CC) mode
|A current value is specified and the current is kept constant even when the voltage changes.
|Constant resistance (CR) mode
|A conductance value is specified and the PLZ-5W sinks current proportional to the voltage variation.
|Constant voltage (CV) mode
|A voltage is specified and the PLZ-5W sinks current so that the voltage at the load input end of the PLZ-5W is constant.
|Constant power (CP) mode
|A voltage is specified and the PLZ-5W sinks current so that the power consumed inside the electronic load is constant.
|Arbitrary I-V characteristics (ARB) mode
|The desired load characteristics can be set by specifying multiple arbitrary voltage values and current values as I-V characteristics.
Adjustable slew rate
The speed of change can be set when the current is changed.The slew rate setting will function in the following instances.
- When the setting is changed to vary the current value (including the switching function).
- When the current value is changed using external control in constant current (CC) mode.
- When the current value is changed while the load is on.
The slew rate is set according to the current range as an amount of current change per unit of time. Moreover, a common value is set for the rise and fall speeds. In CC mode and ARB mode, the slew rate can be set regardless of whether the load is on or off.
High precision and high resolution
The built-in three-range configuration provides wide dynamic range and high precision.
Load on/off operation
The following load on/off settings are available in addition to standard operations that can be carefully adjusted to fit the needs of any test environment.
- Start with “load on” when power is turned on
- Display elapsed “load on” time
- Auto “load off” when time limit is reached
- Control “load on/off” with external controls such as relays
Arbitrary I-V characteristics (ARB) mode
In ARB mode arbitrary I-V characteristics can be set by entering multiple I-V points (voltage and current value set points). 3 to 100 points can be registered and the spaces between all points are automatically linearly interpolated. This mode can be used for the simulation of LED drivers and other DUT’s with non-linear characteristics.[P8]
When the short function is activated, the maximum current value will be set if in CC mode, and the minimum voltage value will be set if in CR mode. The relay contact (30 Vdc/1 A) of the EXT CONT connector closes, and the load imput terminals can then be shorted by driving an external high-current relay.
Switching mode can be performed at up to kHz while in CC and CR modes. The switching setting parameters such as switching level, frequency, and duty factor can be changed at any time, even while the load is on.
- Operation mode: CC and CR
- Frequency setting range: 1 Hz to 100 kHz
- Frequency setting resolution
1Hz to 10Hz 0.1Hz 11Hz to 100Hz 1Hz 110Hz to 1kHz 10Hz 1.1kHz to 10kHz 0.1kHz 10kHz to 100kHz 20kHz,50kHz,100kHz
- Frequency setting accuracy: ±(0.5 % of set)
- Duty factor, steps
1 Hz to 10 Hz 5.0% to 95.0%, in steps of 0.1% 11 Hz to 100 Hz 110 Hz to 1000 Hz 1.1 kHz to 10.0 kHz 5.0% to 95.0%, in steps of 1% 10 kHz ～100 kHz 10% to 90%, in steps of 10%
The minimum time interval for setting the duty factor is 5 μs.
Soft start function
The soft start feature controls the rise time of the load current. The soft start feature can be activated when the following conditions are met.
- The rise time of the soft start has been set.
- “Load on” while in CC Mode.
- Soft start input settings start from zero input and end equal to or above the minimum operating conditions.
This function can be used if the output of the DUT becomes unstable when the load current rises sharply, or when the operator wishes to delay the current change on startup to prevent the DUT’s overcurrent protection circuit from being activated.
The operator can execute a long sequence of predetermined values with the sequence function. A sequence consists of programs and steps. A program is a collection of steps, which are executed in order, one by one, starting from step 1. The program is considered complete after the last step in the program is executed.
|Current, conductance, voltage, power. The values that can be set depend on the current operation mode.
|Step execution time
|0.000025s to 3600000s
|Transition method of the current value
|Step or Ramp
|Number of loops of program
|1 to 100000 repetitions, or infinite repetitions.
|Sequence editing / execution / stop method
|Front panel operation or remote operation via RS232C / LAN / USB.
|Load on/off control, Slew Rate, CV mode addition, Trigger signal setting, trigger signal output, Specifies the value at which a protection function (OCP, OPP, UVP) is activated.
The operator can use the TALink (Transient Acquire Link) trigger to synchronize the PLZ-5W with steps of a sequence and enable data logging. Logged data can then be acessed via digital communication with the PLZ-5W.
Remote sensing function
With remote sensing, the voltage measurement point can be changed from the load input terminal to the DUT sensing point. By connecting the sensing leads to the DUT, the effects of voltage drops caused by resistance in the load cables can be reduced and the load current stabilized. To activate remote sensing, connect the sensing cables to the sensing terminals of the PLZ-5W at the DUT end, and enable the remote sensing function.* Possible remote sensing compensation voltage : approx. 7 V (Total potential difference between the input terminals and sensing terminals)
Auto load off timer
The auto load off timer automatically turns off the load after a specific amount of time elapses from the discharge of the DUT. The integrated power and current is measured immediately after the load is turned off, ideal for battery discharge tests.
The following synchronization features are available when simply connecting the PLZ-5W with other equipment using a communication cable.
- Synchronizing load on/off among multiple pieces of equipment
- Synchronizing measurements (remote control)
- Synchronizing the start time and resume time for sequences across multiple units
Different PLZ-5W models can be connected (Ex: PLZ205W and PLZ1205W). Synchronization is also available during parallel operation.
The setup memory can store up to 20 sets of the settings listed below.
- Operation mode
- Load settings (current, conductance, voltage, power)
- Current range setting
- Voltage range setting
- Slew rate
- Switching level (current value/conductance value, or percentage)
- Switching interval (frequency/time of one cycle and duty cycle/ operating time on the high side.)
- Alarm detection point
- Content of ABC preset memories
ABC preset memory
Three setting values can be stored in preset memory slots A, B, and C. The stored values can be recalled freely at any time even when the load is on. In CC+CV and CR+CV modes, constant current and constant voltage values, as well as constant resistance and constant voltage values can be recalled and saved, respectively.
Diverse protections, other functions
Overcurrent protection (OCP), Overpower protection (OPP), Overvoltage detection(OVP), Undervoltage protection (UVP), Overheat detection(OTP), Reverse-connection detection(REV), Alarm input detection, Configuration setting, USB Keyboard Compliant
Current sensor evaluation (example)
Accurate current sensor evaluation possible when combined with a high-precision CC DC power supply. Additionally, 3-level range settings allow you to.
Power supply impedance measurement (example)
Arbitrary I-V characteristics (ARB) mode
In ARB mode arbitrary I-V characteristics can be set by entering multiple I-V points (voltage and current value set points). 3 to 100 points can be registered and the spaces between all points are automatically linearly interpolated. This mode can be used for the simulation of LED drivers and other DUT’s with non-linear characteristics.
Impedance measurement of the power supply (example)
When using the PLZ-5W
Measure power supply impedance by configuring a system using the PLZ-5W, a function generator, and a digital multimeter.
When using the PLZ-5WZ
A function generator is not necessary.
Fuse rupture test (example)
For fuse rupture tests, DC power supplies with high-speed CC current control is absolutely vital. Although it is normaly quite difficult to achieve such high-speed control with only a DC power supply, the addition of a PLZ-5W electronic load makes high speed current control possible. With the PLZ-5W, fuse rupture tests that adhere to standards such as the JASO D612 are made possible. These tests include voltage drop tests, transient current cut-off tests, rupture time tests, step energization tests, and breaking capacity tests.
Battery evaluation test (example)
Although high-speed operation cannot be achieved using only the PAT-T high-capacity switching power supply, the fast-response unipolar power supply system can be suplemented by connecting with the PLZ-5W series electronic load in series and parallel. This makes it possible to flow current while synchronizing the charge and discharge current patterns for a battery at high speeds. Furthermore, the additional features of the PLZ-5WZ allow for seamless measurement of battery imedance during evaluation.