TH8204 Programmable DC Electronic Load

TH8200 series programmable DC electronic load is a high performance, full-featured DC electronic load independently developed and manufactured by Tonghui.

TH8200 series products use dual-core (ARM + DSP) automatic control hardware circuit architecture, making the system run more stable; complete hardware protection circuit function (OVP, OCP, OPP, OHP, REV, UVP) on the implementation of the instrument and the object to be measured to implement the comprehensive protection, eliminating the user's worries.

Adopt high-speed, safe and reliable 16-bit sampling chip to ensure sampling accuracy and resolution, single sampling can be synchronized to refresh the voltage and current values; 100kHz real sampling rate, high measurement accuracy, strong anti-interference ability, and can display transient loading current waveform.

The maximum load current change rate is up to 24A/μs (TH8204), and the minimum setting resolution is 10μA (TH8201), making it possible to cope with a wide range of power supply and current sensor tests that require high-speed current changes.

The load has a programmable soft-start feature with a Linux operating system that allows for an unlimited number of setup storage files and improves compatibility with USB storage devices.

The humanized interactive design of the front panel of the instrument allows users to set up various operations conveniently and quickly, and provides a wealth of wired and wireless communication interfaces to meet the user's communication and system connection needs.

A. Load operating mode

Conventional mode (4 types)

CC constant current mode

An electronic load always draws a constant current, regardless of whether the voltage changes.

CR constant resistance mode

An electronic load is equivalent to a constant resistance, and the load changes current linearly with voltage.

CV constant voltage mode

The electronic load controls the voltage output from the power supply by adjusting the pull current according to the set voltage value.

CP constant power mode

An electronic load is equivalent to a constant resistance, and the load changes current linearly with voltage.

Advanced modes (12)

DYN Dynamic Load Mode

A dynamic test frequency of up to 50kHz can be used to test the dynamic characteristics of the power supply over a wide bandwidth, with two current levels that can be set, the duration of each of the two current levels, the rising slope, the falling slope, and the number of repetitions. This function can be used to test the instantaneous high current tolerance of D/D converters and batteries.

SWP dynamic frequency sweep mode

The electronic load provides a programmable dynamic frequency sweep to invert the frequency to find the worst case voltage of the object to be measured. Dynamic Frequency Sweep requires the setting of two current levels, start frequency, end frequency, step frequency, duration, rise slope, and fall slope. During operation, the electronic load will pull current at the set frequency for the set duration. Frequencies up to 50kHz are used to capture the worst case Vp+, Vp- and corresponding Fp+, Fp- of the power supply under test.

CR-LED Analog LED Test Mode

By setting the on-state voltage and resistance of the light-emitting diode, it can realistically simulate the actual load characteristics of the LED, avoiding the oscillations generated by the unstable voltage and current under the conventional constant resistance mode (CR), and thus detecting the real load conditions of the LED power supply.

ARB Arbitrary IV Characterization Model

In ARB mode, 3-100 I-V characteristic points can be set to form an arbitrary I-V characteristic curve. Linear interpolation is used between the two points. This mode can be used to simulate diodes, etc.

BATT Battery Test Mode

Load test battery performance, discharge conditions support CC, CR and CP three ways, by setting voltage, time, current capacity or power capacity of four conditions to let the electronic load to stop pulling load, to ensure that the battery will not be over-discharged and damaged.

Load Effect Test

The load will be carried under low quasi-pull current (Imin), high quasi-pull current (Imax) and normal operating current (Inormal) for a preset period of time (Delay), and then the voltage values under different loads will be recorded to measure and display the Load Adjustment Ratio (Regulation), ΔV, and Power Supply Internal Resistance (Rs) of the power supply under test.

Typical waveform loading function

Editable periodic current signal for pull-loading

Waveform types: sine, triangle, square, trapezoidal, pre-sawtooth, post-sawtooth

Adjustable parameters: amplitude, period, etc.

This function can be used to simulate the power-on of capacitive loads, to simulate the pull-load condition of nonlinear loads, and to simulate the carry-load of automobile generators.

TIME time measurement mode

Measures the time from the start of the trigger condition to the cut-off of the trigger condition in the range of 0s to 100000s. Can be applied to battery charging and discharging tests and other similar applications.

MPPT Maximum Power Point Tracking Test Mode

Based on the DSP algorithm, find out the maximum power provided by the power supply and the corresponding voltage and current values.

OVPT overvoltage protection test mode

The load captures the peak and falling edge of the input voltage and triggers at the preset level (Vtrig) at the falling edge moment, then this voltage peak is the overvoltage protection point of the power supply under test, and the time interval between the peak moment and the triggering moment is the OVP response time of the power supply under test (Tovp), and the accuracy of Tovp measurement is 2us.

OCPT Overcurrent Protection Test Mode

The electronic load pulls a step-up current to test whether the output voltage of the power supply is lower than the trigger voltage under overload conditions, and then determine whether the output protection function of the power supply is normal.

OPPT Over Power Protection Test Mode

The electronic load pulls the load step-up power to test whether the output voltage of the power supply is lower than the trigger voltage under overload conditions, and then determine whether the output protection function of the power supply is normal.

MPPT Maximum Power Point Tracking Test Mode

Based on the DSP algorithm, find out the maximum power provided by the power supply and the corresponding voltage and current values.

LIST List Test Mode

The LIST mode can accurately complete complex arbitrary current change patterns at high speeds, accomplishing precision testing of multiple quasi-positional current carry loads. Multiple complex sequences are generated by editing the pull-load value, duration, slope, and repetition times for each step to meet complex testing needs.

It is mainly applied to simulate battery discharge pull current, laptop pull current, electric vehicle pull current, and dynamic current above two current levels.

AUTO automatic test mode

The AUTO mode can accurately simulate the automatic test process of the production line and complete the multi-step precision test, which can help customers to save cost greatly. Different modes can be set for each step, and by editing the pull-load value, duration, rising slope, falling slope, and the upper and lower limits of current, voltage and power for each step, you can judge whether each step is qualified or not.

Typical circuit model simulation loading function

The user selects a circuit model and customizes the component parameters, and the load simulates the V/I characteristics of that circuit

Provides six common impedance circuits

Simulates capacitive load turn-on, simulates pull-load condition of nonlinear load, and simulates automotive generator with load.

B. Programmable rate of change of loading current

The user can set the rate of change during current loading according to the application. If the rate is set, the rate will take effect in the following cases.

◎ When changing the set value to change the current value (including various advanced functions).

◎ When there is a change due to the loading current value.

C. Programmable soft start function

The soft start function can be used to set the rise time of the load current. The start-up time is continuously adjustable between 10μs and 500ms.

This function can be used to prevent the output of the DUT from becoming unstable due to a sharp rise in load current, or to avoid a delayed start of the power supply due to overcurrent protection.

D. Digitizer function (digitized)

According to the set sampling rate (100Hz-100kHz) to collect a set number of points of voltage and current values, and in the form of curves displayed on the screen, can also be uploaded to the host computer for data processing. It is mainly used to capture voltage and current transient signals.

E. Short-circuit function

Independent short-circuit test function supports short-circuit test in any function mode, realizing seamless connection with other functions. When the instrument enters the short-circuit test, the instrument is loaded at the maximum current of the current range.

F.Parallel function

There are two ways to parallelize a machine:

◎ Master-Slave Mode

One of the units is used as the master and up to 4 units of the same model are connected in parallel as slaves. The panel of the master can control and display the whole system. The corresponding number of parallel operation cables is required.

◎ Host + power amplifier mode

With a single power of 1kW or more load as the host, you can connect 4 power amplifiers in parallel, the panel of the host can control and display all the system.