• Categories:Technical Support
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• Time of issue:2013-05-27
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(Summary description)Constant current and constant voltage control module

(1) Frequently asked questions about the first use of the module

A simple function test can be performed before the module is used. It can test the constant current function and the constant voltage function, but it is more convenient to choose the constant voltage function test. The following points are common problems when using for the first time, which may be instructive for you.

①When adjusting the given signal, the module has no current or voltage output, but the given signal and the external ±12V power supply are normal.

Handle: You need to reset the module.

②In constant voltage applications, the output voltage measured with a voltmeter is not accurate or continuous.

Reason: Your load is too small, change a load greater than 100w.

③In constant current application, if the given signal is small, the module will output full voltage.

Treatment: You need to work at a higher current, such as 20A.

④The constant current accuracy or constant voltage accuracy of the module cannot reach the specified index.

Reason: The power supply index cannot meet the requirements or the given signal is unstable.

⑤Can the constant current and constant voltage functions be used at the same time?

Answer: No, it can only work alone in a constant current or constant voltage mode, or switch in order.

⑥Can the module reach the maximum nominal current value under any output voltage?

Answer: No, the nominal current of the module is the maximum output current at full voltage output. The specific output current also depends on the output voltage and stability accuracy.

⑦How to choose the best working interval of the module?

Answer: Module application is best when the nominal value is 20%-60%; when it is less than 20% or greater than 70%, the effect is poor.

⑧How to discharge the battery when charging the battery?

Method 1: Adjust the positive and negative output polarity of the module to be opposite to that during charging.

Method 2: Connect the positive pole of the module to an inductor. The polarity of the module is the same as that during charging. First adjust the module voltage to be higher than the battery pack, then slowly reduce the module output voltage to the battery discharge voltage value, and use the inverter method to complete the battery discharge . This method is suitable for professional users.

⑨The index drops when the module is used for inductive load.

Reason: The voltage and current sensor processing circuit of the module may process the induced signal voltage differently from the ordinary instrument. The thyristor will produce reverse spikes during commutation, and the module processing circuit will suppress the spikes; while ordinary instruments will handle the spikes as usual, so it is a normal phenomenon, not a drop in indicators.

⑩How to find the radiator temperature test point?

Method: The test point should be close to the center of the module and close to the surface of the radiator of the module housing.

(2) Current selection rule

①Selection of module current

The nominal current of the module is the maximum current allowed to flow through the module during normal operation. Considering the poor resistance to current impact of the thyristor, it is recommended that you leave a margin when selecting the module.

Resistive load: The nominal current of the module should be 2 times of the rated current of the load. Inductive load: The nominal current of the module should be 3 times the rated current of the load:

② Conduction angle requirements:

In the non-sine wave state, the current value measured by an ordinary instrument is not an effective value. The smaller current value displayed by the instrument may exceed the rated value of the module by several times. Therefore, the module is required to work at a larger conduction angle as much as possible ( Above 100 degrees). The module outputs a larger current under a smaller conduction angle (that is, the module's high input voltage, low output voltage), which will cause the module to heat up and burn.