A multi-channel power supply parallel current sharing device and method for module detection

Abstract

The invention discloses a parallel current sharing device for multiple channels of power supplies for module detection. The device comprises multiple channels of power supplies, which are all providedwith first ports for supplying power to a load through a transmission line, wherein any one channel of power supply is used as a reference power supply, the non-reference power supplies are respectively provided with second ports of another fixed voltage and external circuits connected to the second ports, and the external circuits automatically adjust voltage values of the non-reference power supplies output to the transmission lines thereof by using a current conservation principle at the second ports, so that the voltage values of the non-reference power supplies output to the transmissionlines and the voltage value of the reference power supply output to the transmission line are automatically equal. The implementation manner is simple and effective ensures the stability and reliability of the parallel current sharing device for multiple channels of power supplies for module detection.

Description

technical field [0001] The invention belongs to the field of module detection, and in particular relates to a multi-channel power supply parallel current sharing device and method for module detection. Background technique [0002] Liquid crystal display is a flat ultra-thin display device composed of a certain number of color or black and white pixels. It is placed in front of the light source or reflective surface. If an electric field is applied to the liquid crystal, its molecular arrangement will be changed. At this time, if it is equipped with a polarizer , it has the function of preventing light from passing through, that is, light can pass through smoothly when no electric field is applied. If it is combined with a color filter and the voltage applied to the liquid crystal is changed, the amount of light transmitted by a certain color can be changed. It can be vividly said that changing the voltage across the liquid crystal can change its light transmittance. Therefo...

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Problems solved by technology

[0003] With the development of the LCD panel display industry, the size of the LCD TV LCD panel is getting larger and larger, and the load voltage or current requirements for the test power supply equipment are also higher. Since the same production line can realize the production of LCD TV LCD panels of different sizes, for For module testing equipment, it is necessary for the same device to support multiple power outputs. For example, when producing small-sized products, it can provide several independent power outputs, and when producing large-sized products, it can provide one power output in parallel. The equipment needs to provide several independent power supplies, and the cost of the detection equipment also increases accordingly. At the same time, the detection equipment is directly connected in parallel without performing parallel current sharing processing, and one power supply may be overloaded and the other power supply may be lightly loaded, or even overloaded. The phenomenon that it cannot be used due to protection affects the stability and reliability of the power supply, thus reducing the service life of the detection equipment

[0004] For the existing parallel current-sharing detection equipment, the output voltage and current of each power supply are generally sampled, and the sampling results are sent to the programmable logic device, and the output current is compared by the programmable logic device. The calculation result and the output current of the power supply are adjusted through the clamping circuit. However, the circuit implementation of this method is too complicated, and the high requirements for the sampling accuracy of the sampling circuit and the accuracy of the clamping circuit make the cost of the entire device increase. At the same time, it also needs Programmable logic devices are used for software development and debugging, which makes the development cycle of equipment longer

In addition, in order to ensure that the output voltage at the load end is up to standard, the detection equipment generally adopts the average current method using the current detection resistor, that is, a resistor for current detection is added to the test circuit connection. However, when the load current is large in this method, the current detection resistor There will be a large heat loss on the circuit, which will affect the reliability of the circuit. At the same time, a large voltage drop will also be generated at both ends of the current-sensing resistor, which will cause the voltage output from the detection device to the load terminal to be substandard.

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