Method for presetting up low resistor on circuit board and high-current detector for electric vehicle

Abstract

A method for pre-arranging low resistor on circuit board features that copper foil is reserved on the circuit board and the area of copper foil is determined according to the resistance value per squar centimeter. The microresistor has long strip shape with selectively modified bridge in order to regulate resistor value. Said low resistor can be used to measure the current of electric vehicle with power loss for test. Its advantages are stable temp coefficient and high temp radiation.

Description

technical field [0001] The invention is aimed at the innovation of low-resistance manufacturing, especially a low-resistance manufacturing method that is directly formed on a circuit board, is cheap and easy to manufacture, and can obtain a very small and precise temperature coefficient stable resistance value. Background technique [0002] The earth's resources are limited and combustion will cause air pollution. Many traditional fuel-based power supply methods have gradually changed to smoke-free and environmentally friendly electric power supply methods. For example, electric vehicles that are gradually being developed and used in daily production are recently. An obvious example is that this kind of personal vehicle is mainly powered by electric drive, but there are limited places for charging, and its power storage cannot be as simple as the existing fuel filling method, and the charging time is longer The inventory can not be identified by the appearance at a glance, s...

AI Technical Summary

Problems solved by technology

[0002] The earth's resources are limited and combustion will produce air pollution. Many traditional fuel-based power supply methods have gradually changed to smoke-free and environmentally friendly electric power supply methods. For example, electric vehicles that are gradually being developed and used in daily production are recently. The obvious example is that this kind of personal vehicle is mainly powered by electric drive, but there are limited places for charging, and its power storage cannot be as simple as the existing fuel filling method, and the charging time is longer The inventory cannot be identified by the appearance at a glance, so the detection results of the relevant electrical measuring equipment are an important basis for the user to judge whether the working equipment can operate normally. In addition, in order to effectively improve the driving power and mileage of the car, this The power saving of basic equipment can effectively improve the driving power and mileage of the car. The power saving of this basic equipment should be highly demanded to avoid unnecessary virtual power loss. Only in the detection of large current in the electronic circuit is a A major issue, taking the current detection structure of the existing electric vehicle as an example, figure 1 achieved with a CT or current sensor as shown, figure 2 It is obtained by voltage division of micro-resistors in the form of PWM, and the cost of the former is as high as several hundred yuan, which is very unfavorable for product market competition. Assembling is the same as the former, there is still the trouble of plug-in welding. In addition, it has the following disadvantages as a large current detection:

[0003] 1. The size of the existing micro-resistance itself has a certain limit, and it cannot be made too small at will, and this will cause unnecessary loss in the use of high-current power. For example, taking an electric car as an example, the motor current is about 40 to 40 About 60 amps, assuming that a 0.01 ohm micro-resistor is used today, the light will be 0.01*60 2 = 36W power, which is undoubtedly an excessive waste for electric vehicles with limited power storage

[0004] 2. The existing unit type micro-resistors are long strips such as image 3 As shown, the temperature coefficient is very unstable, especially when used to measure large currents, errors often occur due to temperature changes, which affect the accuracy of detection

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