一、Now I need to make a scheme to measure the residual current. To solve the problem of leak current detection of charging gun, the current value needed to be detected is as follows:
1. AC breaking value, DC breaking value, reverse DC breaking value, sudden appearance of 15mA, 30mA, 60mA, 100mA, 200mA, 5A, 10A, 20A AC leakage current;
2. Sudden 3mA, 6mA, 60mA, 300mA DC leakage current, self-test function。
二、I do the leakage detection. I want to use the method in the figure below. Based on the principle of the fluxgate, when the leakage current of the primary conductor in the figure is generated, the induction coil transmits the signal to the chip, and Vout outputs a high. Level. This output can be in two ways: the first is that there is leakage current, Vout will output a fixed high level; the second is that the output level of Vout is linear with the magnitude of the leakage current.
三、From the point of view of parameter index, machining and fixing, etc.Can I use DRV421?
