DC Regulator Power Circuit With Short Circuit Protection

Published:2011/8/23 23:40:00 Author:Robert | Keyword: DC, Regulator, Power, Short Circuit, Protection | From:SeekIC

The picture shows the DC regulator power with short circuit protection. The circuit uses the bistable circuit, which composed of VT7 and VT8, as the protection circuit. The R1 is the detecting resistance for the short circuit signal or over load signal. Its resistance value is very small. When it is working normally, there is low voltage drop on the R1, the VT8 is conducted and VT7 is disconnected, The VT3 is also disconnected. The protection circuit would not have action. When there is short circuit or overload, the R1's voltage would increase rapidly to make the VT8's base voltage increased to be disconnected. The VT8's collector voltage reduces and it would add onto the VT7's base electrode through the R15 and R16's voltage divider to make the VT7 conducted. So the VT7's collector voltage would increase to make the VD3 conducted. This would add the short circuit signal or overload signal to the VT3's base electrode to make its voltage increase to be disconnected. Thus it would protect the adjustment tube.



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