The picture shows the B628 circuit, which is a 5V boost to 12V, 5V is provided from 7805, but after boosting, when there is no load, 7805 will heat up, and it will heat up quickly with load, and it can barely work for a while, after boosting The load current is 100mA, and the power is about 12W. Why does 7805 get fever? Can it be solved?
Joanne Posted on December 24, 2020
7805 belongs to LDO, with low conversion efficiency of only 50-70%. When you connect a load, the power consumption above 7805 has reached at least 5W. This heating is very serious. Personally, I feel that it can be replaced with a switching power supply. How old is your VCC?
Kenyon Posted on December 24, 2020
The boost chip does not have an input voltage range, and the output voltage is also automatically regulated, how can it add 7805, if VCC is too high, it will increase the power consumption of 7805, so it will generate heat.
Elmer Posted on December 24, 2020
The input voltage is high or the load is too large
