I am a beginner, switch power supply has been no contact before switching power supply design, but this time a project given the cost of the board and the installation area have to consider their own design switching power supply, so saw a lot of data and according to the design engineer before copy a circuit schematic diagram, I now do is ready, the whole project and the client side is approved on function, project control panel below:

Project requirements are two voltage 110 v and 220 v input, 15 w output 5 v 1 a current (voltage),


problem is now in the actual output of more than 6 w TNY277 chips and next to the transformer and the transformer components surface is very hot, feel very hot, anywhere feel the appearance of fire, and especially TNY277 chip at the time of 8 w output that hot to finger can't meet with

As shown in figure electronic load test
the condition of the


Below is the artwork of switch power supply circuit and the design parameters of transformer:



Transformer design parameter



Please predecessors your advice, I should test the parameters of modified components parameters or modify the parameters of the transformer, thank you very much,

CodePudding user response:

Problem now is in the actual output of more than 6 w TNY277 chips and next to the transformer and the transformer components surface is very hot, feel very hot, anywhere feel the appearance of fire, and especially TNY277 chip at the time of 8 w output that hot to fingers couldn't meet,

CodePudding user response:

High temperature because there is a "chip inside, when the voltage is too high, the power consumption is larger,
Can reduce the input voltage to AC90V try, if the temperature is down, we inference is correct,
Solution, refer to the application of chip circuit
BP/M pins should need auxiliary coil power supply

CodePudding user response:

Ask to amo BBS, here...

CodePudding user response:

Transformer without magnetic gap?
Power transformer is too small?