Flyback LED Driver Help

[Benjman]

Hello Everyone

i'm currently working with a Flyback LED driver 40W output power.

i have some question regarding the Flyback Transformer.

1.) i don't quite understand what is a flyback Voltage / Flyback Reflected Voltage i want to know how to properly calculate that voltage,
i have read some white notes it is only assume around 77-100V i just want to know how did they arrived with kind of assumption.

2.) my transformer heats up to 60C what could have causing these heat? im using EFD25 Core, i want to lessen the heat dissipation any advice?

3.) same as for the Mosfet i'm also having heat problem i also want to lessen the heat i'm using a 7N60 Mosfet.

Thanks in advance guys.

 

[schmitt trigger]

"my transformer heats up to 60C what could have causing these heat? im using EFD25 Core, i want to lessen the heat dissipation any advice?"

If the core is heating up, you require to lower the flux density. Add more turns, if there is available window area, or increase the core size to increase the magnetic cross section. Or use a higher performance ferrite.
If the wire itself is heating up, you require a larger copper cross section, or litz wire if the frequency is high enough to cause skin effects.

 

[Benjman]

"my transformer heats up to 60C what could have causing these heat? im using EFD25 Core, i want to lessen the heat dissipation any advice?"

If the core is heating up, you require to lower the flux density. Add more turns, if there is available window area, or increase the core size to increase the magnetic cross section. Or use a higher performance ferrite.
If the wire itself is heating up, you require a larger copper cross section, or litz wire if the frequency is high enough to cause skin effects.

Thank you sir, very helpful