510 ohm 1% 1/4 Watt Resistor (Box of 5000) - MFR 33K It can be used either

It can be used either as a voltage mode or current mode controller

These are Metal Film Resistor with a value of 680 ohm 2W and tolerance of ±5%

Switching Power Supply

Higher switching frequencies will allow you to design supplies with considerably wider control-loop bandwidth which can be provided by IRFB38N20

Periodic avalanche rated

510 ohm 1% 1/4 Watt Resistor (Box of 5000) - MFR 33K It can be used eitherThese are Metal Film Resistor with a value of 510 ohm 1 4W and tolerance of 1%. These Axial resistors are cylindrical in shape with copper plated steel leads extending from each end. Metal Film Resistor limit the flow of electric current using a Metal Film. The printed colour code rings, which are Green, Brown, Black, Black, Brown for these 510E resistors, make it easy to identify the value of these resistors. Specification Resistance Value 510 ohm