I am making a constant current source as an adjustable. The maximum current flowing is 1 A. I fixed the current at 570 mA, using a BDX53 BJT. BJT collector emitter voltage is 10 V. This circuit also has a square wave but not completely within the transistor's base, collector and emitter voltage. But it fixes square wave to constant wave with the aid of capacitor and coil. So load voltage is a constant current as well. My problem is a BDX53C heating up over time while BDX53C powers only 6 W.
How can I fix it?