When I did something like this we called it blind chopping. We had an inductive (motor) load, which we wanted to drive at a constant current. To get the current up as quickly as possible, we applied the full voltage for long enough to get to our target, and then chopped at a fixed duty cycle to keep it there. A current sensing chopper would do this automatically, but if your supply voltage and load impedance don't vary, you can dispense with the current sensor.