How to switch a large-V load with a P-channel mosfet and small-V unipolar clock?

i can switch the supply voltage with a unipolar clock, if the clock has the same peak V as the source supply

but if i make the source V higher than the gate V, i get a flat line output.

How to switch a high-V load with a low-V gate, on a P-channel mosfet?

Thx

Third diagram on this page shows how to switch a higher voltage high-side with a 5volt input signal.
Small transistor works as level shifter, and the second transistor as the actual switch.
Leo..

For 16V supply and above you need a more carefully designed level shifter that never pulls the p-FET gate more
than 12V negative of its source - typically a 12v zener is used between source and gate for this, and a current
limiting resistor is needed on the collector of the level-shifting NPN transistor.

What max frequency will this clock signal be? The bandwidth of the level shifting circuit may be important.

The fourth diagram on that page shows a circuit for a >12volt supply.
Leo..