Three circuits from left (clockwist/rightward) for battery-operated current limiting: simple control, BJT current limiter from https://electronics.stackexchange.com/questions/149504/how-do-i-build-a-10ua-current-source-limiter, and a new idea for charge-current shaping. None have specific (or actual!) discrete devices. Play around with component-value sensitivities! Also, compare peak voltage values (to the left of the main PMOS).
