RE:When the negative wave has been blocked, you have a pulsating direct current.
Yes, but nowday, with the use of rectifiers and diodes, it a rather simple operation to convert a pulsating direct current into a rather stable direct current.
zener diodes are used to limit the upper portion off the wave, and (okay, so i don't remember all my physics!) something else controls the lower half of the wave form.
the same sort of thing is used all the time in analog to digitital conversion.. the analog signal is converted into a pulsating direct current, which is further refined into digital pulses--frequentcy modulation, -- with all sort of circutry built in to comp for dopler effects.
(a long ago standard for hard drives was Modified Frequency Modulation.. MFM, aka mother f****** magic), details from the dredges of my mind..
