
518
capacitors in both left and right hand columns remain practically
constant, but relative to the right-hand (output) column the left-
hand one as a whole rises and falls in potential between —Ε and + Ε
owing to the generator.
27.11 Switch-mode Power Suppliers
A useful development in power suppliers is the 'switch-mode* circuit
in which the output from a mains rectifier feeds an astable pulse
generator such as a multivibrator. This regularly chops the rectifier
output to form an alternating voltage which is transformed, rectified
and smoothed to give the required z.f. output voltage. This may
seem an unnecessarily complicated method of obtainin ...