My recent DI contribution (Another silly simple precision 0/20mA to 4/20mA converter) used the LM337 regulator in a novel circuit arrangement to translate an input 0-20 mA current source into a 4-20 ...
A well known power supply circuit is the capacitance multiplier. It doesn’t regulate, but instead reduces ripple & noise while the output tracks at some fraction of the input voltage. The effect of ...