Burns, Doane, Swecker & Mathis
Multiple-purpose closed-loop, automatic control system
 A multiple-purpose, closed-loop, automatic control system comprising: PA1 a system controlled; PA1 a detecting means for detecting a controlled variable output from the system controlled and converting the controlled variable into an electrical feedback signal; PA1 a signal converting means for receiving the feedback signal and converting said signal into an angular displacement corresponding to the feedback signal; PA1 a comparing means for comparing the controlled variable with a preset desired value and selectively opening or closing a forward or a reverse controlling circuit; PA1 a controlling means including the forward and the reverse controlling circuit selectively opened or closed by said comparing means, a braking control circuit and a driving mechanism responsive to said forward and reverse control circuits and said braking control circuit for automatic control over the system controlled to keep the controlled variable within the preset desired value. 
G
G05B
inventional
Yu-Kuang
Lee