Townsend and Townsend
Arc discharge preventing circuit of transfer switch for use with inductive loads
 A motor is energized by a source through first and second transfer switches. Each transfer switch is operated by a switching transistor. The switching transistor for the first transfer switch is driven by a drive signal while the switching transistor for the second transfer switch is driven by the output of a delay circuit responsive to an excessively large current flowing through the motor. A self-holding switch is provided to connect the motor to the source through the second transfer switch. 
JECO Co. Ltd.
Y B
Y10S B60S
additional inventional
Toshihiro
Mori