Current limiting impedance network for dryer control

DETAILED DESCRIPTION The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 1.
In an automatic clothes dryer of the type having a control circuit wherein an AC motor which is connected to an AC electrical supply is shunted by a controlled conduction device to selectively shunt one half of the AC wave to prevent operation of the motor, and a current limiting means is connected in series circuit with the controlled conduction device and the motor to limit the current through the controlled conduction device during its conductive condition, the improvement wherein: said current limiting means comprises a resistor and a capacitor connected in series with said resistor, said capacitor having a capacitive reactance which is approximately twice the inductive reactance of the motor to provide a capacitive circuit impedance and operation of the circuit with a leading current phase angle.
2.
The improvement set forth in claim 1, wherein said resistor and said capacitor have a time constant sufficient to maintain the current through the controlled conduction device above its holding value for the duration of each of said one half of said AC waves to prevent turn-off of the controlled conduction device and energization of the motor.
3.
An automatic clothes dryer comprising: a timer motor for connection to an AC electrical supply, said timer motor being incapable of operation in response to half-wave energization; an SCR connected in parallel with said timer motor and including a gate for receiving gate signals for rendering said SCR conductive; circuit means connected to said gate and repetitively providing gate signals thereto to render said SCR conductive during alternate half cycles of the AC wave; and current limiting means connected in series with said SCR, said current limiting means including a resistor, and a capacitor connected in series with said resistor and having a capacitive reactance substantially equal to twice the inductive reactance of said timer motor