Abstract: A dual temperature curling iron has a plastic handle and a metal barrel connected thereto. An electric heater positioned within the metal barrel and is arranged to rapidly heat the barrel and is selectively controlled by either a low temperature thermostat or a high temperature thermostat located within the barrel to provide heat to the metal barrel. A hair clamp is pivotally mounted on the metal barrel, and when opened, causes a switch to generate an in-use signal which is fed to a safety timing circuit. The timing circuit is reset each time it receives the in-use signal. In the event that no further in-use signals are received, the timing circuit, after a preselected interval, provides a signal to a silicon controlled rectifier which is connected to the electric heater causing the silicon controlled rectifier to interrupt electric power to the electric heater. The curling iron is provided with a visual signal for indicating that has reached the selected temperature and is ready for use.

Abstract: An electronic pressing iron having a soleplate and a housing connected to the soleplate is disclosed herein. An electric resistance heating element is mounted in the soleplate for receipt of an alternating current from a suitable source. A temperature control thermostat is connected in series with the electric heating element and is mounted in good heat conduction relationship with the soleplate to control the temperature thereof. A motion and attitude sensing switch is mounted in a handle of the housing and provides a motion signal to a programmable timer also mounted in the handle. A thermal relay mounted in the handle is connected to the programmable timer to receive a time out signal therefrom. When the electronic pressing iron is switched on and is stationary with its soleplate oriented horizontally, for a period of thirty seconds, the programmable timer signals the thermal relay which interrupts the electric current flowing through the heating element.

Abstract: A food preparation appliance including a housing, an electric motor supported in said housing and adapted to receive alternating current. A tachometer senses rotation of said electric motor and feeds a tachometer signal to a frequency to voltage converter. A conversion ratio between said tachometer input signal and an output signal of said frequency to voltage converter is alterable by actuating a timer which causes a speed of the electric motor to decrease. The output signal of the frequency to voltage converter is supplied to an error amplifier where it is compared with a setpoint signal to generate an error signal supplied to a triac which controls a flow of electric power through the electric motor.

Abstract: A magnetic tachometer sensor for a motor control circuit having a motor driven interrupter wheel in proximity thereto supplies a motor speed signal to a frequency to voltage converter. The frequency to voltage converter produces a DC signal proportional to the speed of the interrupter wheel. The DC signal is compared to a user selected reference voltage in an error amplifier, thereby producing an error signal. The error signal is supplied to an output comparator which also receives a sawtooth timing reference signal in synchronism with power supply alternating current. The output comparator switches to trigger a triac into conduction when the sawtooth signal voltage exceeds the error voltage, thereby providing highly accurate timing of the switching point of the triac. The triac is arranged to provide a phase angle speed control for an electric motor used in a household appliance.