Abstract: A motor speed control circuit for closed loop control of an electric motor of a household electric appliance is disclosed herein. The motor speed control circuit includes a coil adapted to be placed in proximity with a fan connected to an electric motor and producing a time varying signal in response to rotation thereof. A comparator connected to the coil generates a rectangular wave having a frequency proportional to the frequency of the coil signal. Additional means are provided for converting the rectangular wave signal, a D.C. signal having an amplitude which corresponds to the frequency of the rectangular wave. The D.C. signal is compared to a reference signal at an amplifier to produce an error signal which is fed through an opto-isolator to a conduction angle controlled thyrister. The thyrister is connected to the electric motor and a source of electric power to control the speed of the electric motor.

Abstract: A travel iron having a handle which pivots sideways between an upright "use" position and a flat "storage" position wherein the handle is pivotally mounted on the main body portion of the iron at its rear end only and wherein cam ramp and pin means provide longitudinal forward and rearward movement of the handle during its pivotal movement whereby to stabilize both ends of the handle when the handle is in its upright "use" position. A pump actuator mounted in the main body portion of the iron is actuated by a plunger slidably mounted in the handle. A dual-voltage sole plate heating circuit has a pair of identical heating elements connected in series in one voltage position of a dual-voltage switch and in parallel in the other voltage position with the output wattage being the same in both voltage positions of the switch.

Abstract: A steam iron has a water storage tank, an evaporation chamber to provide steam for ironing, and a drip valve for regulating the flow of water from the tank into the evaporation chamber. A pressure chamber in the tank is connected to the evaporation chamber via a pressure equalization passage. The pressure chamber is also connected to receive water from the tank via a non-return valve and is connected to feed water to said evaporation chamber via said drip valve.

Abstract: An electric blanket having a terminal block for connecting the tortuous flexible heating element of the blanket to a detachable power cord with the terminal block being mounted by means of flexible tabs positioned on strain relief members, the tabs being sewn or stitched to the blanket shell with a portion of the terminal block extending through a slot in the blanket shell.

Abstract: An electrically heated steam iron operable by a drip system includes a drip valve arranged to have a variable rate of flow of water therethrough, and a water tank the interior of which is vertically divided into two chambers and by a partition wall, the two chambers being in flow communication with each other via an opening. A vaporizing chamber is disposed below the drip valve. A vertically adjustable slide member is arranged to slide relative to the partition wall while being sealingly engaged therewith, and adjustment means comprising a valve rod is connected to the slide member. The valve rod passes through a top surface of the tank, wherein vertical adjustment of said slide member by means of the valve rod is effective to vary the height of the column of water above the drip valve, thereby adjusting the rate of flow of water.

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 non-resettable water actuated circuit interrupting means for use with a portable electric appliance such as a hair dryer to provide protection for the user against injury in the event that the appliance is accidentally dropped in water or otherwise develops leakage current. Both sides of the line are fused and circuit means are provided which respond to leakage current in the appliance to provide separate circuits to blow out each of the fuses.

Abstract: A heating cable for use with an electric underblanket the cable being of the type in which a sensor wire is employed coextensive with a heater wire and separated by a layer of meltable insulating material so that overheat conditions are sensed by contact between the sensor wire and the heater. A number of helically wound coextensive wires cooperate with switching means to provide overheat temperature sensing at various wattage levels of heating.

Abstract: A process for the separation of a mineral acid from a common ion salt comprises a step of flowing a quantity of the mineral acid and salt in aqueous solution onto a strong base common ion form anion exchange resin bed whereon the mineral acid is retarded with respect to the salt. The salt is removed from the anion exchange resin. An interface cut of the mineral acid and the salt is recirculated from a bottom portion to a top portion of the anion exchange resin for further separation. A quantity of water is flowed through the anion exchange resin bed to elute the mineral acid therefrom. A portion of the elutant fluid is recycled to the top of the anion exchange resin bed.