Abstract: A balanced receiver providing significantly reduced vibration is disclosed. The balanced receiver comprises a closed loop operably attached between an armature and a diaphragm. The effective moving mass of the diaphragm is designed to match the effective moving mass of the armature. The closed loop facilitates the balancing of the motion of the diaphragm and the motion of the armature, thus reducing the vibration of the receiver.

Abstract: A microphone assembly generally for hearing aid and communications applications is disclosed. The microphone assembly operates in both directional and non-directional or omni-directional modes. The microphone assembly has front and rear sound inlet tubes, and an actuator switch that may be moved between a first position in which the rear tube is plugged, defining the omni-directional mode, and a second position in which the rear tube is unplugged, defining the directional mode. Circuitry senses the position of the actuator switch and selects a microphone output based on the position sensed.

Abstract: A balanced receiver providing significantly reduced vibration is disclosed. The balanced receiver comprises a closed loop operably attached between an armature and a diaphragm. The effective moving mass of the diaphragm is designed to match the effective moving mass of the armature. The closed loop facilitates the balancing of the motion of the diaphragm and the motion of the armature, thus reducing the vibration of the receiver.

Abstract: A night set-back thermostat which may or may not be operable on a two-wire line with one or two series switches and with the possibility for provision of digital time, temperature or other storage and/or data entry or reentry apparatus therefor.

Abstract: An ignition system for heating appliances which burn gas or vaporous fuels. A spark igniter is programmed to ignite a pilot burner which in turn ignites a main burner. A flame rod is used to confirm to the control circuitry that pilot ignition has taken place before the main gas valve is opened. An initially closed timing control circuit opens the pilot gas valve but times out if ignition of the pilot does not occur within a predetermined time. Other circuit interlocking features are provided for overall fail-safe operation.

Abstract: A system for trial period ignition of a fluid fuel burner having an oscillator with a gate in the feedback path thereof, the oscillator providing power to a burner fuel valve and to a spark generator, wherein oscillator operation is sustained after the period only upon flame detection which keeps the oscillator feedback path gate closed.

Abstract: Apparatus including an improved D.C. operated oscillator for an intermediate power source, a cooperating solenoid gas valve opening and safety shut-off circuit, and a spark igniter with automatic shut-down.

Abstract: A system for igniting, by a spark, the main burner of a gas fired device without the use of a pilot light from, for example, 12 or 24 volts. A unique oscillator provides the spark power and voltage. The oscillator also supplies the power to open the gas valve. A capacitor momentarily opens the valve. The valve is maintained open when a flame is present at the main burner.

Abstract: A system for igniting, by a spark, the main burner of a gas fired device without the use of a pilot light from, for example, 12 or 24 volts. A unique oscillator provides the spark power and voltage. The oscillator also supplies the power to open the gas valve. A capacitor momentarily opens the valve. The valve is maintained open when a flame is present at the main burner.