Abstract: A digital click removal and squelch control circuit for a digital FM receiver. The digital receiver generates a series of binary number electrical signals each of which is representative of the instantaneous phase angle of a received frequency-modulated electrical signal or signal derived therefrom. The phase angle signals are differentiated to produce binary number electrical signals that represent the rate of change of phase angle, or, the instantaneous frequency of the received signal. During a given time interval, the phase change caused by the modulation of the received signal must be within a range determined by the bandwidth of the received frequency-modulated signal. Phase changes outside of this range represent electrical noise or clicks and are removed by the click removal circuit of the invention.

Abstract: Method and apparatus for testing DC motors, particularly permanent magnet DC motors, involving application of a constant voltage across the motor terminals and at an earlier or later time causing a constant current to flow through the motor. The constant voltage is applied across the motor terminals for a first predetermined time interval during a portion of which the current flow through the motor is compared with a reference level. If the motor current falls below the reference level during the portion of the first predetermined time interval the motor is defective. The constant current is caused to flow through the DC motor for a second predetermined time interval. If at the end of this second predetermined time interval, the DC motor terminal voltage is below a first level or above a second level, that is, the terminal voltage is outside an established voltage range, then the motor is found to be defective.

Abstract: A warning circuit particularly suited for indicating that an intermittently operated device has been operated for a predetermined cumulative length of time. The circuit utilizes a coulometer as a current integrator that accumulates the intermittent periods of time during which the device operates. At the end of the predetermined cumulative length of time, the impedance of the coulometer changes from a low level to a relative higher level. This change in impedance renders a first transistor conductive and results in a warning indication. A second transistor is latched into a state of conductivity that causes a feedback current to flow through the coulometer to maintain it in its high impedance condition. The warning indication is controlled by an amplifier circuit which, in turn, is controlled by the second transistor.

Abstract: A critical liquid-level warning circuit for association with a liquid-level indicating circuit, the indicating circuit including a sensing device that provides a voltage which varies between upper and lower voltage limits as a function of the level of a liquid. The warning circuit is particularly suitable for use in indicating a low fuel level in the fuel tank of a vehicle and, in the preferred embodiment, includes a first operational amplifier responsive to the sensing device voltage and a second operational amplifier that controls the actuation of a warning device. A delay circuit is interposed between the first and second operational amplifiers. The output of the first operational amplifier changes from one condition to another condition upon occurrence of a critical liquid level. The delay circuit provides a voltage which varies in magnitude as a function of time elapsed subsequent to the change in condition of the output of the first operational amplifier.

Abstract: An electronic ignition system for a spark-ignition internal combustion engine. The ignition system is of the inductive type and includes an ignition coil having at least a primary winding and a switching device connected in series with it to control its current. An electrical signal is generated having a period equal to the period of the ignition cycle of the engine. This electrical signal is used to control at least one constant current source and a constant current drain coupled to at least one capacitor. The charging and discharging of this capacitor determines the initiation of current in the ignition coil primary winding and determines the length of time current is present in the ignition coil primary winding during each ignition cycle.

Abstract: Capacitor discharge ignition system for a spark-ignition internal combustion engine. The ignition system employs an ignition coil having primary and secondary windings wound on a ferromagnetic core, preferably made of a ferrite material. A first capacitor is connected in series with a spark gap and this series combination is connected across the ignition coil secondary winding. The ignition coil primary winding has a second capacitor coupled to it which capacitor is charged and then discharged in timed relation to engine operation. The first capacitor and ignition coil windings and construction are selected such that the second capacitor when discharged through the ignition coil primary winding produces ferroresonant oscillations in the secondary circuit of the ignition coil. This breaks down the spark gap and an alternating voltage, at the ferroresonant frequency, occurs.

Abstract: A motor pump wherein the motor is a variable reluctance motor having a rotor which functions as an impellor to provide pumping action as a result of centrifugal force acting upon a fluid supplied to the motor pump. The motor pump is extremely simple in that it has only one moving part, its rotor, which is formed of a plurality of ferromagnetic elements spaced from one another with flow passages located between the elements. Fluid enters the pump on the radially inner side of the ferromagnetic elements and flows radially through the flow passages to the pump discharge outlet.

Abstract: Improved apparatus for supplying fuel to one or more fuel injectors used to inject fuel into a combustion engine. In the preferred form, each of the fuel injectors has its discharge port positioned in the engine intake manifold and a clamp retains the injector in position thereon. The clamp has a first portion that has a passage for receiving the inlet conduit to the fuel injector. Also, this portion of the clamp has inlet and outlet passages in communication with the passage receiving the injector inlet conduit so that fuel supplied to the inlet passage flows into the inlet conduit of the fuel injector and also flows out of the outlet passage. A second portion of the clamp is used for securing the clamp to the engine intake manifold. The fuel injector is located between the first portion of the clamp and the intake manifold. Flexible conduit may be used to connect the outlet passage of one clamp with the inlet passage to another clamp.