An analog to frequency converter is disclosed for receiving a first analog signal and a frequency signal to provide a second first frequency signal. Another analog to frequency converter may provide the first frequency signal having a frequency dependent upon the magnitude of another analog signal. Circuitry is provided so that the second frequency will exhibit a frequency proportional to the product of a function of the first and that of the second analog signals.

A reliable signaling device is provided which will allow an operator of a reactor vessel to ascertain when a leak has occurred in the reactor vessel rupture disc or diaphragm. The signaling device is actuated by pressure which escapes through a leak in the rupture disc. The signaling device makes the operator aware of when a rupture disc is leaking and thereby avoids a potential hazard of the reactor vessel exceeding its designed pressure rating. The signal device when modified may also be used ...

A signal device is disclosed suitable for mounting upon a mailbox to indicate incoming or outgoing mail. The signal device includes a pocket and a pair of flags mounted on either end of a pivotal arm. The flags are adapted for alternate exposure or for concealment of both flags within the pocket.

A timing generator which may be used for multiple-cycle controllers is disclosed. A Johnson counter which may have a selectively operable delay interposed between successive stages is utilized with an oscillator and a plurality of multiplexers to provide a plurality of timing pulse train cycles. Circuitry is provided to eliminate spurious output signals from the timing generator.

A mailbox signal including a flag member journaled beneath the mailbox and adapted to be held in its elevated inoperative position by a latch member, also mounted beneath the mailbox and adapted to be actuated by the rearward swinging movement of the bottom portion of the mailbox door when swung to an open position, for disengaging the flag member and permitting it to drop to a visibly exposed operative position. The invention also contemplates an extended signal member pivotally mounted upon th...

A lamp included in electric fences, at one or more posts thereof. The lamp indicates when an electric charge is flowing through the electric wire, at full charge, partial charge or no charge.

A signal processor having a plurality of charge transfer devices fed by a series of input signals, input addressing circuitry for enabling sequential samples of such each one of input signals to be stored in corresponding ones of the charge transfer devices, such charge transfer devices storing corresponding sets of samples, output addressing circuitry for reading, sequentially, the sets of samples, the charge transfer devices, input addressing circuitry and output addressing circuitry being for...

A circuit is provided for protecting an amplifier from signal overload upon the application of strong signals at the input to the amplifier. A unidirectionally conducting semiconductor device and a capacitor are serially coupled between the input to the amplifier and ground. Means for maintaining a constant voltage is coupled to the junction of the semiconductor device and the capacitor. Upon the application of a strong signal at the input to the amplifier, the semiconductor device conducts curr...

An improved signal expansion system and technique is disclosed. The system comprises a detector for sensing an input signal and for producing responsively thereto a D.C. control signal having an amplitude as a function of the input signal, and a gain control amplifier for amplifying the input signal, the amplifier including means for controlling the gain of the amplifier as a function of the amplitude of the control signal. The improvement comprises means for varying the amplitude of the D.C. si...

A signal classifier performs measurements on an IF signal and determines from these measurements the nature of the modulation, if any, appearing on a received high frequency communications signal. The classifier distinguishes between double sideband AM, single sideband suppressed carrier voice AM, ASK, FSK, multi-channel FSK, unmodulated carrier and noise. The measurements include AM variation, the zero crossing rate in detected AM, the percentage of time the detected AM signal level exceeds a g...