Abstract: The apparatus includes a first triac having terminals to which the control wire of a heater gas inlet valve solenoid or other heating element is connected and the apparatus further includes a second triac to which the control wire of an air conditioner compressor or other cooling element is connected. The triacs are actuated by respective optical coupling devices. One or the other of the optical coupling devices is selected by a switch to indicate whether the heater or air conditioner mode is selected. Whichever optical coupling device, and thus whichever mode, is selected, a timer circuit provides a selectable timing signal to cause the selected optical coupling device to periodically actuate or deactuate the associated triac to thereby activate or deactivate the solenoid or compressor (or other element) associated with the triac.

Abstract: An equipment protector and energy saving apparatus includes transient protection as well as under voltage protection by preventing the reduced voltage from being applied to motors and other apparatuses that may be damaged because of insufficient voltage being applied thereto. Provision is incorporated to protect for momentary low voltage transients and turn-on prevention, if the line voltage should be reduced below a predetermined value. Provision is also made for correcting for a small increase in line voltage which may occur when the operating equipment is removed from the line. A timing device may be incorporated therein in order to remove the protected equipment from the line for predetermined intervals of time.

Abstract: A control circuit for driving solenoids protects these devices from failure due to overheating caused by frequent on-off cycling. Control signals are passed through logic gates. A timer responds to the termination of a control pulse and disables the logic gate that passes signals to the load for a predetermined time, thus restricting the minimum off time of the solenoid. Minimum on time or maximum on or off times are not affected.

Abstract: A delay circuit comprising two leads adapted to be connected across a light switch for delaying the turn off of a light bulb after the switch has been turned off. A silicon controlled rectifier (SCR) is connected across the two leads for applying power to the bulb when the SCR is on. A capacitor is connected to one of the leads for controlling circuitry coupled to the gate of the SCR for turning the SCR on for a given time period following the opening of the switch. A quick discharge circuit is provided for rapidly discharging the capacitor when the switch is closed.

Abstract: A circuit for controlling the intermittent application of a dc potential to a device, such as a striker mechanism for a gong, having a member reciprocally moveable between rest and active positions. The reciprocating member shunts and unshunts a capacitor when the member is in its rest position and moved away therefrom, respectively. While the capacitor is shorted, and during its charge time, dc power is applied to the device. When the capacitor is charged to a predetermined potential, dc power is disconnected from the device thereby allowing the reciprocating member to return to its rest position to shunt the capacitor and initiate a new cycle of operation. The system is substantially independent of mechanical characteristics of the device and the current interrupted or made by the contact pair may be at least an order of magnitude less than the peak current in said device.

Abstract: A sequencer for two power supply voltages includes a master on-off switch, and two transistor switches which operate in response to the closing and then the opening of the master switch to turn on one voltage before the other is turned on, and to turn the one voltage off after the other is turned off. The sequencer is useful, for example, in connection with charge-coupled device apparatus.

Abstract: A domestic appliance comprises a programming device receiving on-time information and for updating, by way of repetitious signals, the on-time yet to be completed. The repetitious signals continuously activate an activation signal which is independently terminated if the repetitious signals do not appear. When the activation signal is present, first and second switching components are activated so that a discharge tube can emit ultraviolet radiation. A detection element detects whether the first and second switching components are deactivated outside the on-time. If one of the two switching components remains active outside the on-time, the detection element supplies a signal to inhibit the next start signal.

Abstract: The magnetic valve with electronic control for increasing the attractive output has an energizing coil (AE), which is supplied in the attracting phase with an increased energizing current via a closed switch (T2). In the maintenance phase, the energizing coil (AE) is supplied with a maintenance current, via a compensating resistor (RV) and with the switch (T2) opened, which is lower than the energizing current. For the purpose of controlling the switch (T2), a timing circuit is provided which includes a resistor (R2) and a capacitor (C2). The magnetic valve is selectively drivable with alternating current or direct current. A portion of the energizing coil (AE) is made up of the compensating resistor (RV), which is embodied as a resistor wire and wound up on the energizing coil (AE).

Abstract: Disclosed herein is an electronic timing circuit which can be incorporated in an accelerator pump timing control, also disclosed herein. The timing circuit is adapted to be connected to the first and second power terminals of a DC supply and for energizing a load, for example, a fuel pump solenoid valve, during a predetermined timed cycle. The circuit includes a thyristor having an anode-cathode path adapted to be connected to the load so that when the thyristor is rendered conductive by a trigger pulse applied to the gate, current flows from the DC supply through the thyristor to energize the load and start the timed cycle. A transistor control circuit including a transistor connected in series relation with the anode-cathode path is operable for controlling the energizing current flow through the thyristor, subject to a relaxation oscillator included in the timing circuit.

Abstract: An electrical device for protecting an alternating current network in which a static inverse time-overcurrent relay obtains network current information and relay circuit operating power from a current transformer having two secondary windings. Low transformer burden and accurate network information signals that are linearly responsive to a wide range of network current magnitudes are achieved through the use of a switching circuit that prevents the simultaneous operation of both secondary windings. The relay circuit employs an RC network with a short, precision time constant for curve shaping and employs digital counting techniques to provide time delay multiplication, precision time scale selection and a variable delay time variable in accordance with the magnitude of system current.

Abstract: An exposure factor switching circuit in a camera with an exposure control circuit having an emitter follower transistor adapted to apply a voltage through at least one transistor driven by a current flowing in the emitter thereof. A time constant circuit is adapted to control a shutter control magnet with an integration voltage due to a collector current of another transistor to the base of which the output of the emitter follower transistor is applied. A bias current supply circuit is employed having a plurality of transistors one of which is provided with a switch connected to the emitter thereof. The switch is operated to selectively activate the plurality of transistors to vary the emitter current of the emitter follower transistor.

Abstract: An adjustable time delay relay is provided which is particularly suitable for automatic transfer switches and other applications requiring a relatively long time delay during periods when electrical power is not available. The relay includes a relay coil connected across a large storage capacitor supplied from an AC power source through a diode.The timing function is provided by a separate timing capacitor which, upon discharge through an associated adjustable resistor, operates a switching transistor to establish a low impedance path across the relay coil, thus discharging the storage capacitor and de-energizing the relay. Such a construction eliminates the need for a close tolerance, high value storage capacitor and provides a high degree of time delay reproducibility despite variations in power supply voltage.

Abstract: A warning apparatus to indicate to a driver that the headlights of the vehicle have been left on after the ignition has been turned off includes a timer circuit which is operably connected to the ignition switch, the headlight switch, and the horn of the vehicle. The timer circuit energizes the horn for a predetermined period after the ignition switch is turned off while the headlight switch remains on.

Abstract: The coil of a relay is activated by a DC voltage directly through a primary switch, which voltage is also applied through a diode to charge a capacitor. A transistor biased by the same DC voltage is connected across the charging diode, but poled for conduction in the opposite direction. When the power is removed from the relay coil and the charging diode, the transistor is forward biased and conducts the charge from the capacitor through the relay to keep the relay energized until such time as the capacitor charge equals the transistor bias; then the transistor cuts off and the relay opens immediately. Relay energization is independent of the transistor; if the transistor fails open, the relay is disenergized instantaneously; if the transistor fails shorted, the relay is deenergized when the capacitor voltage drops below the dropout voltage of the relay; therefore, the circuit is fail safe.

Abstract: The timer circuit includes ramping circuit means for producing a substantially linear ramping voltage output signal. Control circuit means is provided for receiving a timer input signal and controlling the ramping circuit means wherein the presence of the timer input signal causes the ramping voltage output signal to ramp with a positive slope. Level detector circuit means is coupled to the ramping voltage circuit means to receive the ramping voltage output signal and to produce a level detector output signal when the positively ramping voltage output signal is of a predetermined threshold. The level detector output signal continues as long as the timer input signal continues and is coupled back to the control circuit means. The presence of the level detector signal develops a truncating signal which causes the positively ramping voltage output signal to truncate. When the timer input signal terminates, the ramping voltage output signal ramps negatively and the level detector signal terminates.

Abstract: A control circuit is provided for a contactor which has a pair of contacts and an actuator coil which is energizable under the control of a switch to cause the contacts to close. The control circuit provides a temporary path for energizing the coil and a permanent path through the contacts. The control circuit delays energization of the coil for a preselected time to allow switch contact bounce to cease. The control circuit prevents a reestablishment of the temporary path for preselected time after the contacts close.

Abstract: A circuit is described for energizing an electromagnetically operated fuel injector from an unregulated voltage source in response to an injection command pulse. The injector pull-in current is provided by directly coupling the unregulated voltage across the injector upon the initiation of the injection command pulse. The injector current is thereafter reduced to a lower hold-in value. The circuit is voltage compensated by a pair of timers the first of which compensates for the voltage dependent injector pull-in time by adjusting the time that the unregulated voltage is directly applied across the injector as a function of the value of the unregulated voltage to insure that the injector is energized for all values of the unregulated voltage while minimizing the time period that the unregulated voltage is directly coupled across the fuel injector.

Abstract: Improved sequential timing circuitry includes a relay coil, normally closed of form C relay contacts and a relay latching element, e.g., a resistor limiting relay coil current to a value intermediate pull-in and holding limit, serially connected to a high ripple D.C. source. A delay circuit selectively gates on a controlled switch to activate the relay, thereby advancing circuit operation to a next sequential task.In accordance with varying aspects of the present invention, the circuitry of the instant invention may be employed to sequentially excite plural relays with differing delay periods, or to delay turn-on of a master relay, as in a motor control application.

Abstract: Control apparatus is provided for a contactor which has a coil and at least one pair of contacts movable from an open position to a closed position in response to energizing the coil. The control apparatus includes apparatus for temporarily and permanently energizing the coil and switching apparatus for controllably energizing the coil.

Abstract: This disclosure relates to a timer for subdividing a finite time interval into a number of periods. An operational amplifier is connected as an integrator with a capacitor in its feedback path. An adjustable resistance network, enabling the selection of a fixed ohmic magnitude, is connected to the input of the operational amplifier and to a source of d.c. potential. A detector, connected to the output of the operational amplifier, determines when the capacitor has reached a fixed potential, by actuating a relay, the relay having normally open contacts in shunt with the capacitor, the closure of the contacts discharging the capacitor -- the charge-discharge cycle is then repeated. By selection of the ohmic magnitude for the resistance network, the operator can divide the time interval into equal periods in accordance with the number of times that the capacitor reaches the detected potential level.

Abstract: Alternating current energized appliances, particularly lamps, are extinguished in delayed fashion with the power delivered to the appliance being sharply reduced during at least the last portion of the extinction cycle. Delayed interruption of power is accomplished by means of a first circuit, including a series connected diode and heater, connected in parallel with the appliance and a second circuit, including a series connected diode and temperature responsive switch, connected in parallel with a main power switch. The heater and temperature responsive switch are mounted in proximity to one another and the diodes are arranged in opposition.

Abstract: A controller for initiating operation of a video tape recorder and for terminating operation when its power consumption drops to a predetermined level utilizes a power transfer circuit for coupling the recorder to a source of energizing potential. A normally open switch, included in the transfer circuit, responds to an actuating signal developed by an operational amplifier, which amplifier is activated by an enabling signal from a preset clock. Thereafter, the amplifier is controlled by a derived signal having an amplitude proportional to the current drawn by the recorder. When the energizing current for the recorder drops below a predetermined level, the derived control signal is now of insufficient amplitude to maintain the amplifier in an operating condition, as a result, the actuating signal for switch is interrupted and operation of the recorder is terminated.

Abstract: A circuit arrangement in an electrical device which contains a load which can be supplied with a direct-current voltage of lesser quality and electronic components which can be supplied with a direct-current voltage of greater quality, especially in a timing relay for supplying the device with energy from an alternating-current network by means of a transformer or voltage divider connectable with the alternating-current network and a subsequently connected rectifier arrangement. The rectifier arrangement connected after the transformer has an output at which there are connected a first supply branch and via a reverse current barrier a second supply branch containing smoothing means and a voltage stabilizer. The load which is to be supplied with the direct-current voltage of lesser quality is connected at the first supply branch and the electronic components to be supplied with the direct-current voltage of greater quality are connected at the second supply branch.

Abstract: This disclosure relates to a fail-safe time delay circuit for providing a definite time interval. The time delay circuit includes a resistance-capacitance charging network which is connected to a source of a d.c. supply source by a switching device. The potential charge developed on the capacitor powers an inverter to produce a.c. signals having a given frequency. The a.c. signal is fed to a multi-stage tuned amplifier having a resonant circuit tuned to the given frequency. The amplified a.c. signals are applied to a voltage doubling network which normally energizes a load and which maintains the load energized for no longer than the definite time interval after the opening of the switching device.

Abstract: A control circuit includes two full-wave rectifiers connected to an AC power source to produce two rectified outputs having different phases with respect to each other, a combining circuit for combining the two rectified outputs to produce a composite output, and a switching means controlled by the composite output. The switching means generates a control signal nearly at the same time that the AC power supply is switched on or off. The control signal is used to energize a device at a delayed time after the AC power supply is switched on, and to de-energize the device substantially at the same time that the AC power supply is switched off.

Abstract: A switching circuit designed to start operation after the lapse of a predetermined delay time from its connection to a power source. The switching circuit has a switch element which is rendered conductive when the terminal voltage of a capacitor of a time constant circuit connected to the power source for determining the delay time has reached a predetermined value. Thereafter the electric charge of said capacitor is quickly discharged through a low impedance discharge line including said switch element.

Abstract: A solid state timing valve control system and unit is provided which may be battery operated, and which has particular although not exclusive utility for controlling a water lawn sprinkler system. The control unit of the invention may be coupled to a water control valve in the sprinkler system, and it acts automatically to turn the valve on at the start of each of a succession of preset watering cycles, and to turn the valve off after a preset watering time at the completion of each such cycle. The control unit includes a latching-type solenoid for controlling the water control valve. The unit also includes a solid state miniaturized electronic system for introducing a turn-on pulse to the solenoid at the start of each preset watering cycle, and for introducing a turn-off pulse to the solenoid at the completion of each cycle.