Abstract: In an impressed current cathodic protection system for a boat and/or its propulsion system the boat battery is connected to a switching type power converter which supplies the anode higher current at lower voltage than taken from the battery. The voltage on the anode is regulated to be constant or to be fixed relative to the voltage at a reference half cell. With either arrangement, the voltage drop across a reference resistor can be applied to an op amp to turn on a transistor to connect an alternate power source to the anode. The voltage across the resistor is regulated by the power converter chip so the chip also regulates the alternate source to prevent excessive voltage on the anode.

Abstract: A marine propulsion unit having a housing exposed to sea water and subject to attack by the sea water is provided with a permanent type anode housing substantially constant surface characteristics mounted on the housing and supplied with constant voltage. Holes under the anode through the housing to interior passages permits the current on the anode to influence and protect the passages.

Abstract: A marine propulsion device is provided including a lower unit having a gearcase and a propeller shaft housing located in the gearcase and supporting a propeller shaft for rotation. A propeller is mounted on the propeller shaft rearward portion for common rotation with the propeller shaft. A thrust bushing is carried by the propeller shaft and for transmitting forward thrust from the propeller to the propeller shaft. An annular sacrificial anode surrounds the propeller shaft and is positioned between the thrust bushing and the propeller shaft bearing housing for providing cathodic protection for the rearward end of the gearcase and the propeller shaft bearing housing.

Abstract: The linear motion power assist mechanism includes a stationary member, a friction drum rotatably supported on the stationary member, an output member mounted for linear, reciprocative movement relative to the stationary member, an input member mounted for linear, reciprocative movement relative to the stationary member and relative to the output member, a first flexible member, such as a wire cable, loosely wound around the drum in one direction, a second flexible member loosely wound around the drum in the opposite direction, and an unidirectional motor rotating the drum. The first cable is tightened on the rotating drum and pulls the output member in a first direction in response to movement of the input member in the first direction. The second cable is tightened on the rotating drum and pulls the output member in the opposite or second direction in response to movement of the input in the second direction.

Abstract: Disclosed herein is a multiple spark circuit for use with a capacitor discharge ignition system including a current supply, a charge capacitor, an ignition coil primary winding, and an ignition timing SCR. The multiple spark circuit includes a charge reservoir capacitor connected to the current supply, a restrike circuit subject to the timing SCR, and to the voltage and discharge current of the charge capacitor, for allowing repeated charging and discharging of the charge capacitor to produce multiple ignition sparks at each ignition timing point, and a charge interrupt circuit, subject to the restrike circuit, for allowing repeated charging of charge capacitor by the charge reservoir capacitor at each ignition timing point. The restrike circuit preferably comprises a thyristor connected to the timing SCR and charge capacitor, and a zener diode connected to the thyristor gate and anode to render the thyristor conductive when the charge capacitor voltage exceeds a predetermined upper limit.

Abstract: A reversible motor is coupled to the stern leg of a watercraft for angulating the leg up and down through a trim and tilt range. A manually settable device provides a voltage signal corresponding to the desired trim angle and a position sensor provides a voltage signal corresponding to the present stern leg position. A first comparator changes the state of its output if the difference between the signals has one polarity and a second comparator changes state for the opposite polarity. The state changes turn on one of two transistor switches which provide an up or a down signal, respectively, to a motor control circuit for causing the motor to run until the difference is nulled. When the active transistor switch turns off, the other delivers a momentary pulse for plugging the motor.

Abstract: Disclosed herein is an alternate action solenoid drive circuit adapted for connection to a DC source having first and second power terminals and which can be incorporated in a DC motor control for a vehicle, also disclosed herein. The drive circuit comprises an actuator switch including go and stop terminals, and an actuator switch operable in response to movement of a foot pedal for alternately moving between a go position connecting the go terminal to the first power terminal and a stop or off position connecting the stop terminal to the first power terminal. The drive circuit includes a thyristor having an anode connected to the go terminal, and a cathode and a gate, a sequencing solenoid including a solenoid coil having one end connected to the cathode and an opposite end connected to the second power terminal, and a parallel RC network connected in series between the stop terminal and the thyristor gate for applying a trigger pulse to the gate when the actuator switch is moved to the off position.

Abstract: Disclosed herein is a capacitor discharge ignition system including a U-shaped magnetic core having a pair of legs, and a rotatable member including a magnet having arcuately spaced first and second pole shoes located for movement past the core legs, the second pole shoe having a length greater than the distance between the core legs and trailing the first pole shoe relative to a normal direction of rotation of the rotatable member.

Abstract: Disclosed herein is a rotary pulse generator including an armature having a two-magnet assembly including spaced pole pieces defining a pair of spaced gaps, an armature plate including a charge core and charge coil mounted thereon, and a trigger core and trigger coil mounted thereon, said trigger core being separate from said charge core but located in proximity to said charge core so that, at a given armature speed, said trigger coil produces a repeating series of trigger pulses including a first major voltage pulse of one polarity and of a major magnitude closely followed by a second minor voltage pulse of opposite polarity and of a minor magnitude substantially less than the major magnitude, the repeating series of trigger pulses being produced in response to the two-magnet assembly sequentially rotating past the trigger core and the charge core.

Abstract: Disclosed herein is a digital timing control system for an internal combustion engine comprising a processing circuit for receiving a cyclical engine timing reference pulse and for producing a cyclical control pulse offset from the reference pulse. The processing circuit includes a counter connected to a NAND gate for producing a control pulse when the counter reaches a preset count, a monostable device, subject to the control pulse, for resetting the counter, an oscillator for providing preload pulses to the counter for a predetermined period of time to establish a preload count, and a phase-locked loop, subject to the reference pulse, for transmitting a fixed number of signal pulses per engine revolution to the counter to increment the preload count until said preset count is reached, whereby the control pulse is produced.

Abstract: Disclosed herein is a control for a direct current motor including a field weakening solenoid switch including a solenoid coil, which control includes an electronic switch connected in series with the coil for selectively connecting the coil to a source of direct current, and a device adapted for providing an electronic digital signal having a frequency proportional to motor speed.

Abstract: Disclosed herein is a thyristor interlock circuit for energizing a DC motor, the circuit comprising a solenoid switch including an actuating coil, the solenoid switch and the motor being connected in series relation between the opposed terminals of the DC source, a thyristor having an anode, a cathode, and a gate, an ignition switch which connects the anode to one terminal of the DC source, a start switch normally biased to an open position, the start switch being linked to close after closing of the ignition switch, the start switch being connected to the one terminal of the DC source and to the gate, a resistor for limiting the gate current, a controller having a switch with two terminals, and a sub-circuit comprising a first lead including a first resistor and connecting the first resistor and the actuating coil in series relation between the thyristor cathode and the other terminal of the DC source, a second lead connecting one terminal of the controller switch to the start switch and the gate, a third le

Abstract: Disclosed herein is a direct current motor control circuit adapted for connection to first and second supply terminals of DC power source and to a DC motor connected between the positive and negative terminals of a DC power source, the control circuit including a solenoid including a solenoid coil having one end connected to the first supply terminal and having an opposite end, and having a pair of solenoid contacts connected in series relation with the DC motor between the positive and negative terminals and which close to energize the DC motor when current flows through the solenoid coil.

Abstract: Disclosed herein is an engine ignition system comprising a charge capacitor, first and second ignition coils respectively including first and second primary windings and first and second secondary windings connected respectively to first and second spark plugs, first and second electronic switches respectively including first and second anodes connected respectively to first and second primary windings, first and second cathodes connected to the charge capacitor, and first and second control elements operable, upon application thereto of a trigger current pulse, to cause the first and second switches to be conductive, and which employs rotary pulse generator means including a relatively rotatable magnet and trigger coil for generating trigger voltage pulses in response to engine rotation, the trigger coil having first and second ends respectively connected to the first and second control elements, a first diode having a cathode connected to and between the first end of the trigger coil and the first control e

Abstract: Disclosed herein is a control for a direct current motor including a field weakening solenoid switch including a solenoid coil, which control includes a switch connected in series with a coil for connecting and disconnecting the coil to a source of direct current, and a device responsive to motor speed for operating the switch.Also disclosed herein is an overspeed control for a direct current motor including a solenoid switch which controls energization of the direct current motor, which is biased open, and which includes a solenoid coil operable in response to energization thereof to close the switch, which overspeed control comprises a switch connected in series with the coil for selectively connecting the coil to a source of direct current, and a device responsive to motor speed for operating the switch.

Abstract: Disclosed herein is an ignition system comprising a coil mounted on a core having first and second spaced legs, together with a rotor mounted for rotation, under normal operating conditions, in one direction relative to the core such that any point on the periphery of the rotor passes the first leg prior to the second leg. The rotor includes a magnet having arcuately spaced first and second poles and first and second pole shoes extending respectively from the first and second poles.