Shift Interrupt method for a Marine Propulsion System

Abstract

Device designed to retrofit a marine propulsion system from an old shift interrupt control strategy with a new shift interrupt control strategy to improve shifting performance, reliability, and ease of use. Can also be used on new systems.

Claims

1. Method to input using a Hall effect sensor latch. The Hall sensor may either contain a built in latch or have an external latch circuit. Shifting is implemented only when a Hall Sensor detects a change in position and direction of passing magnets. Specifically, detects a change from North to South and activates the shift delay. A change from South to North resets the circuit ready to be triggered again by a N to S polarity, or vice versa and depending upon the pole orientation of the magnets. The width of these magnets can be increased to change the length of time of the shift interrupt.

2. Method to control and use the information obtained from the sensor (in claim 1) to accurately control the time in which the engine coil is interrupted. The sensor directly triggers a One Shot Circuit (Monostable Circuit) (which then provides an output to the method in claim 3) for a duration determined by an RC Time constant adjusted via potentiometer or alternatively as described in claim 5.

3. Method to interrupt using the specified time duration determined using the circuit in claim 2. The positive connection to the engine coil may be interrupted via a Normally Closed relay, MOSFET, IGBT, or Solid State equivalent. Alternatively, the Coil may be grounded out via a Normally Open relay, MOSFET, IGBT or Solid State equivalent.

4. Alternative method to supplement claim 1 if the sensor doesn't have a built in latch, a logic circuit or flip flop circuit may be used. The circuit remembers the last output state of the hall sensor.

5. Method to Supplement claim 2 adding ability to monitor the engine RPMs and add or subtract capacitance or resistance in the RC Time circuit to change the delay interrupt time accordingly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a Simple Block Diagram

[0022] FIG. 2 is a One Shot Monostable Multi-Vibrator control circuit. The values of R and C determine the duration of the output pulse width. Time=RC When pin 2 detects a falling edge, the circuit is triggered for the duration of time determined by the RC time constant.

[0023] FIG. 3 is a Hall Sensor Trigger Circuit. This circuit substitutes the trigger Switch in the One Shot schematic in FIG. 2. A passing magnetic field causes the DO output to turn on or off and is Coupled through the capacitor to trigger (pin 2) of the One Shot in FIG. 1.

[0024] FIG. 4 is an Output Relay. The output of the One Shot momentarily powers pin 2 of the relay coil. The engine coil is interrupted be either opening or closing the coil's PWR, via the COM+N.C., or COM+N.O. relay connections.

[0025] FIG. 5 is the production circuit I have designed. It is a combination of FIGS. 2,3 and 4 except it has the power supply circuit. Hall pin 2 and Hall pin 3 refer to Hall sensor part no: AH276

SUMMARY

[0026] I Initially designed this circuit to retrofit existing systems, such as, used in expired U.S. Pat. No. 4,753,618 or any other system utilizing a micro switch to perform a shift interrupt but may also be used in new systems. With my solution a shift interrupt is implemented and triggered directly from a Hall Sensor and a One Shot Circuit. Specifically, it interrupts the engine coil when the position of the shift cable causes the hall sensor to detect a change in the direction and/or width of the magnetic fields. Meaning, the magnets move across the Hall sensor when shifting gears. The magnets are arranged in a particular pole arrangement. A transition of magnetic poles (North to South or South to North) causes the sensor to toggle it's output and latch. Once latched to a specific output, a transition to another direction toggles and latches to another output. This output toggle state is fed directly to trigger a mono stable multivibrator circuit that has an RC time circuit that controls the time length of the interrupt.