Switching control apparatus for electromagnetic control units

In a system employing an electromagnetic control unit, the control unit having an excitation winding, an apparatus for reliably switching the control unit between an open and closed condition, the improvement in the apparatus comprising:

• (a) an electrical switch connected in series with the excitation winding, said electrical switch having an actuating signal applied thereto;
• (b) timing means connected to the electrical switch and responsive to operating parameters of the system for controlling the actuating signal applied to the electrical switch;
• and
• (c) energy storing means for supplying, in dependence on said operating parameters, an auxiliary signal directly to the excitation winding for switching the control unit to its open condition,
• said energy storing means comprising a series circuit connected in parallel with the excitation winding, said series circuit including a capacitor and a resistor connected in series with the capacitor, and wherein a positive voltage is maintained at the junction between the capacitor and the resistor of the series circuit when the auxiliary signal is supplied to the excitation winding.

In a system employing an electromagnetic control unit, the control unit having an excitation winding, an apparatus for reliably switching the control unit between an open and closed condition, the improvement in the apparatus comprising:

• (a) an electrical switch connected in series with the excitation winding, said electrical switch having an actuating signal applied thereto;
• (b) timing means connected to the electrical switch and responsive to operating parameters of the system for controlling the actuating signal applied to the electrical switch;
• and
• (c) energy storing means for supplying, at a predetermined instant and in dependence on said operating parameters, an auxiliary signal directly to the excitation winding for switching the control unit to its open condition,
• said energy storing means comprising a series circuit connected in parallel with the excitation including a capacitor and a resistor connected in series with the capacitor, and wherein a positive voltage is maintained at the junction between the capacitor and the resistor of the series circuit when the auxiliary signal is supplied to the excitation winding.

In an apparatus for switching an electromagnetic valve employed with an internal combustion engine, between an open and closed condition, the improvement comprising:

• (a) an electrical switch connected in series with the excitation winding, said electrical switch having an actuating signal applied thereto;
• (b) timing means connected to the electrical switch and responsive to engine speed and engine manifold pressure for controlling the actuating signal applied to the electrical switch for opening and closing said switch, such that the electrical switch is closed when a predetermined engine speed and manifold pressure exist and subsequently opened at a predetermined time thereafter;
• and
• (c) energy storing means connected to the excitation winding and the timing means for supplying, when the electrical switch has been subsequently opened, an auxiliary signal directly to the excitation winding for switching the electromagnetic valve to its open condition,
• said energy storing means comprising a series circuit connected in parallel with the excitation winding, said series circuit including a capacitor and a resistor in series with the capacitor, and wherein a positive voltage is maintained at the junction between the capacitor and the resistor of the series circuit when the auxiliary signal is supplied to the excitation winding.