Capacitor discharge ignition system having circuit means for controlling the spark advance

Claim 2

In a capacitor discharge ignition system for an internal combustion engine having generator means driven in synchronism with the engine for producing electrical pulses, and detector means responsive to the pulses reaching a given level to discharge the ignition capacitor to produce an ignition pulse for operating the engine, the generated pulses reaching the given level in a time relation to the engine r.p.m. to provide spark advance, the combination including, control circuit means connected to the detector means, first circuit means connected to said control circuit means for operating the same to a first condition for reducing the sensitivity of the detector means during the initial period from engine starting until the engine speed reaches a predetermined r.p.m. thereby maintaining a substantially constant means rate of spark advance during said period, and second circuit means connected to said control circuit means and being responsive to the engine speed exceeding said predetermined r.p.m. to operate said control circuit means to a second condition to render substantially full sensitivity to the detector means so the generated pulses reach the given level in a timed relation to the r.p.m. thereby providing spark advance.

Claim 3

The capacitor discharge ignition system of claim 1 wherein said control circuit means is an electron control device connected between the detector means and said first and second circuit means, said first and second circuit means each applying a bias potential to said electron control means in response to the engine r.p.m. to control the electron flow therethrough thereby controlling the sensitivity of the detector means.

Claim 4

The capacitor discharge ignition system of claim 1 wherein said control circuit means is a transistor having a control electrode, said transistor being connected between the detector means and a reference potential, said first circuit means comprising a first time base circuit including a capacitor connected to the control electrode of said transistor, said capacitor being charged in response to a potential during said initial period of engine operation to bias said transistor into conduction thereby shunting a portion of the generated pulses to reduce the sensitivity of the detector means, and said second circuit means comprising a second time base circuit including a second capacitor connected to the control electrode of said transistor, said second capacitor being charged at an engine r.p.m. greater than said predetermined r.p.m. to bias said control transistor out of conduction thereby returning substantially full sensitivity to the detector means.

Claim 5

A capacitor discharge ignition system for an internal combustion engine, including in combination, generator means driven in synchronism with the engine for producing electric pulses, level detector circuit means coupled to said generator means and being responsive to the generated pulses reaching a given level to discharge the ignition capacitor to produce an ignition pulse, saturable oscillator means coupled to the ignition capacitor for charging the same, said oscillator means comprising a transistor having control and output electrodes and a transformer having first and second inductively coupled windings, said output electrode of said transistor being coupled to said first winding, and circuit means for connecting said second winding to said control electrode of said transistor so that increased current in said first winding due to the conduction of sAid transistor induces current in said second winding to sustain conduction of said transistor into saturation, control circuit means connected to said level detector circuit means, and bias circuit means having first and second portions connected between said output transistor of said saturable oscillator means and said control circuit means, whereby conduction of said saturable oscillator means with initial operation of the engine energizes said first portion of said bias circuit means through said output transistor to bias said control circuit means to a first condition thereby shunting a portion of the generated pulses required to discharge the ignition capacitor to effectively maintain the spark advance constant during the initial operation of the engine, and said second portion of said bias circuit means being responsive to the conduction of said output transistor with the engine r.p.m. reaching a predetermined amount to bias said control circuit means to a second condition to provide spark advance relative to engine r.p.m.

Claim 6

A capacitor discharge ignition system for an internal combustion engine, including in combination, generator means driven in synchronism with the engine for producing electric pulses, level detector circuit means coupled to said generator means and being responsive to the generated pulses reaching a given level to discharge the ignition capacitor to produce an ignition pulse, saturable oscillator means coupled to the ignition capacitor for charging the same, said oscillator means comprising a transistor having control and output electrodes and a transformer having first and second inductively coupled windings, said output electrode of said transistor being coupled to said first winding, and circuit means for connecting said second winding to said control electrode of said transistor so that increased current in said first winding due to the conduction of sAid transistor induces current in said second winding to sustain conduction of said transistor into saturation, control circuit means connected to said level detector circuit means, and bias circuit means having first and second portions connected between said output transistor of said saturable oscillator means and said control circuit means, whereby conduction of said saturable oscillator means with initial operation of the engine energizes said first portion of said bias circuit means through said output transistor to bias said control circuit means to a first condition thereby shunting a portion of the generated pulses required to discharge the ignition capacitor to effectively maintain the spark advance constant during the initial operation of the engine, and said second portion of said bias circuit means being responsive to the conduction of said output transistor with the engine r.p.m. reaching a predetermined amount to bias said control circuit means to a second condition to provide spark advance relative to engine r.p.m.

Claim 7

The capacitor discharge ignition circuit of claim 4 wherein said level detector circuit means includes a silicon-controlled rectifier having a gate electrode, said generator means being connected between said gate electrode and a reference potential, said control circuit means includes a transistor having a control electrode and being connected between said gate electrode and a reference potential, and said first and second portions of said bias circuit means are connected to said control electrode, said first circuit portion acting to bias said transistor into conduction to shunt a portion of the generated pulses to the reference potential, and said second circuit portion of said bias circuit means acting to bias said transistor out of conduction.

Claim 8

The capacitor discharge ignition system of claim 5 wherein said first portion of said bias circuit means includes a rectifier and time base circuit means connected between said output transistor of said saturable oscillator and the control electrode of said control transistor, said rectifier coupling pulses of one polarity to said time base circuit means to charge the same to render said control transistor conductive, and said second portion of said bias circuit means includes a second rectifier and second time base circuit means connected between the output transistor of said saturable oscillator and the control electrode of said control transistor, said second rectifier coupling pulses of a polarity opposite said one polarity to said second time base circuit means to charge the same to render said control transistor nonconductive.

Claim 9

The capacitor discharge ignition system of claim 6 wherein said second time base circuit means has a greater time constant than said first time base circuit means.