Transistor ignition system having a protective circuit

Claim 1

IN COMBINATION, AN INTERNAL COMBUSTION ENGINE, A PLURALITY OF SPARK PLUGS FOR SAID ENGINE, A SOURCE OF DIRECT CURRENT, AN IGNITION COIL HAVING A PRIMARY WINDING AND A SECONDARY WINDING, SPARK DISTRIBUTING MEANS DRIVEN BY SAID ENGINE CONNECTED WITH SAID SPARK PLUGS, MEANS CONNECTING SAID SECONDARY WINDING WITH SAID SPARK DISTRIBUTING MEANS, A TIMING DEVICE DRIVEN BY SAID ENGINE, A FIRST TRANSISTOR HAVING EMITTER, COLLECTOR AND BASE ELECTRODES, MEANS CONNECTING SAID PRIMARY WINDING AND THE EMITTER AND COLLECTOR ELECTRODES OF SAID FIRST TRANSISTOR ACROSS SAID SOURCE OF DIRECT CURRENT, MEANS CONNECTING THE BASE ELECTRODE OF SAID TRANSISTOR WITH SAID TIMING DEVICE, A SECOND TRANSISTOR, MEANS CONNECTING THE EMITTER OF SAID SECOND TRANSISTOR WITH THE EMITTER OF SAID FIRST TRANSISTOR, MEANS CONNECTING THE COLLECTOR OF SAID SECOND TRANSISTOR WITH THE COLLECTOR OF SAID FIRST TRANSISTOR, A VOLTAGE RESPONSIVE NETWORK CONNECTED ACROSS THE EMITTER AND COLLECTOR ELECTRODES OF SAID TRANSISTORS, AND MEANS CONNECTING A POINT ON SAID VOLTAGE RESPONSIVE NETWORK WITH SAID BASE ELECTRODE OF SAID SECOND TRANSISTOR, SAID VOLTAGE RESPONSIVE NETWORK INCLUDING MEANS FOR BIASING SAID SECOND TRANSISTOR CONDUCTIVE WHEN A VOLTAGE IS DEVELOPED ACROSS SAID EMITTER AND COLLECTOR ELECTRODES OF SAID FIRST TRANSISTOR AND ACROSS SAID NETWORK OF A PREDETERMINED MAGNITUDE AND OF A POLARITY TO CAUSE CURRENT TO FLOW THROUGH SAID FIRST TRANSISTOR IN A FORWARD DIRECTION.