Ignition and control system for gas burners

Claim 1

In a burner control system, a burner, a biased closed solenoid fuel supply valve including a winding, an electrical power source, a glow igniter, circuit connections including a double-throw, snap-acting, temperature responsive switch in its cold position connecting said igniter across said power source, circuit connections including said double-throw switch in its hot position and a normally open switch when closed connecting said winding across said power source to effect opening of said valve, switch actuating means connected in series with said igniter and operative in response to current flow through said igniter to close said normally open switch, said double-throw switch being responsive to radiant energy of the igniter at gas ignition temperature to snap from its cold to hot position, thereby to deenergize said igniter and switch actuating means and to energize said valve winding substantially simultaneously, said igniter having sufficient mass to retain a gas ignition temperature long enough after de-energization to ignite fuel at said burner, said switch actuating means being responsive to current flow through said igniter to close said biased open switch before said igniter reaches gas ignition temperature and having sufficient lag after de-energization to retain said switch closed until said fuel valve is opened, said double-throw switch being further responsive to flame at said burner to remain in its hot position, and circuit means including said double-throw switch in its hot position connecting said winding across said power source for a limited energization thereof sufficient to hold said valve open but insufficient to pull the valve open from its biased closed position.