Reverse-engineered direct spark ignition board from an oven
The direct spark ignition (DSI) board is responsible for opening the gas valve in an oven, igniting the gas, and ensuring that the valve closes if the flame goes out. I removed the DSI board shown below from an oven that failed and reverse engineered it. In this article, I will present its schematic and describe its operation. Operation The DSI receives three signals, BAKE_IN, BROIL_IN, and STOVE_IN. STOVE_IN connects to the live input through the four switches in the stove knobs. Whenever one of the switches is closed, 120VAC is connected to the STOVE_IN input, and the DSI ignites all four stove burners (although gas is not flowing to all of them). When the user selects the BAKE option, a relay on the oven's main board connects 120VAC to the BAKE_IN input, and the DSI board switches on the gas to the BAKE burner in the oven and tries to ignite it. If it determines that there is no flame, the gas valve is turned off immediately. Similarly, when the user selects the BROIL option