| 摘要 |
PURPOSE:To sufficiently reduce the rise-up time of an electric current for driving a valve, by connecting in parallel to a current limiting resistor, which constitutes a series circuit with an injection valve and a switching element, the second switching element and driving this element to be turned on only for a predetermined time. CONSTITUTION:If an injection pulse signal IP is applied to a transistor T1, pulse signals IP1, IP2 appearing by inverting the signal IP are generated in a collector side of the transistor T1. And the pulse signal IP2 turns on a transistor T2 allowing a driving current fo flow in an injection valve SOL. WHile a monostable multivibrator MM, being a pulse generating circuit, is triggered by a rise-up of the pulse signal IP1, generating a pulse signal Pm. This signal Pm turns on a transistor T3, being the second switching element, allowing the driving current to flow in the transistor T3 for a fixed time immediately after the injection valve SOL is started to be driven. On the other hand, if the fixed time passes, the valve driving current is allowed to flow through a resistor R1. |
