Patent attributes
A drive circuit is provided for controlling a solenoid valve having a solenoid coil. The drive circuit includes a first semiconductor device, a flyback circuit, and a processor. The first semiconductor is coupled in series with the coil and is controlled by a gate signal to energize the coil. The flyback circuit is in parallel with the coil and includes a series-coupled second semiconductor device and a diode. The second semiconductor is controlled by a flyback control signal to enable the flyback circuit when the first semiconductor is controlled by the gate signal to hold the valve open. The diode has a low forward voltage to slow decay of a current conducted through the coil. The processor generates the gate signal to control the first semiconductor and to reduce a duty cycle of the gate signal when the flyback circuit is enabled to reduce power consumption by the coil.
