Electromagnetic valve drive device

An electromagnetic valve drive device which applies a drive voltage to an electromagnetic coil of an electromagnetic valve to supply a drive current to the electromagnetic coil, comprising:

• a power supplier which intermittently applies a hold voltage as the drive voltage to the electromagnetic coil to supply a hold current as the drive current to the electromagnetic coil;
• a detector which calculates a detected current indicating a magnitude of the drive current;
• a first comparator which compares a hold detected current as the detected current calculated by the detector with a first threshold value that is a predetermined value greater than zero, the hold detected current indicating a magnitude of the hold current;
• a filter which performs integration processing on an output of the first comparator;
• a second comparator which compares an output of the filter with a second threshold value that is a predetermined value greater than zero to generate an output signal used for generating a control signal for controlling the power supplier;
• and
• a control signal generator which generates the control signal for controlling the power supplier based on the output signal of the second comparator,
• wherein the filter is a count-up/down type digital filter,
• the power supplier supplies the hold current to the electromagnetic coil after the detected current increases to reach a predetermined current peak value, and
• the power supplier supplies the hold current to the electromagnetic coil such that the hold detected current fluctuates between a prescribed maximum value and a prescribed minimum value that are lower than the current peak value, greater than zero and different from each other.