Coil Overheating Protection Circuit
Original Publication Date: 1986-Mar-01
Included in the Prior Art Database: 2005-Mar-08
Using the coil itself as a sensor to sense its own temperature, by monitoring the change of resistance as a function of temperature, permits the convenient detection of coil overheating in print actuators. The inductance of the coil is compensated by a delay, and a comparator provides the standard for determining the overheat condition. Coil overheating, due to the high usage of a print actuator at high speed, degrades printing quality and may damage the coil. A coil temperature-detecting device senses the temperature of the coil and gives a warning to the control unit to take action, either to slow down or to stop the printing for a period of time.