| 摘要 |
PURPOSE:To enable a different current to be detected with one detection circuit by a method wherein the title excess current detection device is composed of a resistor and a diode which make one detection current flow and an A/D converter which detects the current having flowed to the resistor and the diode. CONSTITUTION:A resistor 5 and a diode 15 which make a detection current flow are connected to a drive circuit 7 of a coil 6. At that time a voltage value to be inputted to an A/D converter 3 is different according to a state of the drive circuit 7 and becomes a specific value at each ON/OFF state. A switching means 4 is generally of an ON state in a printing control state of a printer, which connects a power source to the drive circuit. The voltage value obtained from the A/D converter 3 is converted to a current by a current judge means 1 to detect an overcurrent. That is, the current judge means 1 calculates a voltage value to be inputted to the A/D converter 3, and compares the calculated value with the voltage value inputted actually to the A/D converter 3. Where they do not come to be almost the same value, the drive circuit 7 is judged to be abnormal. |
