| 摘要 |
PROBLEM TO BE SOLVED: To achieve overcurrent protection of a switching element by a new technique.SOLUTION: An electric load driving device 1 includes: a first terminal 7 and a second terminal 9 to which respective end parts of an electric load 3 are connected; a first current detecting resistor 11 connected in series to a first current path between the low potential side VG of a power supply 5 and the first terminal 7; a switching element 13 connected in series to a second current path between the high potential side VB of the power supply 5 and the second terminal 9; and control means 37 which when a voltage expressing a voltage difference between both ends of the resistor 11 is inputted to an input part 19 as an input voltage Vm and [Vm≥upper side threshold voltage] is detected, turns off the switching element 13, and when [Vm≤lower side threshold voltage] is detected, turns on the switching element 13. In the device 1, a second current detecting resistor 15 is connected in series to the second current path, and when the voltage difference between both ends of the resistor 15 becomes a predetermined value or more, input voltage change means 39 changes the input voltage Vm to the input part 19 to a predetermined voltage Vcc (>upper side threshold voltage). |
