Patent ID: 8553377

Claim:
An electronic control device, comprising: a first switching element for driving a load, connected in series with the load between a power source and ground; a second switching element for taking ON/OFF control of the first switching element, connected to the control terminal of the first switching element; a pulse generator for controlling the second switching element; and a control circuit including a trigger circuit having a capacitor connected between the pulse generator and the control terminal of the second switching element and a first resistor connected in series to the capacitor, and a latch circuit comprising a second resistor and a diode connected in series, wherein the latch circuit is connected via the diode, between a first junction that is a connecting point of the load with the first switching element and the control terminal of the second switching element; wherein when the pulse generator outputs a drive signal, the control circuit turns on through the trigger circuit the second switching element for a predetermined time, thereby also turning on the first switching element so as to drive the load, and in addition, holds the second switching element in an ON state through the latch circuit by a voltage generated at the first junction, whereas when the pulse generator stops outputting the drive signal, the control circuit turns off both of the first switching element and the second switching element; meanwhile if the load is short-circuited, the control circuit turns off the second switching element through the latch circuit by the voltage generated at the first junction even when the pulse generator is outputting the drive signal, thereby also turning off the first switching element.