Patent ID: 7684163

Claim:
An abnormal connection detecting circuit for detecting an abnormal connection status of a load, the abnormal connection detecting circuit comprising: a first transistor configured to receive a predetermined first bias voltage at a first control electrode, and output a first current according to a voltage of a second connection terminal connected to a drain of the first; and an abnormality detector configured to detect the first current output from the first transistor, and detect the abnormal connection status based on the detected first current, the abnormal connection status being an open status in which the load is not connected to both the second connection terminal and a first connection terminal to which a predetermined positive source voltage is applied, the load being connected between said first connection terminal and said second connection terminal, or a short-circuit status in which the second connection terminal is short-circuited to the negative source voltage of the second connection terminal, wherein said abnormality detector and said first transistor are connected in series between said first connection terminal and said second connection terminal, with said abnormally detector being connected to said first connection terminal and to said first transistor, and said first transistor being connected to said abnormally detector and said second connection terminal.