Patent ID: 6594129
Filing Date: 2003-07-15
Classification: H03K

Abstract:
A method of cutting off a circuit under an overcurrent in a semiconductor relay system for supplying a power source to a load, said method comprising the steps of:setting a first prescribed value which is a current value higher than a rated load current for the load and is a maximum current value supplied to the load; setting a second prescribed value which is a current value between said first prescribed value and said rated current value; sampling a current value flowing to the lamp load at predetermined intervals; comparing said sampled current value with said second prescribed value; controlling the current supplied to the load within a range between said first prescribed value and said second prescribed value in case of said sampled current higher than said first prescribed value flows to the load; and deciding said sampled current as an overcurrent and cutting off the semiconductor relay to stop the current supply to said load in case of said sampled current value higher than said second prescribed value is counted by a predetermined number of times.