Constant current relay drive circuit

A relay drive circuit for driving a relay having a relay contact, the relay drive circuit comprising:

• a power supply circuit for producing a constant voltage from a power supply;
• an initial energization circuit for performing an initial energization such that the power supply provides an initial energizing voltage to the relay to drive the relay contact to a closed position;
• a holding energization circuit for performing a holding energization such that the constant voltage provides a constant current to the relay to hold the relay contact in the closed position;
• and
• a control circuit for controlling the initial energization circuit and the holding energization circuit, wherein
• the control circuit controls the initial energization circuit in such a manner that the initial energization circuit performs the initial energization for a predetermined time period when the relay is driven, and
• the control circuit controls the holding energization circuit in such a manner that the holding energization circuit performs the holding energization as long as the relay is driven.

A relay drive circuit for driving a relay having a relay contact, the relay drive circuit comprising:

• a power supply circuit for producing a constant voltage from a power supply;
• an initial energization circuit for performing an initial energization such that the power supply voltage provides an initial energizing voltage to the relay to drive the relay contact to a closed position;
• a holding energization circuit for performing a holding energization such that the constant voltage provides a constant current to the relay to hold the relay contact in the closed position;
• a power supply switching circuit for switching between the power supply and the constant voltage;
• and
• a control circuit for controlling the initial energization circuit, the holding energization circuit, and the power supply switching circuit, wherein
• the control circuit controls the power supply switching circuit in such a manner that the power supply is selected when the initial energization is performed and the constant voltage is selected when the holding energization is performed, and
• the control circuit controls the initial energization circuit in such a manner that when the relay is driven, the initial energization circuit performs the initial energization for the predetermined time period and the holding energization circuit performs the holding energization after the predetermined time period.

A relay drive method comprising:

• providing an energizing voltage to a relay for a predetermined time period when a relay is driven;
• stopping the energizing voltage after the relay is fully operated;
• generating a constant voltage lower than a voltage of a power supply;
• and
• providing a constant current from the constant voltage to hold an operation of the relay.