Reduced parts count isolated AC current switching and sensing

An electrical appliance whose operation is energized by AC electrical power, the electrical appliance comprising:

• a. a load that receives AC electrical power;
• and
• b. a control and sensing circuit for selectively supplying AC electrical power to the load, the control and sensing circuit including:
• i. a relay that includes:
• A. at least one set of contacts that are connectable in series between a source of AC electrical power and the load;
• and
• B. an electromagnet that includes a coil of insulated wire which upon supplying an electrical current to the coil changes the set of contacts between:
• I. a closed state in which the load receives AC electrical power;
• and
• II. an open state in which the load does not receive AC electrical power,
• the load and the set of contacts being connected in series so electrical current flows therethrough from the source of AC electrical power only exterior to the coil of said electromagnet;
• ii. a coil energizing switch connected in series with the coil and with a source of relay energizing electrical power which coil energizing switch:
• A. in a first state does not supply electrical current to the coil;
• and
• B. in a second state supplies electrical current to the coil for changing the set of contacts between the open state and the closed state;
• and
• iii. an AC voltage sensing circuit coupled to the coil for measuring an AC voltage induced in the coil by AC electrical current that flows only exterior to the coil of said electromagnet through the set of contacts and the load when the set of contacts are in the closed state in which the load receives AC electrical power from the source thereof.

A method for selectively supplying AC electrical power to a load, the method comprising the steps of:

• a. supplying AC electrical current to the load through at least one set of contacts of a relay, the set of contacts being connectable in series between a source of AC electrical power and the load, the relay also including an electromagnet that includes a coil of insulated wire which upon receiving an electrical current changes the set of contacts between:
• i. a closed state in which the load receives AC electrical power;
• and
• ii. an open state in which the load does not receive AC electrical power,
• the load and the set of contacts being connectable in series so electrical current flows therethrough from the source of AC electrical power only exterior to the coil of said electromagnet;
• b. supplying electrical current to the coil of the relay via a coil energizing switch connected in series with the coil and with a source of relay energizing electrical power, the coil energizing switch being operable:
• i. in a first state in which the coil does not receive electrical current;
• and
• ii. in a second state in which the coil receives electrical current for changing the set of contacts between the open state and the closed state;
• and
• c. measuring an AC voltage induced in the coil by AC electrical current that flows only exterior to the coil of said electromagnet through the set of contacts and the load when the set of contacts are in the closed state in which the load receives AC electrical power from the source thereof.