Control circuit for an electric door strike using a latching solenoid

A control circuit for a latching solenoid, said control circuit comprising:

• a dc voltage source;
• an on/off switch;
• a diode;
• a capacitor;
• connecting means for making connection to the coil of a latching solenoid;
• and
• a single pole double throw relay having a coil, a normally closed terminal, a normally open terminal and a common terminal, said relay making contact between said normally closed terminal and said common terminal when said coil of said relay is deenergized and said relay making contact between said normally open and said common terminal when said coil of said relay is energized;
• whereby:
• when said on/off switch is closed said voltage source is connected across said coil of said relay energizing said coil of said relay causing said relay to make contact between said normally open terminal and said common terminal causing said closed on/off switch, said diode, said capacitor and said connecting means to be serially connected across said voltage source;
• and
• when said on/off switch is subsequently opened, disconnecting said voltage source from said coil of said relay, or when said voltage source fails, said coil of said relay is deenergized and contact is made between said normally closed terminal and said common terminal, causing said connector means to be connected across said capacitor.