Ac controlled relay drive circuit
AssigneeThe Vollrath Company, L.L.C.
InventorDonald Zahrte, SR.
Life of this patent
Estimating the term…
Abstract
A drive circuit includes a voltage input circuit, a first surge protection device, and a second surge protection device. The voltage input circuit includes a first line terminal and a second line terminal, and supplies an input voltage to the first and second line terminals. The first surge protection device is connected between the first line terminal and ground to connect the first line terminal to ground when the input voltage is supplied, and to disconnect the first line terminal from ground when the input voltage is not supplied. The second surge protection device is connected between the second line terminal and ground to connect the second line terminal to ground when the input voltage is supplied, and to disconnect the second line terminal from ground when the input voltage is not supplied.
Claims20
A drive circuit comprising:
- a voltage input circuit comprising a first line terminal and a second line terminal, the voltage input circuit configured to supply an input voltage to the first and second line terminals;
- a first surge suppression device coupled between the first line terminal and ground, the first surge protection device configured to connect the first line terminal to ground when the input voltage is supplied, and to disconnect the first line terminal from ground when the input voltage is not supplied;
- and
- a second surge protection device coupled between the second line terminal and ground, the second surge protection device configured to connect the second line terminal to ground when the input voltage is supplied, and to disconnect the second line terminal from ground when the input voltage is not supplied.
An appliance comprising:
- a load;
- and
- a surge protection circuit connected to the load, the surge protection circuit comprising:
- a voltage input circuit comprising a first line terminal and a second line terminal, the voltage input circuit configured to supply an input voltage to the first and second line terminals;
- a first surge protection device coupled between the first line terminal and ground, the first surge protection device configured to connect the first line terminal to ground when the input voltage is supplied, and to disconnect the first line terminal from ground when the input voltage is not supplied;
- and
- a second surge protection device coupled between the second line terminal and ground, the second surge protection device configured to connect the second line terminal to ground when the input voltage is supplied, and to disconnect the second line terminal from ground when the input voltage is not supplied.
A method for isolating one or more varistors in a surge protection circuit, the method comprising:
- providing a surge protection circuit, the surge protection circuit comprising:
- a voltage input circuit comprising a first line terminal and a second line terminal, the voltage input circuit configured to supply an input voltage to the first and second line terminals;
- a first varistor coupled between the first line terminal and ground to provide an electrical path from the first line terminal to ground;
- a second varistor coupled between the second line terminal and ground to provide an electrical path from the second line terminal to ground;
- and
- a switch connected between the first and second line terminals and ground, the switch configured to connect each of the first and second varistors from ground when the switch is in a closed state, and to isolate each of the first and second varistors from ground when the switch is in an open state;
- connecting a load to the surge protection circuit;
- applying a hi-pot voltage on the load;
- and
- controlling, by the surge protection circuit, the switch to be in the open state to isolate each of the first and second varistors from ground in response to the high voltage.
Dependencies are inferred from the claim text.