Paralleling Mechanical Relays for Increased Current Carrying and Switching Capacity
AssigneeAstronics Advanced Electronic Systems Corp.
InventorsFrederick J. Potter, Massoud Vaziri, Patrick Wellington Mills
Life of this patent
Estimating the term…
Abstract
Multiple relays are connected in parallel by including one or more semiconductor devices connected across the relay contacts. The semiconductor devices are triggered to conduct and shunt transient currents during the opening and closing of the relay contacts to protect the relay contacts from overcurrent and to eliminate arcing during relay switching. This permits a combination of smaller relays to replace a larger and more expensive relay in applications that require switching of large load currents.
Claims15
A relay system for switching current to a load comprising:
- a plurality of relays arranged in an electrically parallel configuration, each relay sized to carry a portion of the current to the load;
- and
- a semiconductor switch assembly connected across the plurality of relays configured to protect each of the relays from passing excess current during a transient time period when their contacts are opening or closing.
A virtual circuit breaker comprising:
- a plurality of relays arranged in an electrically parallel configuration, each relay sized to carry a portion of current to a load;
- a semiconductor switch assembly connected across the plurality of relays configured to protect each of the relays from passing excess current during a transient time period when their contacts are opening or closing;
- and
- a control circuit for monitoring current to said load and opening said relay contacts when an over current or short circuit condition is sensed.
A method for reducing contact failure when a plurality of relays, each having one or more contacts, are arranged in an electrically parallel configuration to switch current to a load, comprising the steps of:
- connecting a semiconductor switch assembly across said plurality of relays, and
- energizing said semiconductor switch assembly to shunt excess current away from the relay contacts during a transient time period when their contacts are opening or closing.
Dependencies are inferred from the claim text.