摘要:
The present invention teaches a dimmer which incorporates an alternating current (AC) trigger which exhibits asymmetrical electrical characteristics. This eliminates the undesirable snap on hysteresis effect associated with conventional dimmers utilizing symmetrical AC triggers such as diacs and silicon bilateral switches (SBS). One embodiment of the present invention utilizes a zener diode to create the asymmetry. During one polarity of the AC source, the breakover voltage of the trigger is increased, forcing the trigger to breakover at a time later in the AC cycle than it would otherwise have with a symmetric trigger. This compensates for charge dumping of the phase control capacitor into the gate of the triac which would otherwise cause the snap on hysteresis effect.
摘要:
In the present invention the basic detection and interruption components of an Immersion Detection Circuit Interrupter (IDCI), in combination with the line, neutral and shield conductors of an extension or appliance cord provides a new improved type of detector, a Leakage Current Detector Interrupter (LCDI) which interrupts current to a load when current leakage is detected between the line or neutral conductors of the cord and the shield conductor. The new improved LCDI detector provides, either singularly or in combination, the following advantages: Prevents the LCDI from being reset should the device become inoperative (reset lockout); Provides an indication of the integrity of the shield in the extension or appliance cord; Tests the integrity of the shield within the extension or appliance cord, in addition to testing the functionality of the LCDI; Interrupts current to the load if an electrical connection is detected between the shield and neutral, or the shield and ground, in addition to the existing detection of leakage current from the phase conductor; Allows the LCDI to trip during an open neutral condition by utilizing the ground connection as a return wire for the trip coil; and/or Provides immersion detection at the receptacle end of the extension cord in addition to protection from leakage faults.
摘要:
The present invention teaches a dimmer which incorporates an alternating current (AC) trigger which exhibits asymmetrical electrical characteristics. This eliminates the undesirable snap on hysteresis effect associated with conventional dimmers utilizing symmetrical AC triggers such as diacs and silicon bilateral switches (SBS). One embodiment of the present invention utilizes a zener diode to create the asymmetry. During one polarity of the AC source, the breakover voltage of the trigger is increased, forcing the trigger to breakover at a time later in the AC cycle than it would otherwise have with a symmetric trigger. This compensates for charge dumping of the phase control capacitor into the gate of the triac which would otherwise cause the snap on hysteresis effect.
摘要:
A resettable circuit interrupting device such as a GFCI that, when reverse wired during installation, will trip and prevent power being applied to the load side of the GFCI when powered up. A current limiting circuit is connected between the phase and a ground terminal on the line side of the differential transformer of the GFCI. When the GFCI is connected correctly, the current through the current limiting circuit will have no significant effect on the GFCI, and it will operate normally. When, however, the line conductors are connected to the load terminals of the GFCI and the load conductors are connected to the line terminals of the GFCI, the current through the current limiting circuit will appear as a ground fault and cause the GFCI to trip.
摘要:
A string of miniature holiday lamps connected in a series circuit with each lamp having an indicating device connected in parallel to its respective lamp. The indicating device is operated in response to the non functioning of the lamp with which it is connected in parallel. When the lamp fails, the full line voltage of the series circuit passes through the indicating device causing it to activate, signaling the non functioning lamp. The signaling device can be a resistor associated with a thermochromic paint that changes color when activated by the heat from the resistor, a sound alarm, an odor activated device or an electroluminescent light. In another embodiment the signaling device can be used to indicate a circuit having a resistive load is energized.