Electrical transmission or interconnection systems – Switching systems – Condition responsive
Patent
1993-05-14
1995-08-22
Pellinen, A. D.
Electrical transmission or interconnection systems
Switching systems
Condition responsive
326 62, H03K 190175
Patent
active
054443091
ABSTRACT:
A controller such as a programmable logic controller (PLC) is coupled to a load such as a contactor or motor starter through an interface that operates over a range of DC or AC voltage and couples a Start output of the controller to the load through a low current switch such as an opto-relay. The interface has a charging circuit coupled to the controller output, with a switching transistor, a load resistor and a capacitor in series. The low current switch is operated from accumulated charge in the capacitor and couples power to the load device. Charging of the capacitor to a threshold switches off of the transistor for an interval timed by a one-shot, during which the low current switch remains activated due to current draining from the capacitor. In an AC embodiment with a triac controller output, the capacitor continues to power the low current switch for the remainder of the positive AC half cycle, regardless of the triac, which may cease conduction due to lack of sufficient loading. The circuit substantially reduces the current dissipation of an interface between a PLC and a motor starter or contactor. The interface can include optically isolated signalling in both directions, including feed back of contact status and trip indications to inputs of the PLC.
REFERENCES:
patent: 4263521 (1981-04-01), Senger
patent: 5192874 (1993-03-01), Adams
Hurley Rick A.
Innes Mark E.
Eaton Corporation
Kaplan Jonathan
Moran Martin J.
Pellinen A. D.
LandOfFree
Reduced wattage PLC interface does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Reduced wattage PLC interface, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reduced wattage PLC interface will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2143828