Signal isolating and sampling circuit
AssigneeHoneywell Inc.
InventorsTadashi Sonobe, Seiji Onoki
Life of this patent
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Abstract
A signal isolating and sampling circuit using a transformer to isolate a signal input circuit from a signal output circuit. Signal sampling switches are used in the input and output circuits to sample an input signal applied to the input circuit. A photocoupler is provided for coupling a switch selecting signal to the sampling switch in the input circuit while an energizing signal for driving the sampling switch in the input circuit is supplied through the transformer from an energizing signal source connected to the signal output circuit. The energizing signal is rectified in the signal input circuit and used to drive the signal input circuit sampling switch under control of the switch selecting signal.
Claims5
A signal isolating and sampling circuit comprising
- an input terminal
- an output terminal,
- a transformer means having primary and secondary sides,
- an input circuit sampling switch means connected between said primary of said transformer means and said input terminal,
- an output circuit sampling switch means connected between said secondary of said transformer means and said output terminal,
- a supply source switch means,
- a pulse supply means for supplying a switch energizing pulse to the secondary side of said transformer means through said supply source switch,
- a rectifying circuit means connected to the primary side of said transformer means for rectifying and storing said energizing pulse induced on said primary side of said transformer means,
- a photocoupler circuit means having an input and having an output connecting said input circuit sampling switch means to said rectifying circuit means and
- control means for connecting said input of said photocoupler means to a source of a switch selecting control signal for periodically driving said photocoupler circuit means to apply the stored energizing pulse to said input circuit sampling switch means whereby said input circuit sampling switch means is driven by the stored energizing pulse from said rectifying circuit means to connect said input terminal to said primary side of said transformer means and to apply a switch control signal to said supply source switch means to operate said supply source switch means to connect said pulse supply means to said secondary side of said transformer means between the driving of said photocoupler circuit by said switch selecting control signal,
Dependencies are inferred from the claim text.