초록 ▼

A condition responsive apparatus is provided including a pressure gauge having a Bourdon tube expandable in response to an external pressure. In the preferred embodiment, an optical coupler, including a solid state light source and a detector, is mounted in proximity to a vane attached to the Bourdo

A condition responsive apparatus is provided including a pressure gauge having a Bourdon tube expandable in response to an external pressure. In the preferred embodiment, an optical coupler, including a solid state light source and a detector, is mounted in proximity to a vane attached to the Bourdon tube. As the Bourdon tube flexes with increased pressure, the vane passes between the light source and the detector, thus blocking the radiation from the light source. The detector includes a Darlington amplifier which forms part of a voltage divider network for connecting an output signal from the Darlington amplifier to a pulse generating circuit. In operation, when the vane connected to the Bourdon tube passes between the light source and the detector, the pulse generating circuit responds to an increased voltage across the output of the voltage divider and is thus triggered to turn on a control transistor. The control transistor serves to turn on a power transistor for controlling an alarm or other control element.

대표청구항 ▼

A condition responsive apparatus, comprising: a pressure gauge having a Bourdon tube expandable in response to an external pressure and including an indicator responsive to the expansion of the Bourdon tube; an optical coupler including a light emitting diode and a Darlington amplifier detector, sai

A condition responsive apparatus, comprising: a pressure gauge having a Bourdon tube expandable in response to an external pressure and including an indicator responsive to the expansion of the Bourdon tube; an optical coupler including a light emitting diode and a Darlington amplifier detector, said Darlington amplifier detector including an input photo transistor and an output driver transistor; a vane attached to said Bourdon tube for movement therewith between said light emitting diode and said photo transistor from a first position to a second position in response to a change in external pressure; a Schmitt trigger circuit having an input connected to a voltage node for receiving a drive voltage and in response thereto generating a control signal, said voltage node being further connected to the output driver transistor; a coupling circuit connected to the output driver transistor of said Darlington amplifier detector and in response to movement of said vane from the first position to the second position generating the drive voltage above a threshold level to said Schmitt trigger circuit, said Schmitt trigger circuit generating the control signal in response to the drive voltage above the threshold level; control means connected to said Schmitt trigger circuit and in response to the control signal generating an output signal; and power means connected to said control means for applying the output signal to a load.