초록 ▼

An improved capacitance bridge type liquid level control system for use in refrigeration applications is disclosed which provides improved apparatus for sealing the probe in its mounting and for insulating same against the condenser reservoir stand pipe in which it is mounted. Improved sealing betwe

An improved capacitance bridge type liquid level control system for use in refrigeration applications is disclosed which provides improved apparatus for sealing the probe in its mounting and for insulating same against the condenser reservoir stand pipe in which it is mounted. Improved sealing between the probe and probe body is accomplished through an annular PTFE seal which when compressed pushes inwardly to seal a tubular PTFE insulation against annular ridges in the side of the probe rod proper. The improved probe rod shape also maintains a proper stabilized axial alignment between the probe rod and the probe body. The invention also resides in improved circuitry for the capacitance bridge liquid level control system which includes a built-in simulation circuit for testing the apparatus, improved voltage feedback damping for providing a stable circuitry utilizing digital display, light emitting diodes, improved anti-splashing circuitry for stabilizing digital display read out, and a reversed lower differential function setting for enabling the low level adjustment set point to be set more accurately heretofore known.

대표청구항 ▼

In a probe for a capacitance bridge liquid level control system, said probe including: a generally cylindrical elongate steel rod having a pre-determined length, an electrical conductor of known resistance attached on one end of said elongate rod and operatively connectable to a signal amplifier cir

In a probe for a capacitance bridge liquid level control system, said probe including: a generally cylindrical elongate steel rod having a pre-determined length, an electrical conductor of known resistance attached on one end of said elongate rod and operatively connectable to a signal amplifier circuit, a tubular insulator surrounding said elongate steel rod, a generally tubular first probe body member having a bore therethrough through which said rod and tubular insulator are positioned, and at least a portion of said bore having a diameter sufficiently larger than a diameter of said tubular insulator to define an annular space between said body bore and said tubular insulator, a generally tubular second probe body member having a bore therethrough sized to closely fit around a portion of the outside of said tubular insulator and adapted for selective axial movement with respect to said bore on said tubular first probe body, and selectably engageable with said tubular first probe body, deformable tubular means fitting around said tubular insulator in said annular space between said bore on said first probe body member and said tubular insulator when said second probe body member is moved axially with respect to said first probe body member to compress said deformable tubular means axially causing a reaction radially to deform said insulator inward toward the cylindrical outer surface of said steel rod as a seal therebetween, and an improvement comprising: an annular indentation around and directly on said elongate steel rod at a position radially inwardly of said deformable tubular means for receiving a portion of said tubular insulator therein when said second probe body compresses said deformable tubular means to improve the sealing capabilities between said steel rod and said tubular insulator.