US3558857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature control system using a nonreentrant temperature-sensitive bridge transducer
Assignee: ADAMSON CO
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Filing: 1968-12-18
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Granted: 1971-01-26
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Expires: 1988-12-18
Abstract
Abstract A wheatstone bridge element including temperature-sensitive resistors is placed in or adjacent to a fluid which is to be temperature controlled and is energized at its input nodes. A diode and light source or a diode and an amplifier for driving a light source are connected across the output nodes of the bridge. A high-current triac is triggered by the charging of an RC circuit in which a resistive element is photocontrolled by the light source. Power control by the triac is used to control heating the fluid.
Inventors
- 👤 Warren L Braun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:20
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/1927; G05D23/1928; G05D23/193; G05D23/1931
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
158 words
A temperature measuring device comprising: a. a wheatstone bridge further comprising; 1. two input nodes, 2. two output nodes, and 3. for four impedance legs each connected between a different pair of one input and one output and one output node, b. at least one of a said impedance legs including an element having an impedance which varies significantly as a function of the temperature of the element; c. means for applying electrical power to said input nodes, and d. a series-connected diode and light source directly connected between the output nodes of said bridge, said diode being in a conducting state when said bridge is unbalanced in one direction and in a nonconducting state when said bridge is unbalanced in the other direction, whereby said light source means emits light as a function of the degree of unbalance of said bridge in one direction and emits no light when the bridge is unbalanced in the other direction.
Claim 2
Dependent Claim
158 words
A temperature measuring device comprising: a. a wheatstone bridge further comprising; 1. two input nodes, 2. two output nodes, and 3. for four impedance legs each connected between a different pair of one input and one output and one output node, b. at least one of a said impedance legs including an element having an impedance which varies significantly as a function of the temperature of the element; c. means for applying electrical power to said input nodes, and d. a series-connected diode and light source directly connected between the output nodes of said bridge, said diode being in a conducting state when said bridge is unbalanced in one direction and in a nonconducting state when said bridge is unbalanced in the other direction, whereby said light source means emits light as a function of the degree of unbalance of said bridge in one direction and emits no light when the bridge is unbalanced in the other direction.
Claim 3
Dependent Claim
4 words
two output nodes, and
Claim 4
Dependent Claim
4 words
two output nodes, and
Claim 5
Dependent Claim
71 words
a capacitor adapted to be charged through said photosensitive resistor at a rate controlled by the amount of light irradiated onto said photosensitive resistor, b. output means for changing the temperature of said fluid; c. supply means for supplying energy for operating said output means; and d. control means responsive to the charge on said capacitor for controlling the rate of energy transfer from said supply means to said output means.
Claim 6
Dependent Claim
71 words
a capacitor adapted to be charged through said photosensitive resistor at a rate controlled by the amount of light irradiated onto said photosensitive resistor, b. output means for changing the temperature of said fluid; c. supply means for supplying energy for operating said output means; and d. control means responsive to the charge on said capacitor for controlling the rate of energy transfer from said supply means to said output means.
Claim 7
Dependent Claim
13 words
A device according to claim 1 wherein said electrical power is AC power.
Claim 8
Dependent Claim
4 words
two output nodes, and
Claim 9
Dependent Claim
4 words
two output nodes, and
Claim 10
Dependent Claim
57 words
and an additional capacitor adapted to be Charged through said additional photosensitive resistor at a rate controlled by the amount of light irradiated onto said additional photosensitive resistor, and c. an additional control means responsive to the charge on said capacitor for controlling the rate of energy transfer from said additional supply means to said output means.
Claim 11
Dependent Claim
57 words
and an additional capacitor adapted to be Charged through said additional photosensitive resistor at a rate controlled by the amount of light irradiated onto said additional photosensitive resistor, and c. an additional control means responsive to the charge on said capacitor for controlling the rate of energy transfer from said additional supply means to said output means.
Claim 12
Dependent Claim
84 words
means connected between said supply means and said output means for receiving each half-cycle of said AC voltage, for blocking passage of said AC current from the beginning of said half-cycle until the occurrence of said output pulse, and for passing said AC current from the occurrence of said output pulse until the end of said half-cycle, whereby the amount of energy reaching said output means varies as a function of the relative phase difference between said pulse and said beginning of said half-cycle.
Claim 13
Dependent Claim
84 words
means connected between said supply means and said output means for receiving each half-cycle of said AC voltage, for blocking passage of said AC current from the beginning of said half-cycle until the occurrence of said output pulse, and for passing said AC current from the occurrence of said output pulse until the end of said half-cycle, whereby the amount of energy reaching said output means varies as a function of the relative phase difference between said pulse and said beginning of said half-cycle.
Claim 14
Dependent Claim
102 words
four impedance legs, each connected between a different pair of one input and one output node, b. at least one of said impedance legs including an element having an impedance which varies as a function of the temperature of the element; c. means for applying electrical power to said input nodes; d. a series-connected diode and variable resistance means directly connected across said output nodes; e. a transistor amplifier including a control conductor and at least one signal conductor, said control conductor connected to an output terminal of said variable resistance means; and f. a light source connected to said signal conductor.
Claim 15
Dependent Claim
102 words
four impedance legs, each connected between a different pair of one input and one output node, b. at least one of said impedance legs including an element having an impedance which varies as a function of the temperature of the element; c. means for applying electrical power to said input nodes; d. a series-connected diode and variable resistance means directly connected across said output nodes; e. a transistor amplifier including a control conductor and at least one signal conductor, said control conductor connected to an output terminal of said variable resistance means; and f. a light source connected to said signal conductor.
Claim 16
Dependent Claim
137 words
for four impedance legs each connected between a different pair of one input and one output and one output node, b. at least one of a said impedance legs including an element having an impedance which varies significantly as a function of the temperature of the element; c. means for applying electrical power to said input nodes, and d. a series-connected diode and light source directly connected between the output nodes of said bridge, said diode being in a conducting state when said bridge is unbalanced in one direction and in a nonconducting state when said bridge is unbalanced in the other direction, whereby said light source means emits light as a function of the degree of unbalance of said bridge in one direction and emits no light when the bridge is unbalanced in the other direction.
Claim 17
Dependent Claim
137 words
for four impedance legs each connected between a different pair of one input and one output and one output node, b. at least one of a said impedance legs including an element having an impedance which varies significantly as a function of the temperature of the element; c. means for applying electrical power to said input nodes, and d. a series-connected diode and light source directly connected between the output nodes of said bridge, said diode being in a conducting state when said bridge is unbalanced in one direction and in a nonconducting state when said bridge is unbalanced in the other direction, whereby said light source means emits light as a function of the degree of unbalance of said bridge in one direction and emits no light when the bridge is unbalanced in the other direction.
Claim 18
Dependent Claim
29 words
A temperature control system including a temperature measuring device according to claim 1 for measuring the temperature of a fluid and further comprising: a. and RC circuit further comprising;
Claim 19
Dependent Claim
40 words
A temperature control system according to claim 3 wherein: a. said output means comprises an AC electrically operated heater element; b. said supply means comprises a source of a AC voltage and AC current; and c. said control means comprises:
Claim 20
Dependent Claim
35 words
A temperature control system according to claim 4 further comprising: a. an additional supply means for supplying a different phase of AC voltage and current to said output means; b. and additional RC circuit comprising;
Claim 21
Dependent Claim
10 words
A temperature measuring device comprising: a. a wheatstone bridge comprising;
Claim 22
Dependent Claim
10 words
A temperature measuring device comprising: a. a wheatstone bridge comprising;
Claim 23
Dependent Claim
20 words
A device as in claim 6 further including, a bias means coupled to said light source for prewarming said lamp.
References Cited (Backward Citations)
US3161759A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |