US4063121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Input converter
Assignee: Mehta Tech Inc
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Filing: 1976-07-22
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Granted: 1977-12-13
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Expires: 1996-07-22
Abstract
Abstract An input converter circuit for producing a logic level indication of the on or off condition of an input. The input may be AC or DC at any reasonable level. A bilateral photocoupler output is applied to an operational amplifier integrator, which establishes the integration time of the signal. The amplifier output is coupled to a Schmitt trigger having threshold levels at about one third and two thirds of the power supply voltage. The output of the Schmitt trigger provides a logic one output if there is an input signal present and a logic zero output otherwise.
Inventors
- 👤 Peter G. Bartlett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:06
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/165; G01R19/16533; G01R19/16557; H; H03; H03K; H03K3/00; H03K3/02; H03K3/027; H03K3/037; H03K3/0377
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
63 words
An input signal converter comprising: 1. an input coupled from an input signal source; 2. light emitting means coupled to said input for producing light in response to input signals; 3. a light sensitive semiconductor device positioned adjacent said light emitting means; 4. an amplifier having a low voltage, current sensitive, low impendance input connected in shunt across said light sensitive device; and
Claim 2
Dependent Claim
63 words
An input signal converter comprising: 1. an input coupled from an input signal source; 2. light emitting means coupled to said input for producing light in response to input signals; 3. a light sensitive semiconductor device positioned adjacent said light emitting means; 4. an amplifier having a low voltage, current sensitive, low impendance input connected in shunt across said light sensitive device; and
Claim 3
Dependent Claim
19 words
a constant current source supplying current to the shunted pair of said light sensitive device and said amplifier input.
Claim 4
Dependent Claim
19 words
a constant current source supplying current to the shunted pair of said light sensitive device and said amplifier input.
Claim 5
Dependent Claim
23 words
The input converter of claim 1 in which said light emitting means includes two light emitting diodes in parallel connection of opposite polarity.
Claim 6
Dependent Claim
19 words
The input converter of claim 1 which further comprises a Schmitt trigger coupled to the output of said amplifier.
Claim 7
Dependent Claim
20 words
The input converter of claim 1 in which the voltage across said shunted pair does not exceed about 0.6 volt.
Claim 8
Dependent Claim
41 words
The input converter of claim 1 in which said amplifier is a two-input current operational amplifier having a second input coupled from a second current source and having a capacitor coupled from the output of the amplifier to said second input.
Claim 9
Dependent Claim
30 words
The input converter of claim 5 in which the second input of the two input amplifier is its minus input and in which the shunted pair includes the plus input.
Claim 10
Dependent Claim
58 words
The input converter of claim 1 in which said light sensitive device is a phototransistor and said constant current source provides current of a value such that the voltage at the collector of said phototransistor is no more than about the base-to-emitter turn-on voltage of said phototransistor and no less than the collector-to-emitter saturation voltage of the phototransistor.
Claim 11
Dependent Claim
19 words
The input converter of claim 7 in which there are no external connections to the base of the phototransistor.
Claim 12
Dependent Claim
20 words
The input converter of claim 8 in which the voltage across said shunted pair does not exceed about 0.6 volt.
Claim 13
Dependent Claim
41 words
The input converter of claim 9 in which said amplifier is a two-input current operational amplifier having a second input coupled from a second current source and having a capacitor coupled from the output of the amplifier to said second input.
Claim 14
Dependent Claim
19 words
The input converter of claim 10 which further comprises a Schmitt trigger coupled to the output of said amplifier.
Claim 15
Dependent Claim
23 words
The input converter of claim 3 in which said light emitting means includes two light emitting diodes in parallel connection of opposite polarity.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-12 | 1981-06-13 | 1981-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-12 | 1985-06-13 | 1985-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-12 | 1989-06-13 | 1989-12-13 | $7700.00 | Window Closed / Lapsed |