US3609407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic trigger level control circuit
Assignee: Tektronix Inc
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Filing: 1969-06-09
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Granted: 1971-09-28
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Expires: 1989-06-09
Abstract
Abstract A circuit is disclosed for automatically varying the trigger level of a trigger circuit in order to maintain this level substantially proportional to the amplitude of a series of similar waveforms of an input signal. A peak detector provides a voltage substantially proportional to the peak voltage of the input waveforms. A manually adjustable fraction of the detected voltage is delivered to a control circuit as a control voltage to cause selection of increments of the input waveforms crossing a signal voltage level of these waveforms corresponding to the control voltage. The control circuit supplies control signals corresponding to such increments to a trigger circuit at a signal level which causes the trigger circuit to produce trigger pulses when the varying voltages of the input waveforms cross a signal level within the selected increments. This signal level remains substantially proportional to the peak voltage of the input signal waveforms even though this peak voltage changes.
Inventors
- 👤 Valdis E Garuts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:14
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/01; H03K5/08; H03K5/082; H03K3/00; H03K3/02; H03K3/26; H03K3/28; H03K3/281; H03K3/286; H03K3/2893
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
171 words
An automatic trigger level control circuit which comprises: means including an input amplifier means and detector means connected to the output of said input amplifier means for obtaining from an input signal having a series of similar waveforms a detected voltage which is substantially proportional to the peak voltage of said waveforms; output circuit means including means for obtaining from said detected voltage a control voltage proportional to a selected fraction of said detected voltage; control means including a nonlinear signal transfer means providing a feedback circuit between said output circuit means and said input amplifier means and responsive to said control voltage for selecting increments of said waveforms extending across an input signal level corresponding to said selected fraction and delivering said increments to said output circuit means; said output circuit means also including output amplifier means for amplifying said increments and trigger means responsive to the amplified increments for producing trigger signals when said amplified increments cross said signal level corresponding to said selected fraction of said detected voltage.
Claim 2
Dependent Claim
171 words
An automatic trigger level control circuit which comprises: means including an input amplifier means and detector means connected to the output of said input amplifier means for obtaining from an input signal having a series of similar waveforms a detected voltage which is substantially proportional to the peak voltage of said waveforms; output circuit means including means for obtaining from said detected voltage a control voltage proportional to a selected fraction of said detected voltage; control means including a nonlinear signal transfer means providing a feedback circuit between said output circuit means and said input amplifier means and responsive to said control voltage for selecting increments of said waveforms extending across an input signal level corresponding to said selected fraction and delivering said increments to said output circuit means; said output circuit means also including output amplifier means for amplifying said increments and trigger means responsive to the amplified increments for producing trigger signals when said amplified increments cross said signal level corresponding to said selected fraction of said detected voltage.
Claim 3
Dependent Claim
26 words
The circuit in accordance with claim 1 in which; said output circuit means includes manually adjustable means for varying said selected fraction of said detected voltage.
Claim 4
Dependent Claim
48 words
The circuit of claim 1 in which: said input amplifier means includes means for increasing the amplification of said input amplifier means during the time each of said increments is being delivered to said output circuit means so as to compensate for voltage drops in said detector means.
Claim 5
Dependent Claim
122 words
The circuit in accordance with claim 3 in which; the input amplifier means includes a differential amplifier having a plus input connected to receive said waveforms of said input signal, and a minus low impedance input providing a voltage which follows a voltage applied to said plus input and an output connected to said detector means; the output amplifier means also includes a differential amplifier having a plus input connected to the output of said detector means, a minus low impedance input providing a voltage which follows the voltage applied to the plus input of said output amplifier and an output connected to said trigger means; and said nonlinear signal transfer means is connected between the minus inputs of said differential amplifiers.
Claim 6
Dependent Claim
50 words
The circuit in accordance with claim 4 in which; said nOnlinear signal transfer means includes means responsive to changes in the voltage between the connections of said nonlinear signal transfer means to said differential amplifiers for producing substantially proportional changes in the current through said connections during said increments only.
Claim 7
Dependent Claim
32 words
The circuit in accordance with claim 5 in which; said output amplifier means has means for causing its output current to vary substantially proportionally to the changes in current through said connections.
Claim 8
Dependent Claim
61 words
The circuit in accordance with claim 9 in which: said means for increasing the amplification of said input amplifier means is a feedback circuit from the output to the minus input of the differential amplifier of said input amplifier which feedback circuit also supplies current to said nonlinear signal transfer means during delivery of said increments to said output circuit means.
Claim 9
Dependent Claim
100 words
The circuit in accordance with claim 4 in which: the nonlinear signal transfer means includes a pair of unidirectional conductive means connected in series between said minus inputs of said differential amplifiers for current flow in opposite directions and a constant current source connected to a point between said unidirectional conductive means so that current flow through said unidirectional conductive means varies in opposite directions to substantially the same extent as the voltage at the minus input of one of said differential amplifiers varies with respect to the voltage at the minus input of the other of said differential amplifiers.
Claim 10
Dependent Claim
64 words
The circuit in accordance with claim 8 in which; said means for obtaining a selected fraction of said detected voltage includes manually adjustable means for varying the fraction of said detected voltage applied to the plus input of said differential amplifier of said output amplifier means to thereby control the voltage at the minus input of said differential amplifier of said output amplifier means.
Claim 11
Dependent Claim
105 words
The circuit in accordance with claim 11 in which; said differential amplifier of said output amplifier means includes an output transistor having its emitter connected to said minus input of said differential amplifier of said output amplifier means and its collector connected to the input of said trigger means; and circuit means connected to said transistor for converting a change of emitter current of said transistor due to a change of current through said unidirectional conductive means of said nonlinear signal transfer means to a voltage change at the input of said trigger means causing the production of said trigger signals during said increments only.
Claim 12
Dependent Claim
53 words
The circuit in accordance with claim 10 in which said trigger means produces said trigger signals in response to a range of voltage which corresponds to ranges of voltages of the input signal of the trigger level control circuit and which are less than and contained in the voltage ranges of said increments.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |