Oscillator/demodulator circuit for an inductive proximity switch
Abstract
Abstract An oscillator/demodulator circuit for an inductive proximity switch includes a transistor amplifier stage having an input circuit and an output circuit, a resonant circuit connected in the input circuit of the transistor amplifier stage, a device for damping the resonant circuit, a device for providing positive feedback from the output circuit to the input circuit of the transistor amplifier stage, a limiter branch connected in the input circuit of the transistor amplifier stage, a dual current mirror active in the input circuit of the transistor amplifier stage having first and second interconnected current mirrors including transistors. It further has a circuit output connected to the current mirrors for receiving currents supplied by the current mirrors being subtracted from each other, the transistors in the second current reflector having a larger emitter area ratio than the transistors in the first current mirror, and a resistance network connected to the oscillator/demodulator circuit output being switchable for providing an adjustable hysteresis.
Inventors
- 👤 Gerhard Gehring
- 👤 Franz Hodlmayr
Bibliographic Details
Claims Analysis
Total Claims: 6References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |