Electric remote control transmitter
US4021756A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1975 |
| Grant date | May 3, 1977 |
| Priority date | — |
| Expiry date | Jul 2, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB06B2201/70
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electronic remote control transmitter employs a two transistor cascade oscillator having positive and negative feedback loops. The oscillator voltage is supplied through a switch assembly containing a plurality of momentary contact switches to a pair of voltage dividers supplying signal voltages in predetermined ratios to a two branch circuit in the negative feedback loop. One branch contains an inductor and the second branch a capacitor. Closure of any switch completes the DC circuits for the transistors. Signal voltage is supplied to the branches to produce a minimum amplitude, zero phase shift condition which establishes oscillation at that predetermined frequency. The output of the oscillator is amplified by a third transistor and supplied to an ultrasonic transducer for generating acoustical control signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.