Signal transmitter using an active thick film substrate
US4010447A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 7, 1976 |
| Grant date | Mar 1, 1977 |
| Priority date | — |
| Expiry date | Jan 7, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08C19/26
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A battery powered portable acoustic transmitter comprises a plurality of single-pole, momentary contact switches, a type 555 pulse producing integrated circuit chip, and an electroacoustic transducer and matching tuning coil. An RC timing circuit includes a plurality of resistors selectively connectable in the timing circuit by the switches to vary the pulse output frequency. A transistor output circuit amplifies the pulses for driving the transducer. A plurality of diodes supply power to the chip and the transistor output circuit whenever a switch is activated. The integrated circuit chip, resistors, diodes and transistor are part of an active thick film circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.