Communications: electrical – Condition responsive indicating system – With particular system function
Patent
1996-11-22
1998-11-10
Hofsass, Jeffery A.
Communications: electrical
Condition responsive indicating system
With particular system function
34082569, 34082572, 307 103, G08B 2600
Patent
active
058350101
ABSTRACT:
The power feeding efficiency and the communicable range of an automatic answering system are improved in an automatic answering system using a transponder which performs code communication using amplitude modulation of a carrier with an electromagnetic coupling transponder mounted in a key or the like. In a transceiver for performing the code communication with the transponder via an antenna coil, a circuit for driving the antenna coil in a transceiver based on clock is implemented by a bridge-type complementary circuit of transistors. Thereby, driving current is increased. Meanwhile, a circuit for controlling the driving mode based on a write signal is implemented by a parallel circuit of a transistor to which a power-supply voltage is applied and a resistor. Thereby, a current corresponding to a resistance of the resistor flows through the antenna coil even during the minimum driving when the transistor is turned off, thus improving the power feeding efficiency and the communicable range of the system.
REFERENCES:
patent: 4918955 (1990-04-01), Kimura et al.
patent: 5280633 (1994-01-01), Camiade et al.
patent: 5287112 (1994-02-01), Schuermann
patent: 5287113 (1994-02-01), Meier
patent: 5619529 (1997-04-01), Fujioka
"RF Transponder Embedded in Auto Ignition Keys Stymies Car Thieves", Electronic Design 41 Dec. 1993 No. 25.
"Preliminary Device Specification Basestation IC", RF-Basestation IC for Communication with Philips Transponders, Philips Semiconductors, Jul. 1994.
PCF7930XP/030612 Date Sheet, Philips Semiconductors, Jul. 1994.
Asakura Fumio
Goto Masahiro
Kitahara Takahide
Okumura Ryozo
Yoshida Kiyokazu
Denso Corporation
Hofsass Jeffery A.
Nippon Soken Inc.
Pope Daryl C.
LandOfFree
Automatic answering system using transponder does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automatic answering system using transponder, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic answering system using transponder will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1520593