Inventor
CARMEN RALPH H
US17 patents
⚠️ This page may combine multiple inventors who share the name “CARMEN RALPH H”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
DUNCAN IND PARKING CONTROL SYS
9 patentsUS5841369ANov 24, 1998
Parking meter with peripheral functions
DUNCAN IND PARKING CONTROL SYS160 citations97
US5382780AJan 17, 1995
Portable time metering device
DUNCAN IND PARKING CONTROL SYS89 citations96
US5273151ADec 28, 1993
Resonant coil coin detection apparatus
DUNCAN IND PARKING CONTROL SYS125 citations95
US5244070ASep 14, 1993
Dual coil coin sensing apparatus
DUNCAN IND PARKING CONTROL SYS134 citations95
US5184707AFeb 9, 1993
Coin operated timing mechanism
DUNCAN IND PARKING CONTROL SYS64 citations95
US5109972AMay 5, 1992
Coin operated timing mechanism
DUNCAN IND PARKING CONTROL SYS91 citations95
US5805083ASep 8, 1998
Electronic parking meter operating system
DUNCAN IND PARKING CONTROL SYS82 citations94
US5155614AOct 13, 1992
Low-power demodulating receiver with amplifier stages sharing the same bias current
DUNCAN IND PARKING CONTROL SYS102 citations94
US5806651ASep 15, 1998
Coin discrimination system
DUNCAN IND PARKING CONTROL SYS126 citations93