Abstract: A parking meter construction having an upper and lower housing with payment means for receiving coins or a payment card. A microprocessor and other electronic components are included on a PC board mounted in the upper housing. A modular jack is connected to terminals of the microprocessor for communication therewith, and the jack is supported in the meter for connection with any of a large variety of peripheral devices which can then utilize the microprocessor in their operation. A plurality of peripheral devices may be linked together and all kept in communication with the microprocessor.

Abstract: A coin-sensing system wherein at least two sensor coils are electrically connected in series and physically arranged so that a coin deposited into the apparatus may pass sequentially through each sensor coil and thereby change the impedance of the coil. A sensor oscillator circuit incorporates the sensor coils to output an oscillating sensor signal at a frequency dependent on the impedance of the sensor coils. Counters measure the frequency of the sensor signal to obtain a frequency signature for the deposited coin which can be compared with frequency signatures of valid coins. The oscillator circuit may produce a lower frequency oscillating sensor signal or a higher frequency oscillating sensor signal and electronic switches are included in the circuit for switching from one of the frequency levels to the other after the deposited coin encounters a first sensor coil and before the deposited coin encounters a second sensor coil.

Abstract: An electronic parking meter operating system comprising a microprocessor mounted within a meter housing, a semiconductor disc memory having at least 8K memory bytes, and a plurality of programs stored in the disc memory. A meter event such as the deposit of a coin will cause interrogation of an auxiliary program module map to determine if one of the plurality of programs should be used to substitute for or augment a program which is provided in the microprocessor to normally carry out meter functions. If substitution or augmentation is called for, an address table in the memory disc is used to locate the selected program, to load it into the microprocessor, and to execute the program.

Abstract: A combination key-like device and electrical receptacle for the key-like device wherein the receptacle defines electrical contact surface areas for mating with corresponding contact surface areas defined by the key-like device. At least one clip defines the electrical contact surface areas for the said receptacle and the clip is supported on the receptacle body. A keyway opening is defined by the body and the clip comprises a transverse portion and a pair of legs extending outwardly from the transverse portion with contact elements defined by each of the legs extending inwardly toward the keyway opening and with openings defined by the body communicating with said keyway opening for receiving the contact elements. A contact band is carried by the key-like device whereby insertion of the key-like device into the keyway opening brings the contact band into electrical contact with at least one of the contact elements.