A permeable electrostatic shielding method and apparatus is disclosed that is suitable for use in shielding portable electronic devices such as calculators, smart cards and radios. Such electronic devices require protection from the electrostatic discharge occurring when a user accumulates an electrostatic charge and contacts a conducting surface of the electronic device. The resulting electrostatic discharge creates capacitively-coupled voltage transients in the digital circuits within the electronic device. The present invention prevents local charge accumulation on the surfaces of such electronic devices, which transmit and receive electromagnetic radio waves, without blocking the electromagnetic radiation essential to device function. One embodiment of this permeable electrostatic shield is formed by depositing a conductive layer of controlled thickness comprising a plurality of closely-spaced conductors that are electrically connected at one end to form a practical electrostatic shield permeable to RF electromagnetic radiation above 15 MHz.
An access control ticket having three fields of data, a first field (3) of fixed data, a second field (7) of variable data, and a third field (8) of variable data is read and information processed by a microprocessor. The microprocessor determines the validity of information on the ticket data fields and which of the variable fields has older data. Writing only occurs on (over) the variable field with invalid or older data. Upon subsequent use, the ticket contains current access data (just written) and last previous access data, as well as fixed field data. This added data (past use) can be used for statistical analysis or other purposes. More importantly, the added data field reduces read/write reliability problems. One improperly written variable data field does not invalidate ticket, only the last variable data entry. The microprocessor is programmed to overwrite invalid data in one of the variable data fields during the next use. Since the ticket still has the fixed data field and a prior use variable data field, no human intervention, repair of access control devices (for single failures), or new tickets are required. The location of variable use data can also be segregated from fixed data to further enhance reliability. This reduction in failures and tolerance of single non recurring errors allows hand held swipe type read/writer to be utilized for mass transit applications. Access is quick, avoiding manual ticket insertion, grabbing, transport and return.
A continuous strip of ticket stock from which individual tickets can be separated includes an elongated strip of a ticket stock material and, at each preselected ticket-separation location, a collinear transversely extending perforation, bursting slot, and slit at each end of the bursting slot. A ticket dispenser for dispensing individual tickets from such a strip of stock includes a drive mechanism that drives the strip of ticket stock in both a forward direction and a reverse direction through a bursting station. The bursting station includes a burst barb, and a guide that permits the strip of ticket stock to move past the burst barb when the strip of ticket stock is driven in the forward direction, and to engage the burst barb to the bursting slot when the strip of ticket stock is driven in the reverse direction. The burst barb propagates a separation from the bursting slot outwardly through the perforation to separate the individual ticket cleanly from the strip.
An access control ticket having three fields of data, a first field of fixed data, a second field of variable data, and a third field of variable data is read and information processed by a microprocessor. The microprocessor determines the validity of information on the ticket data fields and which of the variable fields has older data. Writing only occurs on (over) the variable field with invalid or older data. Upon subsequent use, the ticket contains current access data (just written) and last previous access data, as well as fixed field data. This added data (past use) can be used for statistical analysis or other purposes. More importantly, the added data field reduces read/write reliability problems. One improperly written variable data field does not invalidate ticket, only the last variable data entry. The microprocessor is programmed to overwrite invalid data in one of the variable data fields during the next use. Since the ticket still has the fixed data field and a prior use variable data field, no human intervention, repair of access control devices (for single failures), or new tickets are required. The location of variable use data can also be segregated from fixed data to further enhance reliability. This reduction in failures and tolerance of single non recurring errors allows hand held swipe type read/writer to be utilized for mass transit applications. Access is quick, avoiding manual ticket insertion, grabbing, transport and return.
A turnstile is made with a stationary turnstile support shaft extending from a solid support, and a bearing on the end of the shaft. The turnstile hub is supported on the end of the shaft with a bearing. The turnstile hub is locked against rotation in a fee-paid direction by a unidirectional pawl that engages a cutout on a ratchet plate attached to the hub. The unidirectional pawl is released by energizing a solenoid latching mechanism, rather than acting directly on the unidirectional pawl. Backcocking of the turnstile is prevented by a bidirectional pawl that engages notches on the ratchet plate. The bidirectional pawl is released by energizing a second solenoid latching mechanism, rather than acting directly on the bidirectional pawl.