Abstract: Discrimination between genuine coins and unacceptable coins (i.e., slugs) deposited in a coin-actuated vending machine, is achieved by guiding a deposited coin for movement along a guide path, and positioning a disk-shaped coil which forms part of an oscillator circuit at a certain position relative to the first guide path such that coins of certain diameters will interact with flux produced by the coil when the latter is excited by the oscillator circuit and the coins are guided in proximity with the coil. Amplitude and frequency values each corresponding to operation of the oscillator circuit (1) in the absence of a proximate coin, and (2) when a deposited coin is at positions along the first guide path which are in proximity with the coil, are measured. Degrees of shift in the amplitude and the frequency values between measurements made at (1) and (2) are then determined. The determined degrees of shift are compared against known shift limits for acceptable (i.e.

Abstract: A theft deterrent device restricts the number of newspapers or other periodicals that can be retrieved from a newspaper vending machine at one time. The device includes a cover gate forming a generally T-shaped opening with a vertical passageway and a horizontal slot opening. The cover gate mounts over an access opening of the vending machine behind a hinged door that closes against the vending machine. The cover gate restricts the number of periodicals that can be withdrawn at one time from a storage cabinet portion of the machine after the hinged door is opened and lowered by a customer. The deterrent device is easily installed on existing newspaper vending machines by way of an engagement member that securely engages a fixed part of the vending machine in the region of the access opening. A lock mechanism on the cover gate serves to lock the cover gate to the dispensing machine and firmly hold the gate in place over the access opening.