Abstract: Disclosed is a system comprising a plurality of operational amplifiers, each operational amplifier having individually adjustable operational parameters, and a trimming circuit. The trimming circuit includes successive approximation register (SAR) logic that determines associated memory values. The trimming circuit changes the adjustable operational parameters of each operation amplifier based on the associated memory values.

Abstract: Disclosed is a system that comprises an operational amplifier with adjustable operational parameters and a trimming module. The trimming module can adjust the operational parameters of the op-amp based on a memory value to compensate for an offset voltage of the op-amp. The trimming module can comprise successive approximation register (SAR) logic that controls the memory value. The SAR logic can be configured to detect a given memory value that causes an output voltage of the op-amp to be within a predetermined voltage interval when applying a predetermined common mode voltage to inverting and non-inverting inputs of the op-amp.

Abstract: Disclosed is a system comprising a plurality of operational amplifiers, each operational amplifier having individually adjustable operational parameters, and a trimming circuit. The trimming circuit includes successive approximation register (SAR) logic that determines associated memory values. The trimming circuit changes the adjustable operational parameters of each operation amplifier based on the associated memory values.

Abstract: Disclosed is a system that comprises an operational amplifier with adjustable operational parameters and a trimming module. The trimming module can adjust the operational parameters of the op-amp based on a memory value to compensate for an offset voltage of the op-amp. The trimming module can comprise successive approximation register (SAR) logic that controls the memory value. The SAR logic can be configured to detect a given memory value that causes an output voltage of the op-amp to be within a predetermined voltage interval when applying a predetermined common mode voltage to inverting and non-inverting inputs of the op-amp.

Abstract: A vending machine cabinet is retained in a closed position by a hook that is engaged by a vertically moveable latch bar that can be latched closed without requiring a solenoid. The latch bar is moved by means of a cam attached to one of the hooks. Prior to engaging the hook, an angled surface of the cam engages a surface defined by the opening in the latch bar. As the door is closed, the cam rotates through an angle thereby lifting the latch bar until the upwardly extending finger of the hook can move through the opening of the latch bar. When the door is fully closed, the surface of the cam is moved from beneath the edge of the opening in the latch bar thereby allowing the latch bar to drop behind the hook, latching the door closed.

Abstract: A vending machine cabinet that is retained in a closed position by a hook that is engaged by a vertically moveable latch bar can be latched closed without actuating a solenoid by means of a cam attached to one of the hooks. To engage the latch bar, the hook extends through an opening in the latch bar. Prior to the hook passing through the opening, an angled surface of the cam engages an upper surface defined by the opening in the latch bar. As the door is closed, the cam rotates through an angle less than ninety degrees, thereby lifting the latch bar until the upwardly extending finger of the hook can move through the opening of the latch plate. When the door is fully closed, the surface of the cam is moved from beneath the upper edge of the opening in the latch plate thereby allowing the latch plate to drop behind the hook, latching the door closed.

Abstract: An illuminated lens is provided to illuminate the interior of a vending machine so that prospective patrons of the machine can see the products being offered for sale. Around the outer ends of the transparent lens is a frame made of aluminum, and deposited along the inner surface of the aluminum frame are deposits for forming a plurality of spaced LEDs. The light from the LEDs is directed into the outer end of the lens to thereby illuminate objects behind the lens.

Abstract: A door of a vending machine has an electrically operated lock that is operated by a hand held unit from outside the machine. In one embodiment of the lock a spike with grooves along the length thereof is engaged by an engagement unit having moveable blades. In a second embodiment a threaded screw is driven by a reversible motor to thread and unthread the screw into a threaded opening. The machine has detectors that detect the amount of product being dispensed by the machine and the amount of cash in the cash box and microprocessors and transceivers in both the machine and in the hand held unit convey this information to the hand held unit. The hand held unit may also program a slave hand held unit to have limited control over the functions of the machine.