Abstract: A radio frequency noise reduction device and methods of operation are presented. The radio frequency noise reduction device identifies radio frequency noise on an isolated power plane of an electronic apparatus and generates an electrical signal that is injected into the isolated power plane and cancels the identified radio frequency noise. The generated electrical signal matches the frequency spectrum and amplitude of the identified radio frequency noise but the phase of the generated electrical signal is shifted by 180 degrees from the identified radio frequency noise.

Abstract: A radio frequency noise reduction device and methods of operation are presented. The radio frequency noise reduction device identifies radio frequency noise on an isolated power plane of an electronic apparatus and generates an electrical signal that is injected into the isolated power plane and cancels the identified radio frequency noise. The generated electrical signal matches the frequency spectrum and amplitude of the identified radio frequency noise but the phase of the generated electrical signal is shifted by 180 degrees from the identified radio frequency noise.

Abstract: An escrow vending machine has a secure, locking cabinet; a dispenser for cards or other merchandise; a bill acceptor, coin acceptor or similar cash acceptor; and a controller board within the cabinet and connected to the dispenser and to the cash acceptor. The dispenser contains a supply of prepaid telephone cards or other merchandise, and dispenses them one at a time in response to a control signal. The cash acceptor accepts and registers units of cash, e.g., dollars, and generates a pulse or other signal for each unit accepted. The controller board has an input that receives the cash signal from the cash acceptor and an output supplying the control signal to the dispenser. An escrow counter or register accumulates an escrow count of the pulses or cash signals. This enables the controller board to supply the control signal when the count in the escrow register equals or exceeds a preset number that represents a price or value.