Abstract: A vending machine monitoring method used in a vending machine monitoring system, which includes an automatic vending machine and a monitoring system that is attached to the automatic vending machine and uses a microprocessor to read in data signals transmitted between the main controller and peripheral apparatus (card-slide unit, bill acceptor, license recognition unit and coin slot unit) of the automatic vending machine through a connection interface, to process fetched data signals into waveform signals, to indicate any error message through an indicator light module, and to report processed waveform signals to an external remote system through a transmission module for display and further analysis and check of income.

Abstract: The invention presents a switching control circuit for a primary-side-controlled power converter. A pattern generator produces a digital pattern to control a programmable capacitor that is connected to an oscillator, which produces frequency hopping to reduce the EMI. A voltage-waveform detector produces a voltage-feedback signal and a discharge-time signal by multi-sampling a voltage signal of a transformer. A current-waveform detector and an integrator generate a feedback signal. The integration of a current-waveform signal with a timing signal generates the average-current signal. Time constant of the integrator is correlated to the switching frequency. The oscillator generates the timing signal and a pulse signal in response to the output of a current-loop error amplifier. A PWM circuit generates the switching signal in response to the pulse signal and the output of a voltage-loop error amplifier for switching the switching device and regulating the output of the power converter.

Abstract: A power-mode control circuitry is presented for power converters to precisely control a maximum of the output power. The power-mode control circuitry includes a filter to convert a switching current into an average-current signal. A voltage divider attenuates an input voltage of the power converter to an average-voltage signal. A multiplier produces a power signal by multiplying the average-current signal with the average-voltage signal. An error amplifier generates a programming signal by comparing the power signal with a power-level threshold. The programming signal further controls the switching signal for achieving power-mode control.