Special fly-back switching power supply for wine cabinet of ice bar and electronic refrigeration type water dispenser

Abstract

The invention discloses a special fly-back switching power supply for a wine cabinet of an ice bar and an electronic refrigeration type water dispenser. The special fly-back switching power supply comprises a low-frequency rectification filter circuit, a switch adjustment tube transformer, a peak recovery circuit, a high-frequency rectification filter circuit, a double-temperature-point monitoring gating circuit, two switchable feedback voltage sampling circuits, a PWM (pulse-width modulation) integrated switch control circuit, and a short circuit and overload protecting circuit, which are connected in order; at the same time, the control signal of an ultra-low temperature threshold monitor in the double-temperature-point monitoring gating circuit is connected with the PWM (pulse-width modulation) integrated switch control circuit; the output control signal of the short circuit and overload protecting circuit is connected with the PWM (pulse-width modulation) integrated switch control circuit; the driving signal of the PWM (pulse-width modulation) integrated switch control circuit is connected with the switch adjustment tube transformer and the peak recovery circuit; in this way, a plurality of voltage power supply modes can be achieved; three work states, namely a normal refrigeration state, an insulation refrigeration state and an ultra-low temperature stop (preventing the freezing of cold water) state, can be effectively implemented, so that the load safety is guaranteed and the PWM (pulse-width modulation) integrated switch control circuit can be quickly protected when the PWM (pulse-width modulation) integrated switch control circuit is applied to a high-voltage of 12V and a low-voltage of 5V.

Description

Technical field: [0001] The invention relates to the technical field of switching power supplies, in particular to a flyback switching power supply dedicated to electronic cooling water dispensers and ice bar wine cabinets. Background technique: [0002] The loads of electronic cooling water dispensers and ice bar cabinets contain semiconductor cooling chips and cooling fans (DC12V). The basic requirements for the power supply of such products are: to provide high voltage in high temperature environment (for example, DC12V to achieve forced cooling), and to provide high voltage in low temperature environment. Low voltage (such as DC5V for weak refrigeration). At present, the traditional power supply of such products is improved on the basis of dual-tube push-pull switching power supply, and the flyback switching power supply has not been applied in this field. [0003] In the double-tube push-pull switching power supply (for example, composed of TL494), there are too many c...

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Problems solved by technology

[0003] In the double-tube push-pull switching power supply (for example, composed of TL494), there are too many components, the cost is expensive, the requirements for symmetrical components are strict, and the quality is difficult to guarantee; secondly, in order to meet the requirements of the water dispenser, the traditional heat preservation method of this type of power supply adopts Single-point temperature control plus ambient temperature compensation circuit, but this method will cause the power supply voltage to be too low (about 2V) when used in cold areas, which is very easy to damage the cooling fan, and cannot solve the problem of cold water freezing and blocking the water outlet; During low voltage operation (large current and small voltage drop), the typical short circuit or overload protection circuit is extremely insensitive and difficult to protect

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