Power supply priority selection circuit applied to portable safe box

Abstract

The embodiment of the utility model discloses a power supply priority selection circuit applied to a portable safe box, which comprises a triode Q1, a triode Q2, a triode Q3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a diode D1 and a diode D2, a G electrode of the triode Q2 is connected with a collector electrode of the triode Q1 and is connected with a GND end through a resistor R5, an emitting electrode of the triode Q1 and an S electrode of the triode Q2 are connected with the GND end, a D electrode of the triode Q3 is connected with a post-stage circuit through a diode D2, and the S electrode and the G electrode of the triode Q3 are respectively connected with a battery end and the D electrode of the triode Q2. Under the condition that the portable safe box is simultaneously provided with four dry batteries and an external 5V adapter for power supply, the external adapter is preferentially used, so that the electric energy of the dry batteries is not consumed as far as possible, the endurance time of the portable safe box is longer after the external adapter is pulled out, and the user experience is enhanced.

Description

TECHNICAL FIELD

[0001] The utility model relates to portable safe field especially, it relates to a power supply priority selection circuit applied to portable safe. BACKGROUND

[0002] The existing portable safe with electronic unlocking (such as password, fingerprint, etc.) generally adopts four dry batteries and external 5V adapter dual power supply. Usually, one diode is directly used in each of the two power supplies to supply power to the subsequent circuit, and whichever voltage is high, whichever power supply is preferentially supplied. In the traditional scheme, when four dry batteries and external 5V adapter dual power supply, the battery voltage is greater than 5V, which will preferentially consume the battery power, so that the subsequent navigation time after the 5V adapter is removed becomes very short, which is not conducive to user experience. SUMMARY

[0003] The technical problem to be solved by the embodiments of the utility model lies in providing a power supply priority selection circuit applied to a portable safe to improve the subsequent navigation time of the portable safe after the external 5V adapter is removed.

[0004] In order to solve the above technical problem, the utility model embodiment proposes a power supply priority selection circuit applied to a portable safe, which comprises a triode Q1, a triode Q2, a triode Q3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a diode D1 and a diode D2. The positive and negative electrodes of the diode D1 are respectively connected to the positive electrode of the external power supply and the subsequent circuit. The collector of the triode Q1 and the D pole of the triode Q2 are respectively connected to the positive electrode of the battery end through the resistor R4 and the resistor R6. The G pole of the triode Q2 is connected to the collector of the triode Q1 and connected to the GND end through the resistor R5. The emitter of the triode Q1 and the S pole of the triode Q2 are connected to the GND end. The D pole of the triode Q3 is connected to the subsequent circuit through the diode D2. The S pole and the G pole of the triode Q3 are respectively connected to the battery end and the D pole of the triode Q2. One end of the resistor R3 is connected to the base of the triode Q1, and the other end is respectively connected to the positive electrode of the external power supply and the GND end through the resistor R1 and the resistor R2.

[0005] Further, it further comprises a capacitor EC1, and the two ends of the capacitor EC1 are respectively connected to the subsequent circuit and the GND end.

[0006] Further, the triode Q1 is an NPN type triode.

[0007] Further, the triode Q2 and the triode Q2 are respectively N channel MOS tube and P channel MOS tube.

[0008] The utility model discloses a beneficial effect is: the utility model discloses portable safe can make four dry batteries and external 5V adapter power supply under the condition of simultaneously taking, preferentially use external adapter, make dry battery electric energy as far as possible not loss, when portable safe removes external adapter subsequent navigation time is longer, enhances user experience. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 It is the circuit diagram of the power supply priority selection circuit of the utility model embodiment applied on portable safe. DETAILED DESCRIPTION

[0010] It needs to be explained that the embodiment and the feature in the embodiment in the application can be combined mutually in the case of not conflicting, and the utility model will be explained further in detail in the following with the combination of the drawings and specific embodiment.

[0011] The directionality indication in the utility model embodiment, such as up, down, left, right, front, back, is only used for explaining the relative position relationship, movement condition and the like between components in a certain specific posture (such as shown in the drawings), if the specific posture changes, then the directionality indication also changes accordingly.

[0012] In addition, the description of "first", "second" and the like in the utility model is only used for the description purpose, and can not be understood as indicating or suggesting the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the feature with "first", "second" can explicitly or implicitly include at least one feature.

[0013] Please refer to Figure 1 The power supply priority selection circuit of the utility model embodiment applied on portable safe includes triode Q1, triode Q2, triode Q3, resistance R1, resistance R2, resistance R3, resistance R4, resistance R5, resistance R6, diode D1, diode D2.

[0014] The positive and negative poles of diode D1 are respectively connected with the positive pole of external power supply (i.e. the adapter end of the portable safe) and the rear circuit (i.e. VOUT, which is used for supplying power for the electronic unlocking part of the portable safe), the collector of triode Q1 and the D pole of triode Q2 are respectively connected with the positive pole of the battery end (i.e. the dry battery end of the portable safe) through resistor R4 and resistor R6, the G pole of triode Q2 is connected with the collector of triode Q1 and is connected with the GND end through resistor R5, the emitter of triode Q1 and the S pole of triode Q2 are connected with the GND end, the D pole of triode Q3 is connected with the rear circuit through diode D2, and the S pole and G pole of triode Q3 are respectively connected with the battery end and the D pole of triode Q2; one end of resistor R3 is connected with the base of triode Q1, and the other end is respectively connected with the positive pole of external power supply and the GND end through resistor R1 and resistor R2.

[0015] As an implementation form, the power supply priority selection circuit applied to the portable safe further comprises a capacitor EC1, and the capacitor EC1 is connected with the rear circuit and the GND end respectively.

[0016] As an implementation form, the triode Q1 is an NPN triode.

[0017] As an implementation form, the triode Q2 and the triode Q3 are an N-channel MOS tube and a P-channel MOS tube respectively.

[0018] The working principle of the utility model is as follows:

[0019] 1. When only the external adapter 5V_IN supplies power, the rear circuit is supplied with power through D1 diode to VOUT.

[0020] 2. When only BAT-4C (four dry batteries) supplies power, Q1 (NPN triode) is cut off, BAT-4C is divided through R4 and R5 and then reaches the gate of Q2 (N-channel MOS tube), Q2 is turned on, the gate of Q3 (P-channel MOS tube) is pulled down to GND, i.e. the gate has a negative voltage to the source, Q3 is turned on. BAT-4C supplies power to the rear circuit through Q3 and D2.

[0021] 3. When BAT-4C and the external adapter 5V_IN exist simultaneously, 5V_IN is divided through R1 and R2 and then drives Q1 through R3, Q1 is saturated and turned on, the gate voltage of Q2 is pulled down, and Q2 and Q3 are not turned on according to the above 2, so only 5V_IN supplies power to the rear circuit through D1, and the power supply priority selection is realized.

[0022] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalent ranges.

Claims

1. A power supply priority selection circuit for use in a portable safe, characterized in that, It comprises triode Q1, triode Q2, triode Q3, resistance R1, resistance R2, resistance R3, resistance R4, resistance R5, resistance R6, diode D1, diode D2, the positive and negative electrodes of diode D1 are connected with the positive electrode of external power supply and the rear stage circuit respectively, the collector of triode Q1 and the D pole of triode Q2 are connected with the positive electrode of battery end through resistance R4 and resistance R6 respectively, the G pole of triode Q2 is connected with the collector of triode Q1 and is connected with GND end through resistance R5, the emitter of triode Q1 and the S pole of triode Q2 are connected with GND end, the D pole of triode Q3 is connected with the rear stage circuit through diode D2, the S pole and G pole of triode Q3 are connected with the battery end and the D pole of triode Q2 respectively; one end of resistance R3 is connected with the base of triode Q1, the other end is connected with the positive electrode of external power supply and GND end through resistance R1 and resistance R2 respectively.

2. The power prioritization circuit for use on a portable safe of claim 1, wherein, It also comprises capacitor EC1, the two ends of capacitor EC1 are connected with the rear stage circuit and GND end respectively.

3. The power prioritization circuit for use on a portable safe of claim 1, wherein, Triode Q1 is NPN type triode.

4. The power prioritization circuit for use on a portable safe of claim 1, wherein, Triode Q2 and triode Q2 are N channel MOS tube and P channel MOS tube respectively.

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