CN109478078A

CN109478078A - RTC clock power supply circuit

Info

Publication number: CN109478078A
Application number: CN201780030208.XA
Authority: CN
Inventors: 马晗清
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2017-03-07
Filing date: 2017-05-10
Publication date: 2019-03-15
Also published as: CN206546532U; WO2018161430A1

Abstract

A kind of RTC clock power supply circuit, including power supply (Vc), RTC clock power supply circuit further include bleeder circuit (1) and emitter follower circuit (2)；The input terminal of bleeder circuit (1) connects power supply (Vc), by the input terminal of output after power supply (Vc) partial pressure to emitter follower circuit (2), the output end of emitter follower circuit (2) is connected to the power pins (31) of RTC clock (3), by the way that bleeder circuit (1) and emitter follower circuit (2) are arranged between power supply (Vc) and power pins (31), RTC clock (3) are provided with stable operating voltage, and the voltage of power supply (Vc) and RTC clock (3) power pins (31) between the two is enabled to match.

Description

RTC clock power supply circuit

Technical Field

The invention relates to the technical field of power supplies, in particular to a Real-Time Clock (RTC) Clock power supply circuit.

Background

The RTC clock power of the chip is generally directly provided by the power supply battery, and when the voltage of the power supply battery is too large and the voltage of the power supply battery is not matched with the voltage of the power supply pin of the RTC clock, an intermediate circuit is needed to realize voltage matching, so that the normal work of the RTC clock is maintained.

At present, in order to solve the voltage matching problem existing in the RTC clock power supply, a DC-DC or LDO chip (low dropout regulator) is adopted to reduce the voltage of a power supply battery to a certain fixed value and then supply the voltage to a power pin of the RTC clock, so that the voltage of the power supply is matched with the power supply voltage of the power pin of the RTC clock, and the RTC clock works normally. However, the DC-DC or LDO chip has the problems of high circuit cost and high power consumption.

Disclosure of Invention

In view of the above, the present invention provides a RTC clock supply circuit.

Specifically, the invention is realized by the following technical scheme:

an RTC clock supply circuit comprises a power supply, a voltage division circuit and an emitter follower circuit;

the input end of the voltage division circuit is connected with the power supply, the power supply is divided and then output to the input end of the emitter follower circuit, and the output end of the emitter follower circuit is connected to a power pin of an RTC clock.

Optionally, the voltage divider circuit includes a first resistor and a second resistor.

Alternatively, the first resistor has one end connected to ground and the other end connected to an input terminal of the emitter follower circuit.

Alternatively, the second resistor has one end connected to the power supply and the other end connected to an input terminal of the emitter follower circuit.

Optionally, the emitter follower circuit comprises a transistor, the input of the emitter follower circuit is a base of the transistor, and the output of the emitter follower circuit is an emitter of the transistor.

Optionally, the emitter follower circuit further includes a third resistor, one end of the third resistor is connected to the emitter of the transistor, and the other end of the third resistor is grounded;

an output terminal of the emitter follower circuit is a non-ground terminal of the third resistor.

Optionally, the other end of the third resistor is connected to the first resistor grounded after passing through the base of the triode.

Optionally, the power supply is connected to a collector of the triode.

Optionally, the output of the emitter follower circuit is connected to ground via a capacitor.

Optionally, the power supply is a battery.

Optionally, the battery is a secondary battery.

According to the technical scheme provided by the embodiment of the invention, the voltage division circuit and the emitter follower circuit are arranged between the power supply and the power supply pin, firstly, the voltage reduction is realized by the voltage division of the voltage division circuit, and then the divided voltage of the voltage division circuit is stabilized based on the characteristics of high input impedance and low output impedance of the emitter follower circuit, so that the stable power supply voltage is provided for the RTC clock; the voltage divider circuit and the emitter follower circuit are arranged between the power supply and a power supply pin of the RTC clock, and the voltage between the power supply and the power supply pin of the RTC clock can be matched through the voltage divider circuit and the emitter follower circuit; in addition, the voltage divider circuit and the emitter follower circuit have simple circuit elements, low cost and low power consumption.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a schematic structural diagram of an RTC clock power supply circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an RTC clock supply circuit according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an RTC clock supply circuit according to another embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a remote controller provided in the present invention;

fig. 5 is a schematic structural diagram of another remote controller provided by the present invention.

Reference numerals:

vc: a power supply; GND: a ground terminal; v: the supply voltage of the RTC clock;

1: a voltage dividing circuit; r1: a first resistor; r2: a second resistor;

2: an emitter follower circuit; q: a triode; b: a base electrode; c: a collector electrode; e: an emitter; r3: a third resistor; c1: a capacitor;

3: an RTC clock; 31: a power supply pin.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims. In addition, the features in the embodiments and the examples described below may be combined with each other without conflict.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present invention. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

Referring to fig. 1, the RTC clock supply circuit according to the embodiment of the present invention may include a power supply Vc, a voltage divider circuit 1, and an emitter follower circuit 2.

The input end of the voltage dividing circuit 1 is connected with the power supply Vc, the output end of the voltage dividing circuit 1 is connected with the input end of the emitter follower circuit 2, and the output end of the emitter follower circuit 2 is connected to a power supply pin 31 (shown in fig. 1) in the RTC clock 3.

In this embodiment, the voltage dividing circuit 1 firstly reduces the voltage of the power supply Vc through a voltage dividing manner, and then stabilizes the divided voltage based on the characteristics of the high input impedance and the low output impedance of the emitter follower circuit 2, and finally the emitter follower circuit 2 outputs the stabilized divided voltage to the power supply pin 31, so as to provide a stable operating voltage for the RTC clock 3 and maintain the normal operation of the RTC clock 3.

Further, in the present embodiment, the voltage divider circuit 1 and the emitter follower circuit 2 are provided between the power supply Vc and the power supply pin 31, the voltages between the power supply Vc and the power supply pin 31 of the RTC clock 3 can be matched by the voltage divider circuit 1 and the emitter follower circuit 2, and the voltage divider circuit 1 and the emitter follower circuit 2 require simple circuit elements, low cost, and small power consumption.

In some examples, the power supply Vc may be selected as a battery, and the RTC clock 3 can be prevented from stopping after the power supply of the system (i.e., the system where the RTC clock 3 is located) is powered off by selecting the power supply Vc as an independent power supply battery. Further, the battery may be a storage battery for recycling to save resources.

Of course, in other examples, in order to avoid the problem of repeated replacement caused by using a battery as the power supply Vc, the power supply Vc may also be selected as a system power supply of the system where the RTC clock 3 is located.

It should be noted that, in this embodiment, the system where the RTC clock 3 is located may be a flight control system, and the flight control system may be applied to an aircraft to control the flight operation of the aircraft. The aircraft can be an unmanned aircraft, a remote control plane and other aircraft.

Referring to fig. 2, in a possible embodiment, the voltage divider circuit 1 includes a first resistor R1 and a second resistor R2.

In this embodiment, the power supply Vc is grounded to GND through the second resistor R2 and the first resistor R1, and the input voltage of the power supply Vc is divided through the first resistor R1 and the second resistor R2 connected in series.

In the embodiment, the first resistor R1 and the second resistor R2 connected in series are arranged to step down the input voltage of the power supply Vc, so as to prevent the RTC clock 3 from being burnt due to the excessive input voltage of the power supply Vc.

Optionally, the voltage of the power supply Vc is Vc, the resistance of the first resistor R1 is R1, and the resistance of the second resistor R2 is R2, and then the calculation formula of the output voltage vi (i.e., the voltage across the first resistor R1) of the power supply Vc after passing through the voltage dividing circuit 1 is as follows:

in addition, the resistance values of the first resistor R1 and the second resistor R2 can be determined according to the voltage required by the RTC clock 3 during normal operation.

Alternatively, r 1-499K Ω (unit: kilo-ohm), r 2-562K Ω, then

In order to further stabilize the divided voltage, the present embodiment can input the divided voltage obtained by the voltage dividing circuit 1 to the input terminal of the emitter follower circuit 2, further process the divided voltage through the emitter follower circuit 2, and output the stable divided voltage, thereby maintaining the normal operation of the RTC clock 3.

Alternatively, referring to fig. 2, the first resistor R1 has one end connected to the ground GND and the other end connected to the input end of the emitter follower circuit 2; the second resistor R2 has one end connected to the power supply Vc and the other end connected to the input end of the emitter follower circuit 2.

Of course, the voltage divider circuit 1 is not limited to the above embodiments, and for example, another resistor may be connected in series or in parallel between the first resistor R1 and the ground GND, another resistor may be connected in series or in parallel between the second resistor R2 and the power supply Vc, or another circuit or device capable of achieving voltage division may be selected.

Referring again to fig. 2, the emitter follower circuit 2 may comprise a transistor Q.

In this embodiment, the input terminal of the emitter follower circuit 2 is the base b of the transistor Q, and the output terminal of the emitter follower circuit 2 is the emitter e of the transistor Q. After the base b of the triode Q is connected to the output divided voltage of the voltage dividing circuit 1, the divided voltage input by the voltage dividing circuit 1 is stabilized based on the characteristics of high input impedance and low output impedance of the triode Q, and the emitter e of the triode Q outputs the stable divided voltage as the power supply voltage V of the RTC clock 3 to supply power to the RTC clock 3, so that the RTC clock 3 can be maintained to work normally.

Referring to fig. 3, the emitter follower circuit 2 may further include a third resistor R3.

Optionally, one end of the third resistor R3 is connected to the emitter e of the transistor Q, the other end is connected to the ground GND, and the output end of the emitter follower circuit 2 is the non-ground end of the third resistor R3.

Optionally, referring to fig. 2, one end of the third resistor R3 is connected to the emitter e of the transistor Q, and the other end of the third resistor R3 is connected to the first resistor R1 that is grounded after passing through the base b of the transistor Q, so that the emitter e of the transistor is grounded to GND after passing through the third resistor R3 and the first resistor R1, thereby maintaining the normal operation of the transistor Q.

In this embodiment, in order to enable the transistor Q to operate in a conducting state, a collector c of the transistor Q is connected to a voltage source. Further, to save resources and simplify the circuit structures of the voltage dividing circuit 2 and the emitter follower circuit 3, the voltage source is the power supply Vc. Of course, a resistor may also be connected in series between the power supply Vc and the collector c of the transistor Q.

The triode Q can be selected to be a PNP or NPN type triode. In this embodiment, the transistor Q is an NPN transistor. It should be noted that the triode Q of the emitter follower circuit 2 can also be selected as a PNP-type triode, and those skilled in the art can refer to the NPN-type triode of the present embodiment to appropriately deform the emitter follower circuit 2 of the present embodiment, and then combine with a voltage division circuit, so as to stably supply power to the RTC clock 3.

In addition, in order to suppress noise of the power supply voltage V output from the output terminal of the emitter follower circuit 2 and further stabilize the power supply voltage V output from the emitter follower circuit 2, thereby providing a stable operating voltage for the RTC clock 3 and maintaining the normal operation of the RTC clock 3, the output terminal of the emitter follower circuit 2 is grounded via the capacitor C1.

Referring to fig. 2 and 3, the emitter e of the transistor Q is grounded via the capacitor C1, and the power supply voltage V input to the power pin 31 of the RTC clock 3 is filtered through the capacitor C1, so that the power supply voltage V input to the RTC clock 3 is stabilized, and stable power supply of the RTC clock is realized.

In summary, in the RTC power supply circuit of the present invention, the voltage divider circuit 1 and the emitter follower circuit 2 are disposed between the power supply Vc and the power pin 31, the voltage divider circuit 1 divides the voltage to implement voltage reduction, and the divided voltage of the voltage divider circuit 1 is stabilized based on the characteristics of high input impedance and low output impedance of the emitter follower circuit 2, so as to provide a stable working voltage for the RTC clock 3; moreover, the voltage divider circuit 1 and the emitter follower circuit 2 are arranged between the power supply Vc and the power supply pin 31 of the RTC clock 3, and the voltages between the power supply Vc and the power supply pin 31 of the RTC clock 3 can be matched by the voltage divider circuit 1 and the emitter follower circuit 2; further, the voltage divider circuit 1 and the emitter follower circuit 2 of the present invention are simple in circuit elements, low in cost, and small in power consumption.

It should be noted that the RTC power supply circuit can be applied to structures such as remote controllers having RTC clocks to stably supply power to the RTC clocks in these structures.

The RTC power supply circuit is applied to the remote controller for further explanation in this embodiment.

Referring to fig. 4 and 5, the remote controller includes a processor, an RTC clock 3, and an RTC clock power supply circuit, wherein an output terminal of the RTC clock power supply circuit is connected to a power pin 31 of the RTC clock 3.

The processor may be an ARM (Advanced RISC Machines, RISC microprocessors), an AVR (RISC reduced instruction set high speed 8-bit single chip), or an ASIC (Application Specific Integrated Circuit) chip.

Alternatively, referring to FIG. 4, the processor and the RTC clock 3 are two separate parts. Optionally, referring to fig. 5, the RTC clock 3 is a part of the processor, and the RTC clock 3 is integrated on the processor.

The remote controller can be used for controlling the work of equipment such as unmanned vehicles, model cars, robots and the like. In this embodiment, the remote controller is configured to control the unmanned aerial vehicle, where the processor is communicatively connected to a control module disposed inside a fuselage of the unmanned aerial vehicle. It should be noted that although the UAV of the present embodiment may be described as a multi-rotor UAV, such description is not limiting and one skilled in the art will appreciate that any type of UAV may be suitable.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

The RTC clock power supply circuit comprises a power supply, and is characterized by also comprising a voltage division circuit and an emitter follower circuit;

the input end of the voltage division circuit is connected with the power supply, the power supply is divided and then output to the input end of the emitter follower circuit, and the output end of the emitter follower circuit is connected to a power pin of an RTC clock.
The RTC clock supply circuit of claim 1, wherein the voltage divider circuit comprises a first resistor and a second resistor.
The RTC clock supply circuit of claim 2, wherein said first resistor has one terminal connected to ground and the other terminal connected to the input terminal of said emitter follower circuit.
The RTC clock supply circuit of claim 2, wherein said second resistor is connected to said power supply at one end and to an input of said emitter follower circuit at the other end.
The RTC clock supply circuit of claim 1, wherein the emitter follower circuit comprises a transistor, the input of the emitter follower circuit being the base of the transistor, the output of the emitter follower circuit being the emitter of the transistor.
The RTC clock supply circuit of claim 5, wherein said emitter follower circuit further comprises a third resistor, one end of said third resistor being connected to the emitter of said transistor and the other end being connected to ground;

an output terminal of the emitter follower circuit is a non-ground terminal of the third resistor.
The RTC clock supply circuit of claim 6, wherein said another terminal of said third resistor is connected to a first resistor connected to ground through the base of said transistor.
The RTC clock supply circuit of claim 5, wherein the power supply is connected to the collector of the transistor.
The RTC clock supply circuit of claim 1, wherein the output of the emitter follower circuit is connected to ground via a capacitor.
The RTC clock supply circuit of claim 1, wherein the power supply is a battery.
The RTC clock supply circuit of claim 10, wherein the battery is a secondary battery.