CN111524337A

CN111524337A - Low standby power consumption transmitter powered by single-node one-point five-volt battery

Info

Publication number: CN111524337A
Application number: CN201911305171.4A
Authority: CN
Inventors: 覃康健; 谭琦
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-02-01
Filing date: 2019-12-17
Publication date: 2020-08-11
Also published as: CN210836531U

Abstract

A low standby power consumption transmitter powered by a single 1.5V battery. The emitter comprises a single 1.5V battery, a booster circuit, a key, a singlechip and an emitting circuit. The enabling end of the booster circuit is connected to the single chip microcomputer, when the single chip microcomputer outputs a high level to the enabling end of the booster circuit, the booster circuit is in a working state, and when the single chip microcomputer outputs a low level to the enabling end of the booster circuit, the booster circuit is in a stop working state. The boosting circuit is provided with a voltage division circuit controlled by the single chip microcomputer, when the single chip microcomputer outputs a high level to the voltage division circuit, the boosting circuit outputs 2.5V voltage, and when the single chip microcomputer outputs a low level to the voltage division circuit, the boosting circuit outputs 3.3V voltage. The working voltage of the emitter is 2.5V and is in a low power consumption state when the emitter is in standby, and the working voltage of the emitter is 3.3V and is in a high power consumption state when the emitter is in emission.

Description

Low standby power consumption transmitter powered by single-node one-point five-volt battery

Technical Field

The invention relates to the technical field of electronics, in particular to a low-standby-power-consumption transmitter powered by a single 1.5V battery.

Background

At present, a single-section 1.5V battery-powered transmitter generally uses a booster circuit with fixed output voltage; when some transmitters do not transmit signals, the booster circuit is in a continuous working state, and the standby power consumption of the booster circuit is larger; in order to reduce standby power consumption of some transmitters, a mechanical switch is additionally arranged between a battery and a booster circuit to control the on-off of a power supply, and when the transmitters are not used, the power supply of the transmitters needs to be manually disconnected to reduce the standby power consumption; some transmitters use a mechanical switch to control an enabling end of the booster circuit, the booster circuit works by manually switching on the mechanical switch when the transmitters are used, and the booster circuit stops working by manually switching off the mechanical switch when the transmitters are not used, so that the standby power consumption can be reduced. Above-mentioned first kind of transmitter, during not transmitting signal, boost circuit is in operating condition all the time, and boost circuit self standby power consumption is great to can't reduce boost circuit's output voltage, each partial circuit static power consumption of transmitter is often great under the high voltage state, so the transmitter does not transmit signal during battery power consumption very fast, has shortened the life of battery. When the two latter transmitters are used up, the phenomenon that the mechanical switch is forgotten to be switched off occurs, so that the standby power consumption of the transmitters is increased when the transmitters are idle, and the mechanical switch needs to be forgotten to be switched off after the transmitters are used up, so that the use is inconvenient. In summary, the conventional transmitter powered by a single 1.5V battery cannot simultaneously achieve low standby power consumption and convenience in use.

Disclosure of Invention

In order to overcome the defect that the existing transmitter powered by a single 1.5V battery cannot simultaneously give consideration to low standby power consumption and use convenience, the invention provides the transmitter powered by the single 1.5V battery and having low standby power consumption.

The technical scheme adopted by the invention for solving the technical problems is as follows: the emitter comprises a single 1.5V battery, a booster circuit with an enabling end and an output voltage capable of being switched between 2.5V and 3.3V, a key, a singlechip and an emitting circuit. During the period of not transmitting signals, the output voltage of the booster circuit is reduced as much as possible, the working time of the booster circuit is reduced as much as possible, the time of the single chip microcomputer in the awakening state is reduced as much as possible, and the standby power consumption of the transmitter can be obviously reduced. During the period of not transmitting signals, the single chip microcomputer is used for controlling the enabling end of the booster circuit instead of manually controlling the enabling end of the booster circuit through the mechanical switch, so that the problem that the standby power consumption of the transmitter is increased due to the fact that a user forgets to switch off the mechanical switch is avoided, and convenience in use is brought.

Drawings

Fig. 1 is a schematic block diagram of the present invention.

Fig. 2 is a circuit schematic of the present invention.

Fig. 3 is an internal block diagram of the boost IC QX2303L 25F.

Fig. 4 is a schematic diagram of a booster circuit with an output voltage of 2.5V.

Fig. 5 is a schematic diagram of a boost circuit with an output voltage of 3.3V.

Detailed Description

The principle block diagram of the invention is shown in the attached figure 1. The invention consists of a single 1.5V battery, a booster circuit with an enabling end and an output voltage capable of being switched between 2.5V and 3.3V, a key, a singlechip and a transmitting circuit. The boosting circuit boosts the voltage of the 1.5V battery to the working voltage required by the single chip microcomputer and the transmitting circuit; the booster circuit is provided with an enabling end, the booster circuit is in a continuous working state when the enabling end is at a high level, and the booster circuit is in a stop working state when the enabling end is at a low level; the output voltage of the boost circuit is dynamically changeable, and in order to reduce power consumption in a standby state without transmitting signals, the voltage of 2.5V is selected to be output, and since the maximum output power of the transmitting IC SYN115 used in the embodiment is reduced along with the reduction of the power supply voltage, the voltage of 3.3V is selected to be output in order to ensure that the transmitting power is large enough in the process of transmitting signals. The single chip microcomputer has five functions, wherein the first function is power-on initialization, the second function is detecting whether a key is pressed down, the third function is controlling the booster circuit to be in a working state or a stop working state, the fourth function is selecting the booster circuit to output 2.5V or 3.3V voltage, and the fifth function is providing a modulation signal for the transmitting circuit. The press key converts the press operation into a voltage signal which can be recognized by the singlechip. The transmitting circuit converts the modulation signal provided by the singlechip into a radio frequency signal to be transmitted.

In the embodiment shown in fig. 2, the positive electrode of the battery is connected to the enable terminal of the boost circuit (i.e., pin 1 of IC 1) through resistor R1, the enable terminal voltage is greater than 0.8V after the battery is mounted, and the boost circuit immediately enters an operating state and outputs 2.5V. Pin 2 of the monolithic IC2 is also connected to the enable terminal of the boost circuit (i.e., pin 1 of the IC 1), and when pin 2 of the monolithic IC2 outputs a high level, the boost circuit is in an operating state, and when pin 2 of the monolithic IC2 outputs a low level, the boost circuit is in a stop operating state. The type of the used boost IC is QX2303L25F, the internal block diagram of the QX2303L25F is shown in FIG. 3, and it can be seen from the internal block diagram of the QX2303L25F that VOUT is actually the voltage feedback input end of the boost circuit. Calculation based on the specification of QX2303L25F and actual testing of the samples led to an input resistance between VOUT and GND of approximately 400K, and the feature that the input resistance between VOUT and GND was high was utilized in later demonstration of the feasibility of extending the voltage of the booster circuit to 3.3V. The output VCC of the boost circuit is connected with the voltage feedback input end of the boost circuit, namely pin 2 of IC1, through a resistor R2, and pin 2 of IC1 is connected with pin 3 of the singlechip IC2 through a resistor R3. When pin 3 of the single chip IC2 outputs a high level, the equivalent circuit is as shown in fig. 4, at this time, VCC and VOUT of the IC1 are connected together through a resistance of 750 ohms, and since the resistance between VOUT of the IC1 and GND is about 400K, which is much greater than 750 ohms, the voltage at the VCC point is very close to the voltage at the VOUT point, and the output voltage of the boost circuit is very close to 2.5V. When pin 3 of the single chip IC2 outputs a low level, the equivalent circuit is as shown in fig. 5, because the input resistance between VOUT of the IC1 and GND is about 400K, which is much greater than 1K and 3K, the voltage division ratio of the resistors R2 and R3 is 3: 4, the output voltage of the booster circuit is expanded to 3.3V.

In the embodiment shown in fig. 2, after the transmitter is equipped with a 1.5V battery, the booster circuit immediately enters a working state and outputs 2.5V voltage, the single chip microcomputer enters a power-on reset state, after the reset is finished, the single chip microcomputer starts to operate a power-on initialization program, pin 2 of the single chip microcomputer IC2 outputs high level, pin 3 of the single chip microcomputer IC2 also outputs high level, that is, the booster circuit keeps working and continues to output 2.5V voltage, and the initialization state is finished after being maintained for 1 second.

After the initialization is completed, the single chip microcomputer enters an awakening state 1. After the mobile phone enters the awakening state 1, if no key is pressed down, the single chip microcomputer immediately executes the following four operation steps: step one, a pin 2 of the singlechip IC2 outputs a low level to stop the booster circuit, and a pin 3 of the singlechip IC2 keeps outputting a high level to avoid the divider resistor R3 from consuming current; step two, starting a low-power-consumption timer to set the timing time to 750 ms; enabling a key awakening function; and step four, entering a sleep state. The total time required for executing the four operation steps is less than 0.1ms, and after the four operation steps are executed, the single chip microcomputer enters a sleep state 1. After the single chip microcomputer enters the sleep state 1, if no key is pressed down, the single chip microcomputer is awakened through the low-power-consumption timer of 750ms, and the single chip microcomputer enters the awakening state 2. After entering the awakening state 2, if no key is pressed down, the singlechip immediately executes the following four operation steps: step one, pin 2 of the singlechip IC2 outputs high level, pin 3 of the IC2 maintains outputting high level, namely the singlechip controls the booster circuit to enter a working state and output 2.5V voltage; step two, starting a low-power-consumption timer to set the timing time to be 4.5 ms; enabling a key awakening function; and step four, entering a sleep state. The total time required for executing the four operation steps is less than 0.1ms, and after the four operation steps are executed, the single chip microcomputer enters a sleep state 2. After the single-chip microcomputer enters the sleep state 2, if no key is pressed down, the single-chip microcomputer is awakened through the 4.5ms low-power-consumption timer, the single-chip microcomputer enters the awakening state 1 again, and a new cycle of circulation is started.

After the sleep state 1 is entered, the booster circuit stops working, the single chip microcomputer IC2 supplies power by using the charges on the 47uF capacitor E1, the current consumed by the booster IC is less than 1uA, the current consumed by the single chip microcomputer is less than 0.4uA, the total current consumed by the emitter is less than 1.4uA, and the voltage on the capacitor E1 is reduced within 750ms by the following amplitude: Δ U = Δ Q ÷ C = I × Δ t ÷ C =1.4uA × 750ms ÷ 47uF ≈ 22.3mV, the voltage drop is negligible.

In the sleep state 1 or the sleep state 2, if a key is pressed down, the singlechip is immediately awakened and enters a key jitter elimination processing process; in the awakening state 1 or the awakening state 2, if a key is pressed down, the single chip microcomputer immediately enters a key shake elimination processing process. After the key jitter elimination, pin 2 of the singlechip IC2 outputs high level, and pin 3 of the IC2 outputs low level, that is, the booster circuit enters a working state, outputs 3.3V voltage, and then transmits a signal. After the emission signal is finished, a pin 3 of the IC2 outputs a high level to enable the booster circuit to output 2.5V voltage, the single chip microcomputer returns to the awakening state 1, and then the single chip microcomputer circularly works according to the sequence of the awakening state 1, the sleeping state 1, the awakening state 2 and the sleeping state 2.

In a standby state, the output voltage of the booster circuit is 2.5V, and the emitter is in a wake-up state 1, a sleep state 1, a wake-up state 2 and a sleep state 2 in turn. If no key is pressed, the sleep state 1 lasts 750ms, and in the sleep state 1, the booster circuit is in a stop working state, and the current consumed by the booster circuit is less than 1 uA. If no key is pressed, the duration time of the sleep state 2 is 4.5ms, and in the sleep state 2, the booster circuit is in a working state, and the current consumed by the booster circuit is 15 uA. The duration of the wake-up state 1 and the wake-up state 2 is less than 0.1ms, which can be ignored, so the average standby current of the boost circuit itself is:

I1≈(1uA×750ms +15uA×4.5ms) ÷(750ms+4.5ms)≈1uA (1)

in a standby state, the duration time of a sleep state 1 is 750ms, the duration time of a sleep state 2 is 4.5ms, the consumed current of the single chip microcomputer during sleep is less than 0.4uA, the duration time of an awakening state 1 and the duration time of the awakening state 2 are less than 0.1ms, the duration time of the awakening state in each cycle period is less than 0.2ms in total, and the consumed current of the single chip microcomputer during awakening is 340 uA. Therefore, the average standby current of the single chip microcomputer is as follows:

I2≈(0.4uA×750ms+0.4uA×4.5ms+340uA×0.2ms)÷(750ms+4.5ms+0.2ms)≈0.5uA (2)

the average voltage of the battery is about 1.25V in the using process, the output voltage of the booster circuit is 2.5V in the standby state, the efficiency of the used booster circuit is about 75%, and the average standby current I2 of the single chip microcomputer is converted into the input end of the booster circuit as follows:

I3=I2×2.5÷1.25÷75%≈0.5×2.5÷1.25÷75%≈1.33uA (3)

in the standby state, the average current of the transmitter is:

I4=I1+I3≈1uA+1.33uA=2.33uA (4)

in this embodiment, a manchester coding and ASK modulation mode is used, when each bit is transmitted, a carrier wave is transmitted outwards in half time, the transmission of the carrier wave is stopped in half time, when the transmission circuit continuously transmits the carrier wave, the current is 18mA, and when the transmitter transmits an ASK signal, the average current of the transmission circuit is:

I5≈18mA×50%=9mA (5)

when the device is used, the average voltage of the battery is about 1.25V, the output voltage of the booster circuit is 3.3V when the emitter emits signals, the efficiency of the used booster circuit is about 75%, and the average current I5 of the emitter circuit is converted to the input end of the booster circuit as follows:

I6≈9mA×3.3V÷1.25V÷75%≈32mA (6)

the duration of the ASK signal transmitted by the present embodiment is 200mS, and under the condition that the transmitter key is pressed 40 times per day, the average current consumed by the transmitting circuit is:

I7≈32mA×200mS×40÷24÷3600S≈2.96uA (7)

with the transmitter key pressed 40 times per day, the average current of the transmitter is:

I8=I4+I7≈2.33uA+2.96A=5.29uA (8)

the capacity of a No. 7 1.5V alkaline or lithium iron battery is about 1100mAH, and the theoretical service time is as follows:

t1=1100mAH ÷ 5.29uA ≈ 207939 h ≈ 23.7 years (9)

The capacity of a No. 5 1.5V alkaline battery or a lithium iron battery is more than twice of that of a No. 7 battery, and the service life is more than 47 years theoretically.

The shelf life of a 1.5V alkaline battery or a lithium iron battery with long shelf life is 10 years, so the actual service life exceeds 10 years.

If the technical scheme of the invention is not adopted, but a scheme that the booster circuit is in a continuous working state and the output voltage is fixed to be 3.3V is adopted during the period of not transmitting signals, the booster circuit is continuously in the working state, and the power-direct current consumed by the booster circuit is 15uA, so that the average current consumed by the booster circuit is increased to be as follows:

I9=15uA (10)

if the technical scheme of the invention is not adopted, but a scheme that the boosting circuit is in a continuous working state and the output voltage is fixed to be 3.3V is adopted during the period of not transmitting signals, the sleeping current of the singlechip is increased to be 0.8uA, the average voltage of a battery is about 1.25V in the using process, the output voltage of the boosting circuit is 3.3V in the standby state, the efficiency of the used boosting circuit is about 75 percent, and therefore the average standby current of the singlechip is converted to the input end of the boosting circuit and is increased to be as follows:

I10=0.8uA×3.3÷1.25÷75%≈2.82uA (11)

if the technical scheme of the invention is not adopted, but the scheme that the booster circuit is in a continuous working state and the output voltage is fixed to be 3.3V during the period of not transmitting signals is adopted, in a standby state, the average current of the transmitter is increased to be as follows:

I11=I9+I10≈15uA+2.82uA=17.82uA (12)

according to the formula (4), when the technical scheme of the present invention is adopted, the average current of the transmitter in the standby state is I4=2.33uA, so the standby current saved by the technical scheme of the present invention is about:

I12=I11－I4=17.82uA－2.33A=15.49uA (13)

if the scheme that the boosting circuit is in a continuous working state and the output voltage is fixed to be 3.3V during the period of not transmitting the signal is adopted, the current consumed by the transmitting circuit in the transmitting state is the same as the technical scheme of the invention, and under the same condition that the transmitter key is pressed 40 times per day, the average current consumed by the transmitting circuit is still I7=2.96uA according to the formula (7), so that the average current of the transmitter is as follows:

I13≈ I11+I7=17.82uA+2.96uA=20.78uA (14)

if a scheme that the boosting circuit is in a continuous working state and the output voltage is fixed to be 3.3V during the period of not transmitting signals is adopted, a No. 7 1.5V alkaline or lithium iron battery with the capacity of about 1100mAH is used, and the service time is theoretically:

t2=1100mAH ÷ 20.78uA ≈ 52936 h ≈ 6 years (15)

Is much less than 23.7 years of formula (9).

Therefore, compared with the scheme that the booster circuit is in a continuous working state and the output voltage is fixed to be 3.3V during the period of not transmitting signals, the service life of the battery is obviously prolonged. Meanwhile, the invention can enter the standby state with extremely low power consumption without disconnecting the mechanical switch by a user, thereby realizing the convenience of use.

Claims

1. The utility model provides a low stand-by power consumption transmitter of single section 1.5V battery power supply, comprises single section 1.5V battery, boost circuit, button, singlechip and transmitting circuit, its characterized in that: the enable end of the boost circuit, namely pin 1 of the IC1, is connected to the positive electrode of the battery BT1 through a resistor R1, meanwhile pin 1 of the IC1 is connected to an IO port of the single chip microcomputer, namely pin 2 of the IC2, the output end VCC of the boost circuit and pin 2 of the IC1 are connected together through a resistor R2, and pin 2 of the IC1 and another IO port of the single chip microcomputer, namely pin 3 of the IC2, are connected together through a resistor R3.