CN218633902U

CN218633902U - Power-on automatic starting circuit for electronic equipment

Info

Publication number: CN218633902U
Application number: CN202223218008.4U
Authority: CN
Inventors: 苏晨
Original assignee: Vanstone Electronic Beijing Co Ltd
Current assignee: Vanstone Electronic Beijing Co Ltd
Priority date: 2022-11-29
Filing date: 2022-11-29
Publication date: 2023-03-14
Anticipated expiration: 2032-11-29

Abstract

The utility model discloses a power-on automatic starting circuit for electronic equipment, a battery module of the electronic equipment is connected with a divider resistor R1 after passing through a power supply key switch SW1 and is grounded through a divider resistor R6; the main control module is connected to the drain electrode of the field effect transistor Q1 through a divider resistor R2 and is connected to the base electrode of the triode Q2B through the divider resistor R2 and a divider resistor R7 in a voltage dividing mode; the main control module is connected to the grid electrode of the field effect transistor Q1 through a delay resistor R3 and a delay resistor R4, and the source electrode of the field effect transistor Q1 is grounded; the PWRKEY _ OUT pin of the main control module is connected to the collector of the triode Q2B; the PWRKEY _ IO pin of the main control module is connected with the backward flow prevention diode D1 through a resistor R5 and then connected with the base electrode of the triode Q2B, and the emitting electrode of the triode Q2B is grounded. The advantages are that: the starting circuit is suitable for the field of automatic starting work after power is on, and under the condition of abnormal power failure and abnormal power restoration, the electronic equipment can automatically start work in time, so that the loss caused by power failure or no need of plugging a charging wire is reduced or avoided.

Description

Power-on automatic starting circuit for electronic equipment

Technical Field

The utility model relates to an electronic equipment switching on and shutting down technical field especially relates to an automatic start circuit of last electricity for electronic equipment.

Background

The existing on-off scheme of a part of electronic equipment circuits is inserted for charging after a product is used up, but the equipment cannot be automatically started, so that a consumer can misunderstand whether the charging is carried out or not, because the insertion state is not prompted when no power is available, some situations can be caused because an interface is incompletely inserted, some situations can be caused because a power plug is not well inserted and no power is available, and the basic situations often occur, so that the time is often delayed.

And the power-on and power-off modes used by most of the intelligent devices realize the functions of power-on and power-off through manual key operation. However, some intelligent devices without direct intervention of workers, such as industrial monitoring, data detection, smart home and other devices which do not need to be attended by people, are generally not provided with a power-on key, and are automatically powered on by directly powering on a system. In order to realize the automatic power-on of the system, the existing technical scheme mostly adopts an integrated circuit to output a power-on signal, and the cost is very high. Therefore, the utility model provides a simple and easy automatic start circuit of going up electricity here, after the electricity was gone up to the system, can export start signal to the system immediately, after the system start-up, each partial circuit function of various signal control was exported again.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an automatic start circuit of last electricity for electronic equipment to solve the aforementioned problem that exists among the prior art.

In order to realize the purpose, the utility model adopts the technical scheme as follows:

a power-on automatic starting circuit for electronic equipment comprises a field effect transistor Q1, a triode Q2B, a power supply key switch SW1, a backflow prevention diode D1, a divider resistor R2, a delay resistor R3, a delay resistor R4, a resistor R5, a divider resistor R6, a divider resistor R7, a delay capacitor C1 and a decoupling capacitor C2; the battery voltage VBATTRY of a battery module of the electronic equipment is connected with the voltage dividing resistor R1 after passing through the power supply key switch SW1 and is grounded through the voltage dividing resistor R6; a power supply voltage VBUS of a main control module of the electronic equipment is connected to a drain electrode of the field effect tube Q1 through a divider resistor R2, and is connected to a base electrode of the triode Q2B through the divider resistor R2 and a divider resistor R7 in a voltage dividing mode; the voltage VDD _ EXT carried by a main control module of the electronic equipment is connected to the grid electrode of the field-effect tube Q1 through a delay resistor R3 and a delay resistor R4, the middle of the resistors R3 and R4 is connected with a delay capacitor C1 in parallel and then is grounded, and the source electrode of the field-effect tube Q1 is grounded; a PWRKEY _ OUT pin of a main control module of the electronic equipment is connected to a collector of the triode Q2B, and the collector of the triode Q2B is grounded after being connected with a decoupling resistor C2 in parallel; the PWRKEY _ IO pin of the main control module of the electronic equipment is connected with the backflow prevention diode D1 through the resistor R5 and then connected with the base electrode of the triode Q2B, and the emitting electrode of the triode Q2B is grounded.

The utility model has the advantages that: 1. the utility model provides a start circuit is fit for going up the field of electricity with regard to automatic start work, possesses the circuit simply, and the reliability is high, low cost's characteristics, resumes the power supply abnormal conditions again at unusual outage under, and electronic equipment can in time automatic start work, alleviates or avoids because the outage perhaps does not have the loss of inserting the production of charging wire. 2. The utility model discloses in the start circuit that comprises field effect transistor and triode and resistance-capacitance device compares with the last start of having MCU control, the device still less, and the structure is simpler, and stability is better than the MCU of complicacy needs software control IO circuit, and circuit design is simpler, and the start time is shorter, and the cost is still less under the high circumstances of reliability.

Drawings

Fig. 1 is a schematic structural diagram of a power-on circuit in an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the invention, are given by way of illustration only.

As shown in fig. 1, in the present embodiment, a power switch SW1, a back-flow prevention diode D1, a voltage dividing resistor R2, a delay resistor R3, a delay resistor R4, a resistor R5, a voltage dividing resistor R6, a voltage dividing resistor R7, a delay capacitor C1, and a decoupling capacitor C2 are provided; the battery voltage VBATTRY of a battery module of the electronic equipment is connected with the voltage dividing resistor R1 after passing through the power supply key switch SW1 and is grounded through the voltage dividing resistor R6; a power supply voltage VBUS of a main control module of the electronic equipment is connected to a drain electrode of the field effect tube Q1 through a divider resistor R2, and is connected to a base electrode of the triode Q2B through the divider resistor R2 and a divider resistor R7 in a voltage dividing mode; the voltage VDD _ EXT carried by a main control module of the electronic equipment is connected to the grid electrode of the field-effect tube Q1 through a delay resistor R3 and a delay resistor R4, the middle of the resistors R3 and R4 is connected with a delay capacitor C1 in parallel and then is grounded, and the source electrode of the field-effect tube Q1 is grounded; a PWRKEY _ OUT pin of a main control module of the electronic equipment is connected to a collector of the triode Q2B, and the collector of the triode Q2B is grounded after being connected in parallel with the decoupling resistor C2; the PWRKEY _ IO pin of the main control module of the electronic equipment is connected with the backflow prevention diode D1 through the resistor R5 and then connected with the base electrode of the triode Q2B, and the emitting electrode of the triode Q2B is grounded.

In this embodiment, the operation of the boot circuit is as follows,

(1) In the boot state:

when the electronic equipment is inserted into an external charging wire, VBUS is electrified, VDD _ EXT is provided by a circuit module of the electronic equipment after the electronic equipment is started, in the starting state, VDD _ EXT is in a voltage state, a field effect tube Q1 is conducted, a source electrode and a drain electrode are conducted and pulled down to the ground, one end of a divider resistor R7 is pulled down, a base electrode of a triode Q2B is in a low level state, the triode Q2B is not conducted, a PWRKEY _ OUT pin is kept in an original state, and a main control module of the electronic equipment normally works without power failure;

when a power key switch SW1 of the electronic equipment is pressed, after voltage is divided by a divider resistor R1 and a divider resistor R6, the base voltage of a triode Q2B is high, the triode Q2B is conducted, a collector and an emitter of the triode Q2B are pulled down, a PWRKEY _ OUT pin is pulled down, and a main control module of the electronic equipment is shut down;

(2) In the shutdown state:

when the electronic equipment is inserted into an external charging wire, VBUS is electrified, the base voltage of a triode Q2B is pulled high through a divider resistor R7, the collector and the emitter of the triode Q2B are conducted, the PWRKEY _ OUT pin is set to be low and grounded, the POWKEY _ OUT pin is pulled low, and the main control module of the electronic equipment can realize automatic startup after a first preset time (2 s); after a main control module of the electronic equipment is started, VDD _ EXT is electrified, the electrification delay is carried OUT through a delay resistor R3, a delay resistor R4 and a delay capacitor C1, the conduction is normally carried OUT after the delay for a second preset time (more than one second, here, only one time interval is carried OUT before and after), a source electrode and a drain electrode of a field effect tube Q1 are conducted, VBUS is conducted and pulled down to the ground through a divider resistor R2 and the source electrode and the drain electrode of the field effect tube Q1, the base voltage connected with a triode Q2B is low, the base electrode of the triode Q2B is not acted, the triode Q2B is not conducted, a PWRKEY _ OUT pin is not pulled down, and the on-off is not influenced;

when a power key switch SW1 is pressed, the voltage of the positive electrode of a backflow prevention diode D1 is changed from low to high, the voltage of the base electrode of a triode Q2B is high, the triode Q2B is conducted, the conduction of the collector and the emitter of the triode Q2B is pulled low, the pin PWEKEY _ OUT is low, and the main control module of the electronic equipment can be automatically started after a first preset time (2 s);

when the power key switch SW1 is pressed, the main control module of the electronic equipment is automatically started after the first preset time (2 s), VDD _ EXT is electrified, at the moment, if the electronic equipment is inserted into an external charging wire, the grid electrode of the field effect tube Q1 is in a voltage state due to VDD _ EXT, a source electrode and a drain electrode are conducted, the base voltages of the divider resistors R1 and R6 and the triode Q2B are low, the emitting electrode and the collector electrode of the triode Q2B are not conducted, the PWRKEY _ OUT pin cannot be lowered, and the on-off state of the main control module of the electronic equipment is not influenced by the insertion of the external charging wire.

In this embodiment, the operating principle of the boot circuit is as follows:

when the power key switch SW1 is not pressed, the divider resistor R1 is connected to the ground through the divider resistor R6, the positive electrode of the backflow prevention diode D1 is at the ground level of 0, the base voltage of the triode Q2B is grounded to be low through the divider resistor R7, the collector and the emitter of the triode Q2B are not conducted, and the PWRKEY _ OUT pin is connected with the triode Q2B and is in a high-resistance state.

When a power supply starting key of the electronic equipment is pressed down, the voltage dividing resistor R1 is connected with the battery voltage VBATTRY of a battery module of the electronic equipment, after the voltage dividing resistor R1 and the voltage dividing resistor R6 are divided, the voltage of an anode of the backflow prevention diode D1 is about 2V and is larger than the starting voltage from a base level to an emitting level of the triode Q2B, the conducting voltage of a collector and an emitter of the triode Q2B is lowered, and after a PWRKEY _ OUT pin is pulled down for a first preset time (2 s), a main control module of the electronic equipment can be started.

In this embodiment, the voltage of the PWR _ KEY _ IO pin at the midpoint between the voltage dividing resistor R1 and the voltage dividing resistor R6 is low, and if the power KEY switch SW1 of the electronic device is pressed, the voltage is high and is about half 1.9V of the battery voltage VBATRRY (3.8V), and since the voltage output from the PWR _ KEY _ IO pin is 1.8V, the voltage dividing is performed by the voltage dividing resistor R1 and the voltage dividing resistor R6, and the resistance values of the two resistors are both identical to 10K.

The VDD _ EXT voltage controls the on-off of the field effect transistor Q1 through the delay resistor R3 and the delay resistor R4, the source electrode of the field effect transistor Q1 is grounded, and the delay capacitor C1, the delay resistor R3 and the delay resistor R4 are charged and discharged together to play a role in buffering on-off.

The main control module of the electronic equipment is started, and the PWR _ KEY _ IO pin is connected to the anode of the backflow prevention diode D1 through the resistor R5 and then connected to the base electrode of the triode Q2B to control the connection or the connection and the disconnection of the emitter and the collector of the triode Q2B.

The negative electrode of the anti-backflow diode D1 is connected to the VBUS through the voltage dividing resistor R2, so that when the VBUS has voltage, the negative electrode of the anti-backflow diode D1 is connected to the VBUS, current cannot flow from the negative electrode to the positive electrode of the anti-backflow diode D1 through the resistor R5 to the PWR _ KEY _ IO pin, and voltage change of the PWR _ KEY _ IO pin cannot be caused.

Because coupling capacitors are arranged between the collector and the emitter of the triode Q2B, generally at the pf level, the capacitor C2 has the function of increasing the interelectrode capacitance, reducing the high-frequency characteristic of the triode Q2B and avoiding self-oscillation. Due to the sensitive power key switch SW1 connected here, it is necessary to reduce possible glitches. And because the power supply key switch SW1 is a power on/off key, a stable power on/off instruction needs to be obtained, a mistaken trigger signal caused by the fact that a user carelessly touches the power on/off key for a short time is avoided, a certain power on/off information needs to be obtained, after the decoupling capacitor C2 is set, an ascending signal becomes slow, voltage stabilization is facilitated, and only a certain long-time pressing is carried out, the power on/off instruction is defaulted to be the power on/off instruction.

Through adopting the utility model discloses an above-mentioned technical scheme has obtained following profitable effect:

the utility model provides an automatic start circuit of last electricity for electronic equipment, the utility model provides a start circuit is fit for the field of the work of just automatic start of last electricity, possesses the circuit simply, and the reliability is high, low cost's characteristics resume the power supply abnormal conditions again at the abnormal power failure under, and electronic equipment can in time automatic start work, alleviates or avoids because the loss that the charging wire produced is perhaps not had to be inserted to the outage. The utility model discloses in the start circuit that comprises field effect transistor and triode and resistance-capacitance device compares with the last start of having MCU control, the device still less, and the structure is simpler, and stability is better than the MCU of complicacy needs software control IO circuit, and circuit design is simpler, and the start time is shorter, and the cost is still less under the high circumstances of reliability.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be viewed as the protection scope of the present invention.

Claims

1. A power-on auto-start circuit for an electronic device, comprising: the circuit comprises a field effect transistor Q1, a triode Q2B, a power supply key switch SW1, a backflow prevention diode D1, a divider resistor R2, a delay resistor R3, a delay resistor R4, a resistor R5, a divider resistor R6, a divider resistor R7, a delay capacitor C1 and a decoupling capacitor C2; the battery voltage VBATTRY of a battery module of the electronic equipment is connected with the divider resistor R1 after passing through the power supply key switch SW1 and is grounded through the divider resistor R6; a power supply voltage VBUS of a main control module of the electronic equipment is connected to a drain electrode of the field effect tube Q1 through a divider resistor R2, and is connected to a base electrode of the triode Q2B through the divider resistor R2 and a divider resistor R7 in a voltage dividing mode; the voltage VDD _ EXT carried by a main control module of the electronic equipment is connected to the grid electrode of the field-effect tube Q1 through a delay resistor R3 and a delay resistor R4, the middle of the resistors R3 and R4 is connected with a delay capacitor C1 in parallel and then is grounded, and the source electrode of the field-effect tube Q1 is grounded; a PWRKEY _ OUT pin of a main control module of the electronic equipment is connected to a collector of the triode Q2B, and the collector of the triode Q2B is grounded after being connected with a decoupling resistor C2 in parallel; the PWRKEY _ IO pin of the main control module of the electronic equipment is connected with the backflow prevention diode D1 through the resistor R5 and then connected with the base electrode of the triode Q2B, and the emitting electrode of the triode Q2B is grounded.