JP5455826B2 - Power-on control circuit - Google Patents

Description

  The present invention relates to a power-on control circuit, and more particularly, when a power supply or an electronic circuit of an information processing apparatus has a failure, the power supply is stopped immediately after the power is turned on, thereby protecting the apparatus and ensuring safety. The present invention relates to a power-on control circuit that can be used.

  In recent years, electronic circuits such as a personal computer (PC) motherboard and peripheral devices are operated by various types of DC power supplies. For this reason, a PC or the like is usually provided with a power supply device that supplies a plurality of DC power supplies, and a plurality of power supplies are supplied from the power supply device to each electronic circuit that is a load. ATX power supplies (see ATX Specification Version 2.2 and ATX12V Power Supply Design Guide Version 2.2) are widely known as power supply units used for this purpose. Microprocessors and memories on motherboards and peripheral circuits, input / output, video Power is supplied to the hard disk drive and the like. Furthermore, dedicated power supply systems are often provided for each part of the circuit by further reducing the DC power supplied from the power supply device.

  When a plurality of DC power supplies (voltage sources) are used, there is a problem of protection of an electronic circuit when a failure occurs in a power supply device or a circuit serving as a load. For example, in a circuit to which voltage is to be applied from a plurality of voltage sources, if no voltage is applied from at least one of the voltage sources, an undesired voltage is applied to the circuit and the circuit is destroyed. There is a problem. In order to suppress the breakdown of this circuit, it is determined whether or not voltage can be applied to the circuit from each voltage source based on whether or not the voltage value is a certain value or more. A circuit protection device that prevents voltage application to the circuit when it is determined that the circuit is not used (see Patent Document 1).

  In addition, there is a method of determining a failure of the device by monitoring the power-on processing time of the device. For example, in an information processing system composed of a plurality of devices, each device is monitored for the power-on processing time from power-on to the end of the power-on operation, and the power-on processing time is measured from the stored normal power-on processing time A power-on monitoring system that determines that a device is abnormal when a value becomes large is disclosed (see Patent Document 2).

JP 2006-311773 A JP-A-2-266410

As described above, protection is provided when a failure occurs in any part of the power supply device and the electronic circuit provided in the PC or the like as the power supply used in the electronic circuit in the information processing device such as the PC becomes more various. Safety is an important issue. This is because an electronic circuit is not only destroyed due to a failure, but an accident such as smoke or ignition of a used part may be caused.
By using the circuit protection device disclosed in Patent Document 1, it is possible to prevent the circuit from being destroyed due to an undesired power supply being applied to a circuit using a plurality of power supplies. However, in order to ensure safety at the time of failure for various circuits, a widely applicable technique is required.
Further, as described in Patent Document 2, a failure of the apparatus can be recognized by monitoring the power-on processing time from when the information processing apparatus is turned on until the end of the power-on operation. However, for the purpose of preventing smoke and fire due to a failure of the electronic circuit in the device, it is necessary to detect the abnormality in the device in the shortest time and immediately turn off the power when the abnormality is detected. is necessary.
Failures can occur in any part of the power supply and electronic circuitry, and the manner of failure varies. When an abnormal current is generated in an electronic circuit due to a failure, smoke or fire may be caused in a very short time (for example, about 1 second). Therefore, immediately after the power is turned on, it is generally required to immediately stop the power supply to the electronic circuit when there is a possibility of failure at the initialization stage of the electronic circuit.

  In view of the above problems, the present invention can protect and protect the device by stopping the power supply immediately after the power is turned on when the power supply or electronic circuit of the information processing device is faulty. An object is to provide a power-on control circuit.

In order to solve the above-mentioned problems, the first invention is connected to a power supply device that supplies a DC power supply in accordance with an input power-on signal, and the power supply provided in a load circuit that receives the supply of the DC power supply as a main power supply A control circuit that outputs the power-on signal to the power supply device; a timer that starts timing when the power-on signal is activated; and the voltage of the main power supply is a specified voltage. A main power supply monitoring circuit for outputting a main power supply normal signal when the main power supply normal signal is not output from the main power supply monitoring circuit before the predetermined time is counted by the timer, stopping the supply of the DC power source to the power supply by a power-on signal inactive, further a second timer which starts clocking when the voltage of the main power source exceeds a predetermined value If the main power supply normal signal is not output from the main power supply monitoring circuit before the predetermined time is counted by the second timer, the power supply device is deactivated to deactivate the power supply device. The main point is to stop the supply of the DC power.

According to a second aspect of the present invention, there is provided a power-on control circuit provided in a load circuit that is connected to a power supply device that supplies DC power in accordance with an input power-on signal and that is supplied with the DC power as a main power supply. An output circuit that outputs the power-on signal, a timer that starts timing when the power-on signal is activated, and a main power normal signal that is output when the voltage of the main power is a specified voltage A main power supply monitoring circuit, and if the main power supply normal signal is not output from the main power supply monitoring circuit before the predetermined time is counted by the timer, the power-on signal is deactivated. the power supply device supplying the DC power supply is stopped, the said load circuit has one or more of the sub-power supply for outputting a separate DC power supply is provided by receiving the supply of the main power supply by A second timer that starts timing when the voltage of the main power source exceeds a predetermined value; and a sub power source that outputs a sub power source normal signal for the sub power source when the output voltage of each sub power source is a specified voltage A monitoring circuit, and when the sub power supply normal signal is not output from at least one of the sub power supply monitoring circuits before the predetermined time is counted by the second timer, the power on signal is The gist is to stop the supply of the DC power to the power supply device by deactivating it.
According to a third aspect , in the second aspect , when the main power supply normal signal is not output from the main power supply monitoring circuit before the predetermined time is counted by the second timer, the power supply The gist is to stop the supply of the DC power to the power supply device by deactivating the input signal.

According to a fourth invention, in any one of the first to third inventions, the second timer includes a logic circuit element to which a voltage proportional to the voltage of the main power supply is input, and the logic circuit element is used as the predetermined value. The gist is to use the threshold value.

According to a fifth invention, in any one of the first to fourth inventions, the power supply device includes a power supply normal signal output indicating that the supplied DC power supply has a specified voltage, The power supply monitoring circuit uses the power supply normal signal output from the power supply device as the main power supply normal signal.

According to the power-on control circuit of the first aspect of the present invention, there is provided a power-on control circuit that is connected to a power supply device that supplies DC power in accordance with a power-on signal, and that is provided in a load circuit that receives supply of the DC power as main power. An output circuit that outputs a power-on signal to the power supply, a timer that starts timing when the power-on signal is activated, and a main power that outputs a main power normal signal when the main power is at a specified voltage And when the main power normal signal is not output before the predetermined time is counted by the timer, the power supply signal is deactivated to stop the supply of DC power to the power supply device. Therefore, it is possible to detect abnormalities in the power supply system with the shortest energization time to the load circuit, and even if there is an unexpected failure, the load circuit smokes or ignites, regardless of the location of the failure. It is possible to prevent late. In addition, a circuit can be easily configured with a small number of components, and complicated control processing is not required.
And a second timer for starting timing when the voltage of the main power source exceeds a predetermined value, and when the main power normal signal is not output before the predetermined time is counted by the second timer. Since the power-on signal is deactivated, an abnormality in the power supply system can be accurately detected in the shortest time after the voltage of the main power supply exceeds the predetermined value and starts to rise. That is, there is a low possibility of causing an accident such as smoke or fire before the main power source starts to rise. Also, for example, when the time from when the power is turned off to when the power is turned on next is short, the capacitance existing in the power supply circuit is not discharged. The time varies greatly depending on the power-on state. Therefore, the fluctuation can be eliminated by starting from the rise start of the main power supply, and the presence or absence of abnormality can be detected accurately and in the shortest time.

According to the second invention, there is provided a power-on control circuit that is connected to a power supply device that supplies a DC power supply in accordance with a power-on signal and is provided in a load circuit that receives the supply of the DC power supply as a main power supply. An output circuit that outputs a power-on signal, a timer that starts timing when the power-on signal is activated, and a main power monitoring circuit that outputs a main power normal signal when the main power is at a specified voltage, If the main power supply normal signal is not output by the time measured by the timer, the power supply signal is deactivated to stop the DC power supply from being supplied to the load circuit. It is possible to detect abnormalities in the power supply system with the shortest energization time, and to prevent accidents such as smoke or ignition of the load circuit even if there is an unexpected failure, regardless of the location of the failure Possible to become. In addition, a circuit can be easily configured with a small number of components, and complicated control processing is not required.
In addition, the load circuit is provided with one or more sub power supplies that receive the main power supply and output another DC power supply, and start timing when the voltage of the main power supply exceeds a predetermined value. And a secondary power supply monitoring circuit that outputs a secondary power supply normal signal for the secondary power supply when the output voltage of each secondary power supply is a specified voltage, and the second timer counts a predetermined time. By the time, when the sub power supply normal signal is not output from at least one sub power supply monitoring circuit, the power on signal is deactivated. By monitoring the time, an abnormality can be detected for each power supply system of the load circuit, and the main power supply can be immediately turned off when there is an abnormality in any of the power supply systems.
According to the third aspect of the present invention, if the main power supply normal signal is not output from the main power supply monitoring circuit before the predetermined time is counted by the second timer, the power-on signal is deactivated. Therefore, by monitoring the time until the main power supply and sub power supply start-up completion from the start of the main power supply start-up, it can detect any abnormality in each power supply system of the main power supply, sub power supply and load circuit The main power can be turned off immediately if any of the problems occur. Since the start time of the main power supply starts, the rise time is not affected by the power-on state, and abnormality can be accurately detected for all power supply systems of the power supply device and the load circuit.

According to a fourth invention, the second timer includes a logic circuit element to which a voltage proportional to the voltage of the main power supply is input, and the logic circuit element of the second timer is used as a reference value for determining the start of the main power supply rise. Since the threshold is used, the power-on control circuit can be realized with a very simple circuit configuration.

According to a fifth aspect of the invention, the power supply device includes a power supply normal signal output indicating that the supplied DC power supply is a specified voltage, and the main power supply monitoring circuit is output from the power supply device. Since the power supply normal signal is used as the main power supply normal signal, the power-on control circuit can be realized with a minimum configuration when an ATX power supply or the like is used as the power supply device.

In the following drawings, like reference numerals designate like components or parts throughout the several views of the drawings.
It is a block diagram showing the example of the system which consists of a power supply device and the load circuit which receives supply of DC power supply (main power supply) from the power supply device. It is a block diagram showing the structural example of a power-on control circuit. It is a block diagram showing the example of a structure of the power-on control circuit in case a sub-power supply is provided. FIG. 10 is a block diagram illustrating another configuration example of a power-on control circuit when a sub power supply is provided. It is a circuit diagram showing the example which detects whether the voltage of the main power supply exceeded the predetermined value by a logic circuit element. FIG. 6 is a circuit diagram for generating a main power supply normal (or sub power supply normal) signal. 7 is a timing chart of the circuit shown in FIG. It is a timing chart showing operation of a power-on control circuit. It is a timing chart showing another operation | movement of a power-on control circuit. It is a timing chart showing operation | movement of the power-on control circuit in case a sub-power supply is provided. It is a flowchart which shows the example of the power-on control method. It is a flowchart which shows another example of the power-on control method. It is a flowchart which shows the example of the power-on control method in case a sub-power supply is provided. It is a figure showing the timing at the time of power activation prescribed | regulated with the ATX power supply.

(1) Configuration of power-on control circuit The power-on control circuit of the present invention is a system comprising a power supply device that outputs DC power in accordance with an input power-on signal and a load circuit that receives DC power from the power supply device. The power supply signal provided to the load circuit side and output to the power supply device is controlled.
The load circuit to which the power-on control circuit is applied is not particularly limited. For example, a mother circuit such as a personal computer, a peripheral circuit such as a CPU, a memory, an input / output, a video, or a peripheral device such as a hard disk drive. Etc.
The power supply device is not particularly limited as long as a signal (power-on signal) for controlling on / off of the output of the power supply is provided. A typical power supply device is an ATX power supply used in personal computers and the like.

A system including the power supply device and the load circuit is configured as shown in FIG. 1, for example. In the following drawings and description, a negative logic signal is represented by a sign #, but the logic of each signal is not limited.
The power supply device 2 receives supply of commercial power (AC) or the like, and supplies DC power (DCm) to the load circuit 9 in accordance with a power-on signal (PS_ON #) given from the outside. The power-on signal can be configured to be output from the load circuit 9 to the power supply device 2. This power-on signal may be any signal that can control on / off of the DC power supply to the power supply device 2. For example, the power-on signal PS_ON # is activated (on). During this period, the DC power source DCm is output to the load circuit 9, and a signal for controlling the DC power source not to be output to the load circuit 9 while the power-on signal is inactive (OFF) can be used.
Regardless of the number and type of DC power supplies DCm supplied from the power supply device 2, for example, one or more of the specified voltages of +12 V, +5 V, +3.3 V, and the like can be used.

The load circuit 9 is an electronic circuit that operates using a DC power source DCm output from the power supply device 2 as a main power source, and necessary power is supplied to each circuit unit and device 91 therein. The load circuit 9 can be provided with one or two or more sub-power supplies (92a, 92b, 92c, etc.) that receive the supply of the DC power supply DCm from the power supply device 2 and generate another DC power supply. The DC power DCm output from the power supply device 2 may be supplied to the internal circuit 91 or the like as it is, or the power generated by the sub power supply may be supplied.
In addition, the load circuit 9 is supplied with a standby power supply (VS) for a power supply control circuit while the DC power supply of the power supply device 2 is turned off.

  FIG. 2 shows a configuration example of the power-on control circuit provided in the load circuit 9. The power-on control circuit 1 includes an output circuit 3 that outputs a power-on signal 32 to the power supply device 2, a timer 5 that starts timing when the power-on signal is activated, and the voltage of the DC power source DCm is a substantially specified voltage. And a main power supply monitoring circuit 4 that outputs a main power supply normal signal PGm. The power-on control circuit 1 is configured so that the standby power VS is supplied even while the power supply device 2 is turned off.

  The output circuit 3 is a circuit that outputs a power-on signal 32 that instructs the power supply device 2 to turn on and off the DC power source DCm. The power-on signal 32 is connected to the PS_ON # terminal of the power supply device 2. For example, the power-on signal 32 is turned on while the supply of DC power DCm is requested, and the power-on signal 32 is stopped while the supply of DC power DCm is stopped. Can be configured to be off. The output circuit 3 is supplied with a power request signal 31 (PSon #) for requesting power-on on the load circuit side. Configure the power supply request signal 31 to be set to on when power on is requested due to factors such as power switch, software on / off (soft on / off), LAN activation (Wake on LAN), etc. Can do. When the power request signal 31 is on, the output circuit 3 turns on the power-on signal 32 for the power device 2.

  The main power supply monitoring circuit 4 is a circuit that generates a main power supply normal signal (PGm) by monitoring the voltage of the DC power supply DCm. The main power supply monitoring circuit 4 can be configured to turn on the main power supply normal signal PGm when the voltage of the DC power supply DCm is equal to or higher than Vmh with reference to a predetermined substantially prescribed voltage (Vmh). That is, the main power supply normal signal PGm is a signal indicating that the DC power supply DCm is normally output. Therefore, the substantially specified voltage Vmh serving as a reference can be set to the lowest level of the voltage range specified for each DC power source DCm. For example, when the output voltage of the DC power supply DCm is defined as (+ 12V ± 5%), the substantially specified voltage Vmh can be 95% of + 12V. However, since the power-on control circuit is intended for protection and safety in the event of an abnormality in the power supply system circuit, the substantially specified voltage Vmh may be set to a lower value (for example, 90% of the specified voltage). When there are a plurality of DC power supplies DCm, the main power supply monitoring circuit 4 can be provided for each DC power supply.

  When the power supply device 2 is an ATX power supply, a power supply normal signal (PWR_OK) indicating that the voltage of the DC power supply to be supplied is 95% or more of the specified voltage is provided. In such a case, it is not necessary to provide a circuit for generating the main power supply normal signal PGm as the main power supply monitoring circuit 4 in comparison with the reference voltage, and the power supply normal signal PWR_OK output from the ATX power supply is used as it is. It can be configured to be used as the signal PGm.

The timer 5 is a timer circuit for measuring a predetermined time (Ta), and is connected to the output circuit 3 and the main power supply monitoring circuit 4. The specific circuit configuration and timing method are not particularly limited. For example, a timer using a charging characteristic of capacitance or the like may be used, or a digital counter or the like may be used.
The timer 5 starts timing when the power supply device 2 is instructed to turn on the power, that is, when the power-on signal 32 output from the output circuit 3 changes to ON, and the main power monitoring circuit 4 sends the main power normal signal PGm. It can be configured to stop timing when is output. As a result, it is possible to monitor whether or not the DC power source DCm has become substantially the specified voltage Vmh within a predetermined time Ta after instructing the power source device 2 to turn on the power. The timer 5 can be configured to set the output signal TOa to ON when the main power normal signal PGm does not arrive within the predetermined time Ta. Then, by sending the output signal TOa of the timer 5 to the output circuit 3, it can be used as the power supply stop signal 7 for causing the power supply device 2 to stop the supply of DC power.

The power-on control circuit 1 can include a second timer 6 that starts timing when the voltage of the DC power source DCm exceeds a predetermined reference voltage (Vml).
As shown in FIG. 2, the second timer 6 includes a comparison circuit 61 that compares the voltage of the DC power supply DCm with the reference voltage Vml. The comparison circuit 61 can be configured to output a main power supply output start signal (PU) when the voltage of the DC power supply DCm exceeds the reference voltage Vml using a comparator having hysteresis characteristics. Thus, the second timer 6 can be configured to start timing by the main power supply output start signal PU and to stop timing when the main power supply normal signal PGm is output from the main power supply monitoring circuit 4.

  The reference voltage Vml can be a constant voltage at the start of rising of the DC power supply DCm, for example, 10% of a specified voltage of the DC power supply DCm. However, since this power-on control circuit is intended for protection and safety in the event of an abnormality in the power supply system circuit, the start of the main power supply may be determined based on the reference voltage, and the reference voltage Vml is set to a higher value. (For example, it may be 10 to 50% of the specified voltage, preferably 10 to 35%). When there are a plurality of DC power supplies DCm, the second timer 6 can be provided for each DC power supply.

As described above, since the value of the reference voltage Vml does not need to be exact, the comparison circuit 61 can be configured by a general-purpose logic circuit element. Specifically, as shown in FIG. 5, a voltage proportional to the voltage of the DC power supply DCm supplied from the power supply device 2 is input to the logic circuit element 611, and the main power supply output starts from the output signal of the logic circuit element 611. A signal PU can be generated. In this case, a voltage proportional to the voltage of the DC power supply DCm is compared by the threshold value of the logic circuit element 611.
For example, when the specified voltage of the DC power source DCm is +5 V, when the DC power source DCm is directly connected to the input terminal of the logic circuit element 611, the voltage exceeds the threshold value (Vth) of the logic circuit element 611. The main power output start signal PU can be turned on. If the threshold value Vth of the logic circuit element 611 is 1.6V, the main power supply output start signal PU is output when the DC power supply DCm exceeds 32% of the specified voltage 5V, which can be preferably used.

As shown in FIG. 2, the second timer 6 starts timing when the main power output start signal PU is output from the comparison circuit 61, and outputs an output signal (Tb) when a predetermined time (Tb) elapses. TOb) can be generated. A specific timing method and circuit configuration are not particularly limited. For example, a timer using a charging characteristic of capacitance or the like may be used, or a digital counter or the like may be used. The main power monitoring circuit 4 can be configured to stop timing when the main power normal signal PGm is output. As a result, it is possible to monitor whether or not the DC power source DCm supplied from the power source device 2 has risen beyond the reference voltage Vml and has reached the substantially specified voltage Vmh within a predetermined time Tb. The time Tb can be appropriately determined according to the characteristics of the power supply device and the load circuit.
The second timer 6 can be configured to turn on the output signal TOb when the main power normal signal PGm does not arrive within the predetermined time Tb. Then, by sending the output signal TOb of the second timer 6 to the output circuit 3, it can be used as a power supply stop signal 7 for causing the power supply device 2 to stop the supply of DC power.

This power-on control circuit can also be applied when the load circuit 9 is provided with one or two or more sub-power sources 92 that receive a DC power source DCm from the power source device 2 and generate another DC power source. it can.
FIG. 3 shows a configuration example in the case where one sub power supply 92 is mounted on the load circuit 9. As long as the sub power source 92 is supplied with the DC power source DCm from the power source device 2 and generates another DC power source (DCs), the conversion method and the generated voltage are not limited.
The power-on control circuit 11 includes a sub-power supply monitoring circuit 8 that monitors the voltage of the DC power supply output from the sub-power supply 92. The sub-power supply monitor circuit 8 has the voltage of the DC power supply DCs at a substantially specified voltage (Vsh). The sub power supply normal signal (PGs) is output when the power is on. The sub power supply normal signal PGs is input to the second timer (6c). The power-on control circuit 11 is configured in the same manner as the power-on control circuit 1 except that a sub-power normal signal PGs is input to the second timer 6c instead of the main power normal signal PGm.
When there are two or more sub-power supplies, a sub-power supply monitoring circuit that outputs a sub-power supply normal signal can be provided for each sub-power supply when the output DC voltage is substantially the specified voltage of the sub-power supply.

  The sub-power supply monitoring circuit 8 outputs a sub-power supply normal signal PGs that is on while the DC power supply DCs is equal to or higher than the substantially prescribed voltage Vsh of the sub-power supply 92. The substantially specified voltage Vsh can be set to the lowest level of the voltage range specified for the DC power supply DCs. For example, when the voltage of the DC power supply DCs is defined as (+ 5V ± 5%), the substantially specified voltage Vsh can be 95% of + 5V. However, as in the case of the substantially specified voltage Vmh for the main power supply, the substantially specified voltage Vsh for the sub power supply may be set to a lower value (for example, 90% of the specified voltage).

  Where in the circuit on the load circuit 9 the sub power supply monitoring circuit 8 is provided is not particularly limited. For example, the sub power supply monitoring circuit 8 may be built in the sub power supply 92 or may be provided in an initialization circuit or the like on the load circuit. That is, when a signal indicating that the voltage of the sub power supply is substantially the specified voltage (Vsh) is output from the control IC for the sub power supply, the signal is used as the sub power supply normal signal PGs. Can be used. In general, the load circuit is provided with an initialization circuit for giving a reset signal to the microprocessor or the like until the power supply voltage reaches a specified value. Therefore, the reset signal generated by the initialization circuit can be used as the sub power supply normal signal PGs.

The second timer 6c includes the comparison circuit 61. The second timer 6c starts measuring time by the main power output start signal PU output from the comparison circuit 61, and outputs an output signal (TOc) when a predetermined time (Tc) has elapsed. Is configured to occur. That is, the same configuration as that of the second timer 6 can be adopted.
The second timer 6c starts timing when the voltage of the DC power supply DCm rises above the reference voltage Vml, that is, when the main power supply output start signal PU output from the comparison circuit 61 is turned on. When the sub power supply normal signal PGs is output from the monitoring circuit 8, the time measurement can be stopped. As a result, it is possible to monitor whether or not the output voltage of the sub power supply 92 has become substantially the specified voltage Vsh within a predetermined time Tc after the DC power supply DCm supplied from the power supply device 2 exceeds the voltage Vml. The time Tc can be appropriately determined depending on the characteristics of the power supply device and the sub power supply, the load size of the load circuit, and the like.
If the output voltage of the sub power supply 92 does not become substantially the specified voltage Vsh within the predetermined time Tc, the second timer 6c sets the output signal TOc to ON. The output signal TOc is connected to the output circuit 3 and can be used as a power supply stop signal 7 for causing the power supply device 2 to stop supplying DC power.

  When there are two or more sub power sources, each sub power source is provided with a sub power source monitoring circuit 8, and at least one sub power source monitoring circuit 8 is connected to the sub power source monitoring circuit 8 until a predetermined time Tc is measured by one second timer 6c. When the power supply normal signal is not output, the output signal TOc of the second timer 6c can be set to ON. Further, the sub power supply monitoring circuit 8 and the second timer 6c may be provided for each sub power supply, the time Tc may be determined for each second timer 6c, and the output signal TOc may be output separately.

When the load circuit 9 is provided with one or two or more sub-power sources 92 that receive a DC power supply from the power supply 2 and generate another DC power source, the sub-power monitoring circuit 8 similar to the above is provided. And when the main power supply normal signal PGm is not output from the main power supply monitor circuit 4 until the predetermined time (Td) is measured by the second timer, or when at least one sub power supply monitor circuit 8 is normal When the signal PGs is not output, the power supply device 2 can be configured to stop the supply of DC power.
For example, in the power-on control circuit 12 shown in FIG. 4, the main power normal signal PGm output when the DC power DCm supplied from the power supply device 2 is approximately equal to or higher than the specified voltage Vmh, and the sub power monitoring circuit 8 A logical product (wired OR) signal with the sub power supply normal signal PGs to be output is connected to the second timer 6d. The second timer 6d can stop timing when both the main power normal signal PGm and the sub power normal signal PGs are turned on. Thus, it is monitored whether or not the DC power supply DCm becomes substantially the specified voltage Vmh and the output voltage DCs of the sub power supply becomes the substantially specified voltage Vsh within the time Td after the DC power supply DCm rises above the reference voltage Vml. can do. The time Td can be appropriately determined according to the characteristics of the power supply device and the sub power supply, the load size of the load circuit, and the like.
If either the main power normal signal PGm or the sub power normal signal PGs is not output within the time Td, the second timer 6d sets the output signal TOd on. The output signal TOd is connected to the output circuit 3 and can be used as a power supply stop signal 7 for causing the power supply device 2 to stop supplying DC power.

In the power-on control circuit 12, a logical product signal of the main power normal signal PGm and the sub power normal signal PGs is also connected to the timer 5a. The timer 5a can stop timing when both the main power supply normal signal PGm and the sub power supply normal signal PGs are turned on. Thus, it is monitored whether or not the DC power source DCm becomes the substantially specified voltage Vmh and the output DCs of the sub power source becomes the substantially specified voltage Vsh within a predetermined time Ta after the power supply device 2 is instructed to turn on the power. Can do.
If either the main power normal signal PGm or the sub power normal signal PGs is not output within the time Ta, the timer 5a sets the output signal TOa on. The output signal TOa is connected to the output circuit 3 and can be used as a power supply stop signal 7 for causing the power supply device 2 to stop supplying DC power.

When there are two or more sub power sources, the power-on control circuit 12 includes a sub power source monitoring circuit 8 for each sub power source, and the logical product (wired OR) of the sub power source normal signals PGs from the sub power source monitoring circuits 8. The timer can be configured to stop timing by each signal.
In addition to the above, various modifications and combinations of the main power supply monitoring circuit, the sub power supply monitoring circuit, each timer, and the timing start signal and stop signal of each timer are possible.

  The power supply device 2 illustrated in FIG. 4 outputs a power supply normal signal PG indicating that the DC power supply DCm to be output has a substantially specified voltage. If the power supply 2 is an ATX power supply, the PWR_OK signal corresponds to this. In such a case, it is not necessary to generate the main power supply normal signal PGm by the main power supply monitoring circuit 4, and the power supply normal signal PG of the power supply device 2 is used as the main power supply normal signal PGm as the main power supply monitoring circuit 4. Can be configured.

The main power supply monitoring circuit 4 and the sub power supply monitoring circuit 8 described above can be configured by a known voltage monitoring circuit as shown in FIG. 6, for example. The main voltage monitoring circuit 4 compares the voltage proportional to the voltage of the DC power supply DCm with the reference voltage 411 by the comparison circuit 41 having hysteresis characteristics, and outputs when the voltage of the DC power supply DCm is approximately equal to or higher than the specified voltage Vmh. The circuit 44 is turned on and the main power supply normal signal PGm is output. A delay circuit 43 that delays the main power normal signal PGm by time D may be provided. The output circuit 44 can be an open drain output. The operation of this circuit is as shown in the time chart of FIG. The same applies to the sub power supply monitoring circuit 8.
As described above, the main power supply normal signal PGm and the sub power supply normal signal PGs may be generated by a power supply itself having the same function as described above, a power supply control IC, an initialization circuit, or the like.

(2) Operation of the power-on control circuit FIG. 8 shows the operation of the power-on control circuit 1. The figure shows a commercial power supply VAC supplied to the power supply device 2, a power request signal Pson # input to the power-on control circuit 1 from the load circuit 9 side, and output from the output circuit 3 of the power-on control circuit 1 to the power supply device 2. Power supply signal PS_ON #, DC power supply DCm output from power supply device 2, main power supply normal signal PGm output from main power supply monitoring circuit 4, and output signal TO # of timer 5 are shown.

  Even when the commercial power supply VAC is supplied, the power supply device 2 does not output the DC power supply DCm to the load circuit 9 while the power-on signal PS_ON # is off (H). The power-on control circuit 1 is supplied with standby power (VS) and can monitor the state of the power request signal PSon #. On the load circuit 9 side, when a power-on is requested due to a power switch, software-on, LAN activation (Wake on LAN), etc., the power request signal PSon # is set to on (L), and power-on control is performed. The circuit 1 instructs the power supply device 2 to turn on the power by turning on the power-on signal PS_ON # (S1). At this time, the power-on control circuit 1 starts a timer at time Ta. When the power-on signal PS_ON # is turned on, the power supply device 2 starts up the DC power supply DCm.

  When there is no abnormality in the load circuit 9 and the power supply device 2, the DC power supply DCm rises to a specified voltage (DCmn) as shown by a broken line. In this case, when the direct-current power source DCm exceeds approximately the specified voltage Vmh, the main power source monitoring circuit 4 outputs the main power source normal signal PGm (PGmn), thereby stopping the time measurement, so that the output signal TO # of the timer 5 is Stays off. Therefore, the power-on signal PS_ON # remains on, and the DC power source DCm is continuously supplied from the power supply device 2.

  On the other hand, when there is an abnormality in the load circuit 9 or the power supply device 2, the DC power supply DCm does not rise to the specified voltage (DCma) as shown by the solid line. Then, the main power supply normal circuit PGm is not output from the main power supply monitoring circuit 4, and when the time Ta elapses, the output signal TO # of the timer 5 is turned on (L). As a result, the power-on signal PS_ON # is turned off (H), and the power supply device 2 turns off (off) the output of the DC power supply DCm.

The time T1 from when the power-on signal PS_ON # is turned on until the DC power source DCm exceeds the substantially specified voltage Vmh differs depending on the capacity / characteristics of the power supply device 2, the load size of the load circuit 9, and the like. Also, it varies greatly depending on the state of the power supply circuit when the power is turned on. For example, when the elapsed time since the power is turned off is short, the time T1 is short because the electrostatic capacity is not sufficiently discharged. The time T3 from when the direct current power source DCm exceeds substantially the specified voltage Vmh to when the main power source normal signal PGm is output is determined by the delay time of the main power source monitoring circuit 4.
For the purpose of this power-on control circuit, the timer time Ta is preferably longer than the time (T1 + T3) that is maximum under various conditions under normal conditions and as short as possible.

FIG. 9 shows the operation of the power-on control circuit 1 including the second timer 6. Each signal in the figure is the same as that in FIG. 8, and a description of common operations will be omitted.
As described above, the power supply device 2 starts up the DC power supply DCm when the power-on signal PS_ON # is turned on. After the power-on signal PS_ON # is turned on, when the voltage of the DC power source DCm exceeds the reference voltage Vml (S2), the second timer 6 at time Tb is started.

When there is no abnormality in the load circuit 9 and the power supply device 2, the main power supply normal signal PGm is output from the main power supply monitoring circuit 4 (PGmn) when the DC power supply DCm exceeds the substantially specified voltage Vmh, as described above. As a result, the timing is stopped, so that the output signal TO # of the second timer 6 is off and the power-on signal PS_ON # is continuously on, and the DC power source DCm is continuously output from the power supply device 2.
On the other hand, when the load circuit 9 or the power supply device 2 is abnormal and the DC power supply DCm does not rise to the specified voltage Vmh (DCma), the output signal TO # of the second timer 6 is turned on when the time Tb elapses as described above. (L). As a result, the power-on signal PS_ON # is turned off (H), and the power supply device 2 turns off (off) the output of the DC power supply DCm.

The time (T1-T2) from when the power-on signal PS_ON # is turned on until the DC power source DCm starts to rise varies greatly depending on the state of the power circuit when the power is turned on. For example, when the elapsed time since the power was turned off before is short, the time (T1-T2) is shortened because the electrostatic capacity is not sufficiently discharged. For this reason, in order to increase the accuracy of abnormality detection, the time until the DC power source starts to rise (S2) until the DC power source DCm starts to rise until it rises to approximately the specified voltage Vmh is excluded. It is preferable to monitor this time, that is, (T2 + T3). Since this time is monitored by the second timer, it is possible to improve the accuracy of abnormality detection.
The time T2 from when the DC power source DCm exceeds the reference voltage Vml until it substantially exceeds the specified voltage Vmh varies depending on the characteristics of the power supply device 2 and the load circuit 9. Therefore, the time Tb of the second timer is preferably longer than the time (T2 + T3) that is maximum under various conditions under normal conditions and as short as possible (for example, 500 ms to 1 s).

FIG. 10 shows the operation of the power-on control circuit 11 including the sub power supply monitoring circuit 8. In the figure, DCs represents a DC power source output from the sub power source 92, PGs represents a sub power source normal signal output from the sub power source monitoring circuit 8, and other signals are the same as those in FIG. Description is omitted.
Similarly to the above, when the voltage of the DC power supply DCm exceeds the reference voltage Vml (S2), the power-on control circuit 11 starts the second timer 6c at time Tc.

When there is no abnormality in the load circuit 9, the sub power source 8, and the power source device 2, the DC power source DCs is started by the sub power source upon receiving the supply of the DC power source DCm (DC sn). When the voltage of the DC power supply DCs exceeds the substantially specified voltage Vsh, the sub power supply normal signal PGs is output from the sub power supply monitoring circuit 8 (PGsn). As a result, the timing is stopped, so that the output signal TO # of the second timer 6c is off and the power-on signal PS_ON # is continuously on, and the DC power supply DCm is continuously supplied from the power supply device 2.
On the other hand, there is an abnormality in the load circuit 9, the sub power supply 8, or the power supply device 2, and the sub power supply DCs rises to the specified voltage regardless of whether the DC power supply DCm rises to the specified voltage (DCmn or DCma). If not (DCsa), the sub power supply normal signal PGs is not output. When the time Tc elapses, the output signal TO # of the second timer 6c is turned on (L), so that the power-on signal PS_ON # is turned off (H), and the power supply device 2 cuts off the output of the DC power supply DCm (off). ).

  The time from when the DC power source DCm exceeds the reference voltage Vml to when the output of the sub power source 92 exceeds approximately the specified voltage Vsh varies depending on the characteristics of the power supply device 2, the sub power source 92, and the load circuit 9. Further, a delay time D occurs from when the output of the sub power supply substantially exceeds the specified voltage Vsh until the sub power supply normal signal PGsn is output. Therefore, in this power-on control circuit, the time Tc of the second timer 6c is set to the maximum time from when the DC power supply DCm exceeds the voltage Vml until the sub power supply normal signal PGsn is output under various conditions under normal conditions. It is preferable that the time is longer and as short as possible (for example, 600 ms to 1 s).

  FIG. 14 shows the timing at the start of power supply defined for the ATX power supply (see ATX12V Power Supply Design Guide Version 2.2). In the ATX power supply, the power-on time T1 (T1 <500 ms) from when the power-on signal PS_ON # is turned on until the output voltage (+ 12V, + 5V, + 3.3V) reaches 95% of the specified voltage, the output voltage is Rise time T2 (0.1 ms ≦ T2 ≦ 20 ms) until it reaches 95% after 10% or more of the specified voltage, and thereafter, until the power supply normal signal PWR_OK indicating that each output voltage is normal is output Delay time T3 and rise time T4 (100 ms <T3 <500 ms, T4 ≦ 10 ms) are respectively defined. Therefore, the time (T1 + T3 + T4) from when the power-on signal PS_ON # is turned on to when the power normal signal PWR_OK is turned on is about 1 second at the longest. Further, the time (T2 + T3 + T4) from when the output voltage becomes 10% or more to when the power supply normal signal PWR_OK is turned on is about 0.5 seconds at the longest.

When the power supply 2 is an ATX power supply, considering the above, the time Ta monitored by the timer is preferably about 1 second. As described above, the time T1 from when the power-on signal PS_ON # is turned on until the output voltage rises depends on the characteristics of the power supply device and the load circuit. In particular, the time until the output voltage starts to rise (T1-T2) is the discharge of the power supply. It varies greatly depending on the condition. For this reason, in order to detect whether or not there is an abnormality on the load circuit side, it is possible to detect more accurately by monitoring by the time (T2 + T3 + T4) from when the output voltage starts to rise until the power supply becomes normal. Therefore, the time Tb monitored by the second timer is preferably about 0.5 seconds.
If a sub power supply is provided, the time from when the main power source starts up until the sub power source starts up depends on the characteristics of the sub power source and the load, but until the sub power source normal signal is output after the sub power source starts up. This delay time can usually be set appropriately. Considering these points, the time Tc monitored by the second timer is preferably in the range of about 0.6 to 1 second.

(3) Power-on control method Various power-on control methods are possible using the power-on control circuit exemplified above. The power-on control method is used in the load circuit 9 that is connected to the power supply device 2 that supplies DC power in accordance with an input power-on signal and receives the supply of DC power as a main power supply.
First, when a power-on signal is activated for the power supply device 2, a power-on step that starts timing by a timer, and the voltage of the DC power supply (main power supply) output from the power supply device 2 becomes a substantially specified voltage. When the main power supply monitoring step determines that the main power supply is normal, and the main power supply monitoring step determines that the main power supply is normal before the predetermined time is counted by the timer, the power-on signal is deactivated. By doing so, it is possible to provide a power-on control method 1 including a power supply stop step for stopping the supply of DC power to the power supply device.

The control flow of the power-on control method 1 is shown in FIG. During standby, power-on factors such as power switch, software-on, LAN activation, etc. are monitored (S01), and if any of them occurs, the power-on signal (PS_ON #) is turned on to turn on the power The apparatus 2 is instructed to turn on the power (S10). At this time, a timer (first timer) for a predetermined time Ta is started to start timing (S11). Thereafter, it is monitored whether or not the voltage of the DC power supply (main power supply) output from the power supply device 2 has become approximately the specified voltage Vmh (S61). Then, when the voltage of the main power source becomes substantially the specified voltage within the time Ta, it is determined that the main power source is normal, the timer is stopped (S71), and the control process is terminated. On the other hand, if the main power supply does not become normal before the time Ta elapses, the power-on signal is turned off (S21, S81). As a result, the supply of DC power to the power supply device 2 can be stopped.
The power-on step comprises steps S10 and S11, the main power monitoring step comprises step S61, and the power stop step comprises steps S21 and S81.

  Second, in the power-on control method 1, a main power output start detection step for starting timing by a second timer when the voltage of the main power exceeds a predetermined value, and a predetermined time is counted by the second timer. A second power supply stopping step for stopping the supply of DC power to the power supply device by inactivating a power-on signal if the main power supply monitoring step does not determine that the main power supply is normal by the main power monitoring step, The power-on control method 2 can further be provided.

In the flowchart of FIG. 12, steps S01, S10, S11, S61 and the like are the same as in the previous figure. After the first timer is started in step S11, it is monitored whether or not the voltage of the main power source exceeds a predetermined value (reference voltage Vml) (S31), and when the reference voltage Vml is exceeded, the predetermined time Tb is counted. The second timer is started (S32). Thereafter, it is monitored whether or not the main power supply is normal (S61). When the main power supply is normal within the time Ta and within the time Tb, the first and second timers are stopped (S72), and the control process is terminated. On the other hand, if the main power supply does not become normal before the time Ta or Tb elapses, the power-on signal is turned off (S81). As a result, the supply of DC power to the power supply device 2 can be stopped.
The main power output start detection step comprises steps S31 and S32, and the second power supply stop step comprises steps S51 and S81.

  Third, in the power-on control method 1, the load circuit 9 is provided with one or more sub-power sources 92 that receive the supply of the main power and output another DC power source. A main power supply output start detection step for starting timing by a second timer when the voltage exceeds a predetermined value; and a sub power supply for determining that the sub power supply is normal for the sub power supply when the output voltage of each of the sub power supplies becomes substantially a specified voltage. If at least one of the sub-power supplies is not determined to be normal by the sub-power supply monitoring step before the predetermined time is counted by the second timer, the power-on signal is turned off. The power-on control method 3 can further include a second power supply stop step of stopping the supply of the direct-current power to the power supply device when activated.

In the flowchart of FIG. 13, the steps up to the main power output start detection step (S31, S32) are the same as those in the power-on control method 2. Thereafter, it is monitored whether or not the output voltage of each sub-power supply has become a substantially specified voltage Vsh. If it is determined that the sub power supply is normal for all the sub power supplies within the predetermined time Tb, the first and second timers are stopped (S62, S72), and the control process is terminated. On the other hand, if the secondary power supply does not become normal for any of the secondary power supplies before the time Ta or Tb elapses, the power-on signal is turned off (S81). As a result, the supply of DC power to the power supply device 2 can be stopped.
The sub power supply monitoring step includes step S62, and the second power supply stop step includes steps S51 and S81.

  Fourth, in the power-on control method 3, the second power stop step monitors whether or not the main power has become normal before the second timer counts the predetermined time Tb (FIG. 13). S62), if it is not determined that the main power supply is normal, the power-on control method 4 can be used to stop the supply of the DC power to the power supply device by deactivating the power-on signal.

  Fifth, in any one of the power-on control methods 2 to 4, in the main power output start detection step, as the predetermined value, a threshold value of a logic circuit element to which a voltage proportional to the voltage of the main power is input is set. The power-on control method 5 can be used.

  Sixth, in any one of the power-on control methods 1 to 5, the power supply device 2 includes an output of a power supply normal signal indicating that the DC power supply to be supplied has a substantially specified voltage, The main power supply monitoring step may be a power-on control method 6 for determining that the main power supply is normal when the power supply normal signal is input from the power supply device.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention depending on the purpose and application.

  DESCRIPTION OF SYMBOLS 1, 11, 12; Power-on control circuit, 2; Power supply device, 3; Output circuit, 31; Power supply request signal (PSon #), 32; Power-on signal (PS_ON #), 4; 5a; timer (first timer), 6, 6c, 6d; second timer, 61; voltage comparison circuit, 7; power supply stop signal, 8; auxiliary power supply monitoring circuit, 9; load circuit, 92, 92a, 92b, 92c Sub power source, DCm; DC power source (main power source) output from the power supply unit, DCs; DC power source output from the sub power source, PGm; main power source normal signal, PGs; sub power source normal signal, PU; main power source output start Signal, TOa, TOb, TOc, TOd, TO #; Timer output signal, VAC; Commercial power supply, VS; Standby power supply.

Claims (5)

A power-on control circuit that is connected to a power supply device that supplies DC power in accordance with an input power-on signal and is provided in a load circuit that receives supply of the DC power as main power,
An output circuit for outputting the power-on signal to the power supply device;
A timer that starts timing when the power-on signal is activated;
A main power supply monitoring circuit that outputs a main power supply normal signal when the voltage of the main power supply is a specified voltage;
With
If the main power supply normal signal is not output from the main power supply monitoring circuit until the predetermined time is counted by the timer, the power supply signal is deactivated to inactivate the DC power supply. Stop the supply ,
A second timer for starting timing when the voltage of the main power source exceeds a predetermined value;
If the main power supply normal signal is not output from the main power supply monitoring circuit before the predetermined time is counted by the second timer, the power supply device is inactivated by deactivating the power-on signal. power-on control circuit, characterized in Rukoto stops the supply of the DC power supply. A power-on control circuit that is connected to a power supply device that supplies DC power in accordance with an input power-on signal and is provided in a load circuit that receives supply of the DC power as main power,
An output circuit for outputting the power-on signal to the power supply device;
A timer that starts timing when the power-on signal is activated;
A main power supply monitoring circuit that outputs a main power supply normal signal when the voltage of the main power supply is a specified voltage;
With
If the main power supply normal signal is not output from the main power supply monitoring circuit until the predetermined time is counted by the timer, the power supply signal is deactivated to inactivate the DC power supply. Stop the supply ,
The load circuit is provided with one or more sub-power supplies that receive the supply of the main power and output another DC power supply,
A second timer that starts timing when the voltage of the main power source exceeds a predetermined value;
A sub power supply monitoring circuit that outputs a sub power supply normal signal for the sub power supply when the output voltage of each sub power supply is a specified voltage;
Further comprising
If the sub power supply normal signal is not output from at least one of the sub power supply monitoring circuits before the predetermined time is counted by the second timer, the power supply signal is deactivated to deactivate the power supply A power-on control circuit that stops the supply of the DC power to the apparatus . If the main power supply normal signal is not output from the main power supply monitoring circuit before the predetermined time is counted by the second timer, the power supply device is deactivated to deactivate the power supply signal. The power-on control circuit according to claim 2, wherein the supply of the DC power is stopped. The second timer includes a logic circuit element voltage proportional to the voltage of the main power supply is input, the power-on control according to any one of claims 1 to 3 using a threshold of the logic circuit elements as the predetermined value circuit. The power supply device includes an output of a power supply normal signal indicating that the DC power supply to be supplied is a specified voltage,
The main power supply monitoring circuit, power-on control circuit according to any one of claims 1 to 4 using the power good signal output from the power supply device as the main power source normal signal.

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