JPH04105525A - Power feeding system - Google Patents

Abstract

PURPOSE:To reduce mounting space of a component and to reduce in size a device by composing to connect a power source and a backup circuit parallel to a load in the device having a storage function. CONSTITUTION:A level detector 10 of a backup circuit 6 produces an output when it exceeds a preset threshold voltage Vth to drive an N-P-N transistor 9. Thus, the transistor 9 drives a relay 7, and the circuit 6 is connected to a load 5. On the other hand, after the operation of the circuit 6 is completed, even if abnormal stop of a power source 1 occurs, the circuit 6 is already operated, power necessary to back up the system is supplied by the circuit 6. Accordingly, the backup time of the system can be sufficiently obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply circuit for a device having a memory function, and more particularly to a power supply system that ensures sufficient backup time for the system when the power supply of the device is abnormally stopped.

[Conventional technology]

Conventionally, a device having this type of storage function uses a dedicated battery to ensure system backup time when the power supply of the device is abnormally stopped. An example of this method will be explained with reference to FIG. 4.

FIG. 4 shows the power supply system of this conventional device having a memory function. Lejl load 5 with memory function
, and a battery 15.

Here, when the power supply 1 is operating normally, the power necessary for the load 5 side is supplied from the power supply 1. When the power supply 1 abnormally stops, the system is backed up, and the necessary power is supplied from the battery 15 at that time. Also, if the power required for bank up is larger than the load side configuration,
This can be addressed by using a battery with a large power supply capacity.

[Problem to be solved by the invention]

With the above-mentioned conventional technology, a dedicated battery is required in order to secure system bank amplifier time when the power supply of a device with a storage function is abnormally stopped, and a battery with a larger capacity is required to cope with an increase in the load configuration. I have to change the battery.

Further, the battery itself requires a large mounting space, and there is a problem that it lacks versatility when configuring the device.

In view of the above points, the present invention has been made in order to solve the conventional problems, and provides a power supply system that uses a backup circuit instead of a dedicated battery and allows for a reduction in mounting space. [Means for Solving the Problem] In order to achieve this purpose, the power supply method of the present invention connects the output positive terminal of the power supply to the positive terminal of the load via a diode connected in the forward direction. At the same time, the output positive terminal of the power supply is connected via a resistor to the other terminal of a relay contact whose one terminal is connected to the connection point between the cathode terminal of the diode and the positive terminal of the load, and these resistors and A bank up circuit is provided in which the positive terminal is connected to the connection point with the relay contact, and the negative terminal is connected to the connection point between the negative output terminal of the power supply and the negative terminal of the load. A capacitor with one terminal connected and the other terminal connected to the negative terminal is monitored and the voltage stored in the capacitor is output when the voltage exceeds a preset threshold voltage. It is composed of a level detecting section that outputs a level, and a relay driving section that operates based on the output of the level detecting section and controls opening and closing of the relay contacts.

[Effect]

According to the present invention, in a device having a memory function, sufficient system backup time can be secured when the power supply of the device stops abnormally, and system backup can be performed without using a battery (or by using a charging capacitor according to the load). I can do it.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the power feeding system according to the present invention, and FIG. 2 is a specific circuit configuration diagram thereof.

As shown in FIGS. 1 and 2, the power supply system of this embodiment has a configuration in which a power source 1 and a backup circuit 6 are connected in parallel to a load 5, and the power source 1 is connected to a DC/DC converter 2. and diode 3. The back amplifier circuit 6 is composed of a resistor 4, a relay 7, a diode 8. NPN) transistor9. It is composed of a level detection section 10 and a capacitor 11.

Here, the output positive terminal of the power supply l is the first terminal connected in the forward direction.
The anode terminal of the diode 3 and one terminal of the resistor 4 are connected in common, and the positive terminal of the load 5 and one terminal of the contact 7a of the relay are connected to the cathode terminal of the diode 3. The other terminal of the resistor 4 is the other terminal of the relay contact 7a and one terminal of the relay (coil part) 7.

Cathode terminal of second diode 8, level detection section 10
The positive terminal of the relay 7 and the positive terminal of the capacitor 11 are connected in common, and the other terminal of the relay 7, the anode terminal of the second diode 8, and the collector terminal of the NPN transistor 9 are connected in common. Also, the output terminal 10 of the level detection section 10. and the base terminal of NPN) transistor 9 are connected, and the output negative terminal of power supply 1 and the negative terminal of load 5, the eminter terminal of NPN) transistor 9,
The negative terminal of the level detection section 10 and the negative terminal of the capacitor 11 are respectively connected in common. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Next, FIG. 2 shows the operation of the power feeding system according to the above embodiment.

This will be explained using FIG. Here, when the power supply 1 is in operation, a voltage waveform as shown in FIG. 3(a) appears at point a shown in FIG. At this time, a voltage waveform as shown in FIG. 3(b), which is obtained by integrating the voltage waveform at point a, appears at point b shown in FIG. And the backup circuit 60 level detection section 10
monitors the potential at point b, and outputs an output to drive the NPN transistor 9 when it exceeds a preset threshold voltage th. For this reason, NP
N) The transistor 9 drives the relay 7, and the relay contact 7a
is closed at time point I shown in FIG. After the operation of the back amplifier circuit 6 is completed, the power supply 1
Even if an abnormal stop occurs, the backup circuit 6 is already activated.
is in operation, and the buffer knob circuit 6 supplies the power necessary for the system valve. Therefore, sufficient bank-up time for the system can be ensured.

By using the power supply method of this embodiment in a device having a memory function in this way, a battery becomes unnecessary. Also,
An increase in the load configuration can be handled by increasing the number of capacitors 11 or the capacitance, and compared to a power supply system using a battery, the mounting space for components is smaller and the device configuration is simpler.

〔Effect of the invention〕

As explained above, the power supply system of the present invention uses a configuration in which a power supply and a backup circuit are connected to the load in parallel in a device having a memory function, thereby reducing the bank amplifier time of a system equivalent to a conventional system in a smaller space than before. This has the effect of reducing the mounting space for components and downsizing the device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the power feeding system according to the present invention, FIG. 2 is a specific circuit configuration diagram thereof, and FIG.
FIG. 4 is a block diagram showing an example of a conventional power feeding system. 1...1B, 2...D C/DC converter, 3
...Diode, 4...Resistance, 5...Load, 6.
... Backup circuit, 7... Relay 7a... Relay contact, 8... Diode, 9... NPN transistor, 10... Level detector, 11... Capacitor. Patent applicant: NEC Corporation

Claims (1)

[Claims] The positive output terminal of the power supply is connected to the positive terminal of the load through a diode connected in the forward direction, and the positive output terminal of the power supply is connected through a resistor so that one terminal is connected to the cathode terminal of the diode and the positive terminal of the load. The positive terminal is connected to the other terminal of the relay contact connected to the connection point between these resistors and the relay contact, and the negative terminal is connected to the connection point between the negative output terminal of the power supply and the negative terminal of the load. A backup circuit is provided with terminals connected to each other, and this backup circuit monitors a capacitor with one terminal connected to its positive terminal and the other terminal connected to its negative terminal, and the voltage stored in the capacitor. and a level detection unit that outputs an output when the voltage exceeds a preset threshold voltage, and a relay drive unit that operates based on the output of the level detection unit to control opening and closing of the relay contacts. Characteristic power supply method.