JPH0698481A - Power supply device - Google Patents

Abstract

PURPOSE:To provide a power supply device wherein a power loss is reduced as far as possible and the generation of a momentary power failure state can be prevented. CONSTITUTION:A main power supply E1, an auxliary power supply E2 and fuses F11, F21 are connected to input terminals CN1, CN2, and protective diodes D11, D21, and diodes D12, D22 for reversecurrent prevention use are connected to the fuses. Normally closed contacts S111, S211, for relays R11, R21 are connected in parallel with the diodes D12, D22, and coils L131, L231, for individual reverse-current detection sensors S13, S23 are connected. A load R one end of which has been grounded is connected to the coils L131, L231, Hall elements P131, P231 are connected, and coils L111, L211, for the relays R11, R21, are connected to the individual elements P131, P231. Electric power is supplied to the load R via the parallel-connected relay contact whose power supply voltage is higher, and it is possible to prevent a momentary power failure even when the voltage on one side is lowered. An electric current is supplied via the relay contact. When a reverse current flows, the sensor detects it and opens the contact on the side on which the reverse current has been generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device, and more particularly to a power supply device used for battery application equipment in which momentary power failure is not allowed.

[0002]

2. Description of the Related Art Batteries are generally used as power supply devices for surveying points on the earth using satellites by GPS receivers and for continuous outdoor measurement of various weather conditions such as temperature, humidity and atmospheric pressure. ing. In this type of surveying or measurement, GPS receivers and measuring devices are operated for a considerably long time, and instantaneous power failure is not allowed in these devices. Therefore, in this type of surveying or measurement, it is common practice to prepare an auxiliary power supply in addition to the main power supply required for the operation of the devices.

However, even if a switch or the like is used in the means for switching the auxiliary power supply to the devices when the main power supply is consumed, a momentary power failure occurs when the main power supply is switched to the auxiliary power supply. As a means for avoiding such a momentary power failure state, for example, the power supply device shown in FIG. 2 can be considered. The power supply device shown in the figure has a pair of input terminals A and B to which main and auxiliary DC power supplies are connected and which are connected in parallel to a load R, and between the input terminals A and B and the load R, respectively. It is composed of a pair of reverse current prevention diodes D provided.

In the power supply device configured as described above, when the main and auxiliary DC power supplies are connected to the input terminals A and B, respectively, the diode D, whichever has the higher voltage of the main and auxiliary DC power supplies, is connected. Is turned on to supply electric power to the load R, so that even if one of the DC power supplies is consumed, a momentary power failure state does not occur when the power is switched. However, such a power supply device has the technical problems described below.

[0005]

That is, in the power supply device shown in FIG. 2, the forward current corresponding to the load R always flows through the diode D on the side supplying the load R with power. voltage drop due to the current (V _F = 1.0 to 1.6
v) has occurred. This voltage drop is not so much affected when the current consumption is small, but when the current consumption is about several amperes, it becomes considerably large and the diode D
Loss is a problem.

The present invention has been made in view of the above problems, and an object thereof is to reduce the power loss as much as possible and to prevent the occurrence of a momentary power failure state. To provide.

[0007]

In order to achieve the above object, the present invention provides a pair of input terminals to which main and auxiliary DC power supplies are connected and which are connected in parallel to a load, and the input terminals and the load. And a pair of normally-closed relay contacts respectively provided between, and a pair of backflow prevention diodes respectively connected in parallel to the normally-closed relay contacts, respectively between the input terminal and the load A pair of reverse current detection sensors that are provided to activate the relay on the side where the reverse current is generated when the reverse current from the load to the input terminal side is detected and to open the normally closed contact are provided. It is characterized by having.

[0008]

According to the power supply device having the above construction, the main DC power supply is connected to one of the input terminals connected in parallel with the load, and the auxiliary DC power supply is connected to the other input terminal. Since the power is supplied to the load from the higher one through the normally-closed type relay contact, it is possible to prevent a momentary power failure state even when the power supply voltage of either one of the power supplies drops. Since the current supplied at this time is performed through the normally-closed type relay contact, there is almost no power loss in this portion. When a reverse current flows from the one with the higher power supply voltage to the one with the lower power supply voltage, the reverse current detection sensor detects it and activates the relay on the side where the reverse current is generated, opening the normally closed contact. To do. The chattering of the contact at this time is absorbed by the backflow prevention diode connected in parallel with the contact, and the reverse current is prevented from flowing to the power supply side.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of a power supply device according to the present invention. The power supply device shown in the figure has a pair of input terminals CN _{1 and} CN ₂ , a pair of fuses F ₁₁ and F ₂₁ , a pair of protection diodes D ₁₁ and D _21, and a pair of backflow prevention diodes D ₁₂ and D. ₂₂ , a pair of relays R ₁₁ and R _21, and a pair of reverse current detection sensors S ₁₃ and S ₂₃ .

In this embodiment, the relays R ₁₁ and R ₂₁ are 1
Two normally closed contacts S _111, S ₂₁₁ and excitation coils L _111, L
Those having ₂₁₁ and ₂₁₁ are used. The reverse current detection sensors S ₁₃ and S ₂₃ are composed of Hall elements P ₁₃₁ and P _231, which are turned on and off depending on the direction in which a magnetic field is applied, and excitation coils L ₁₃₁ and L _{231 of} the Hall elements P ₁₃₁ and P _231. In this embodiment, the Hall elements P ₁₃₁ and P ₂₃₁ are
Excitation coils L ₁₃₁ and L so that they are turned on in a steady state
A magnetic field of ₂₃₁ is set.

[0011] The input terminal CN _1, CN _2, with each main and auxiliary DC power source E _1, E ₂ (specifically, a battery power supply) is connected to each input terminal CN _1, CN ₂ is , One ends of the fuses F ₁₁ and F ₂₁ are connected. The other ends of the fuses F ₁₁ and F ₂₁ are connected to the anodes of the protection diodes D ₁₁ and D ₂₁ whose cathodes are grounded, and to the cathodes of the backflow prevention diodes D ₁₂ and D ₂₂ .

Backflow prevention diode D₁₂, D_{twenty two}In each
Relay R₁₁, R_{twenty one}Normally closed contact S_{11 1,}S₂₁₁Respectively
It is connected in parallel. Also, a reverse current prevention diode
D₁₂, D _{twenty two}Each reverse current detection sensor on the anode side of
S₁₃, S_{twenty three}Excitation coil L₁₃₁, L ₂₃₁One end of is connected
Has been done. Excitation coil L₁₃₁, L₂₃₁At the other end of
A load R whose one end is grounded is connected and a reverse current
Detection sensor S₁₃, S_{twenty three}Hall element P₁₃₁, P₂₃₁One
The ends are commonly connected. Each Hall element P₁₃₁, P₂₃₁
The other end of the relay R has one end grounded₁₁, R_{twenty one}Encouragement of
Magnetic coil L_111,L₂₁₁Are connected.

In the power supply device configured as described above, the main and auxiliary DC power supplies E _1, E ₂ are the fuses F ₁₁ , F ₂₁ ,
The relays R ₁₁ and R ₂₁ are connected in parallel to the load R via the normally closed contacts S _{111 and} S ₂₁₁ , and the reverse current detection sensors S ₁₃ and S ₂₃ for excitation coils L ₁₃₁ and L ₂₃₁ . Now, where the main and the output voltage of the auxiliary power source E _1, E ₂ is V _1, V ₂ respectively, and, when a V _1> V _2, the load R is fuse from the main power supply E ₁ F ₁₁ , normally closed contact S
_A current is supplied by a circuit passing through _{111 and the} exciting coil L ₁₃₁ .

At this time, V ₂ is V ₁ on the auxiliary power source E ₂ side.
Therefore, a reverse current tends to flow from the load R side toward the power source E ₂ , but when a reverse current occurs, the direction of the magnetic field of the exciting coil L ₂₃₁ of the reverse current detection sensor S ₂₃ becomes a steady state. Conversely, the Hall element P ₂₃₁ is turned on. When the Hall element P ₂₃₁ is turned on, current flows through the exciting coil L ₂₁₁ of the relay R _21, relay R ₂₁ and actuated, its normally closed contacts S ₂₁₁ is opened, the auxiliary power source E ₂ is prevented backflow Since the diode D ₂₂ is connected to the load R through the diode D ₂₂ , a reverse current is blocked by the diode D _{22 and} prevented from flowing into the auxiliary power source E ₂ .

In this case, the backflow prevention diode D ₂₂ is
It also has a function of preventing chattering of the normally closed contact S ₂₁₁ . Then, for example, when the measurement by the GPS receiver progresses, the main power supply E ₁ is consumed, and the relationship of the output voltage with the auxiliary power supply E ₂ is reversed and V ₁ <V ₂ , then the auxiliary power supply E 1 _A current is supplied to the load R from the circuit ₂ through the fuse F ₂₁ , the normally closed contact S _{211, and the} exciting coil L ₂₃₁ and the reverse current causes the Hall element P ₁₃₁ to turn on, thereby preventing the reverse current. Reverse current is blocked by D ₁₂ , and the power supply is switched.

According to the power supply device having the above-described structure, the load R is connected to the main and auxiliary power supplies E _{1 and} E _{2 with} the higher power supply voltage via the normally closed relay contacts S _{111 and} S _211. Since electric power is being supplied to the device, even if one of the power supply voltages drops, it is possible to prevent a momentary power failure. Since the current supplied at this time is performed through the normally closed relay contacts S _111, S ₂₁₁ , almost no power loss occurs at this portion.

When a reverse current flows from a higher power supply voltage to a lower power supply voltage, the Hall elements P ₁₃₁ and P ₂₃₁ of the reverse current detection sensors S ₁₃ and S ₂₃ detect this and a reverse current is generated. The relays R ₁₁ and R ₂₁ on the operating side are operated to open the normally closed contacts S _{111 and} S ₂₁₁ . Contact points at this time S _111, S
The chattering of ₂₁₁ is absorbed by the backflow prevention diodes D ₁₁ and D ₂₁ connected in parallel to the contacts S _{111 and} S ₂₁₁ , and the reverse current is prevented from flowing to the power supply side.

The protection diodes D ₁₁ and D ₂₁ shown in the above embodiment are for protecting the load R when the polarities of the power sources E _{1 and} E ₂ are reversely connected.

[0019]

As described above in detail in the embodiments,
According to the power supply device of the present invention, with a simple configuration,
In addition to avoiding a momentary power failure, the power loss can be greatly reduced and the service life of the power battery can be extended.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an example of a power supply device according to the present invention.

FIG. 2 is a circuit diagram showing a conventional power supply device.

[Explanation of symbols]

 E₁ Main DC power supply E₂ Auxiliary DC power supply  R load CN_1,CN₂ Input terminal F₁₁, F_{twenty one} Hughes D₁₁, D_{twenty one} Protection diode D₁₂, D_{twenty two} Backflow prevention diode R₁₁, R_{twenty one} Relay S₁₃, S_{twenty three} Reverse current detection sensor S_111,S₂₁₁ Normally closed contact L_111,L₂₁₁ Excitation coil P₁₃₁, P₂₃₁ Hall element L₁₃₁, L₂₃₁ Excitation coil

Claims (1)

[Claims] 1. A pair of input terminals to which main and auxiliary DC power supplies are connected and which are connected in parallel to a load, and a pair of normally closed relay contacts provided between the input terminal and the load. And a pair of backflow prevention diodes respectively connected in parallel to the normally closed relay contacts, and respectively provided between the input terminal and the load, and detects a reverse current flowing from the load to the input terminal side. And a pair of reverse current detection sensors that open a normally closed contact by activating a relay on the side where a reverse current is generated.