JPH037031A - Battery connected power supply circuit - Google Patents

Abstract

PURPOSE:To automatically connect a battery when an AC input is extinguished by forming an automatic switching circuit by using a PNP transistor and an NPN transistor. CONSTITUTION:The main part of a power supply circuit is composed of a PNP transistor(Tr) 1, NPN Tr 2 and 3, registers 4 and 6, a transformer 6, a rectifying circuit 7, a rectifier 8, a capacitor 9 and a battery 10. When the capacitor 9 is not yet charged, the collector terminals of Tr 2 and 3 are opened and Tr 1 is also opened. When an AC input is connected to input terminals A and B, the capacitor 9 is charged and a power, is supplied to output terminals C and D. When the AC input is cut off, the charging current of the capacitor 9 flows into the base of the Tr 2 via the register 4 to activate Tr 1 and 2, directly connecting the battery 10 to the DC current output terminals C and D to supply the power.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a rectifier circuit in which the output of a rectifier circuit for converting AC input into DC is conductive on the anode side, which is connected in series to the first DC output terminal of the anode. The present invention also relates to a battery connection power supply circuit that is directly connected to the second DC output terminal of the cathode on the cathode side, and connects a capacitor and a battery in parallel between the two DC output terminals.

[Conventional technology]

Conventionally, this type of battery-connected power supply circuit has had a configuration in which a battery and a switch are connected in series to a DC output terminal.

This will be explained with reference to FIG. FIG. 2 is a circuit diagram showing a conventional example. According to FIG. 2, this power supply circuit has input terminal A for AC input.

B and DC output output terminals C, D, and transformer 6
, a rectifier circuit 7, rectifiers 8 and 12, a capacitor 9, a battery 10, and a switch contact 11.

The transformer 6 connects the AC inputs of input terminals A and B to the primary winding, and converts the output of the secondary winding into a predetermined voltage. The rectifier circuit 7 inputs the output of the transformer 6, converts it into direct current, and outputs it. The rectifier 8 is connected in series between the anode side of the rectifier circuit 7 and the DC output output terminal C, and the current direction to the output terminal C is the conduction direction. A capacitor 9 has both terminals connected between output terminals C and D to smooth the DC output. Battery 10. Switch contact 11. and rectifier 12 are connected in series between output terminals C and D, and rectifier 12 is connected in series between output terminals C and D.
It is in a conductive state in the direction of .

The switch contact 11 is connected to an AC input, and after the capacitor 9 is charged, forms a closed circuit to which the battery 10 is connected manually or automatically.

[Problem to be solved by the invention]

As mentioned above, conventional battery-connected power supply circuits are configured to connect the battery via switch contacts, so in consideration of battery consumption, the AC input is connected to complete charging of the smoothing capacitor. There was a problem in that it required a switch contact that would later form a closed circuit, and the timing of connection was unclear.

An object of the present invention is to provide a battery-connected power supply circuit that solves the above problems by forming an automatic switching circuit using transistors.

[Means to solve the problem]

In the battery-connected power supply circuit according to the present invention, the output of a rectifier circuit that converts AC input into DC is connected to the first DC output terminal via the rectifier in the conducting direction on the anode side, and directly to the second DC output terminal on the cathode side. each connected to the output terminal, and the first
and a battery connected power supply circuit in which a capacitor and a battery are connected in parallel between the second DC output terminal,
a PNP type first transistor having an emitter terminal directly connected to the anode terminal of the battery and a collector terminal directly connected to the first DC output terminal; and a second NPN transistor whose emitter terminal is directly connected to the second DC output terminal, and a third NPN transistor whose collector terminal and emitter terminal are directly connected to the base terminal and emitter terminal of the second transistor, respectively. a first resistor having one terminal connected to the cathode terminal of the first transistor and the other terminal connected to the base terminal of the second transistor; and a second resistor, the other terminal of which is connected to the base terminal of the transistor, and the other terminal of which is connected to the anode terminal of the rectifier circuit, respectively.

〔Example〕

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

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

In FIG. 1, the same components as those shown in FIG. 2, which were explained in the section of the prior art, are given the same reference numerals and their explanations will be omitted.

The power supply circuit shown in FIG. 1 uses transistors 1 and 2° 3, resistors 4 and 5, a transformer 6, a rectifier circuit 7, a rectifier 8, a capacitor 9, and a battery 10 to convert AC input from input terminals A and B to output terminals C and D. outputs stable direct current.

The transistor 1 is of PNP type, and has an emitter terminal connected to the anode terminal of the battery 10, a collector terminal connected to the output terminal e, and a base terminal connected to the collector terminal of the transistor 2.

Transistor 2 is an NPN type, with its collector terminal connected to the gate terminal of transistor 1, and its emitter terminal connected to battery 10.
The cathode terminal and output terminal of the transistor 3 are connected to each other, and the base terminal is connected to the collector terminal of the transistor 3.

Transistor 3 is an NPN type, with its collector terminal connected to the base terminal of transistor 2, and its emitter terminal connected to the output terminal.
Further, the base terminals are each connected to one terminal of the resistor 5.

The resistor 4 has one terminal directly connected to the collector terminal of the transistor 1 and the other terminal directly connected to the base terminal of the transistor 2.

The resistor 5 has one terminal connected to the base terminal of the transistor 3,
Further, the other terminals are connected to the anode terminals of the rectifier circuit 7, respectively.

Transformer 6, rectifier circuit 7. Rectifier 8 and capacitor 9
The circuit configuration including input terminals A and B for AC input and output terminals C and D for DC output is the same as that of the prior art described with reference to FIG.

Next, the first operation of the circuit shown in FIG. 1 will be explained.

First, a state in which there is no AC input and the capacitor 9 is uncharged at the time of shipping and delivery will be described.

Since capacitor 9 is uncharged, the potentials at both terminals are equal. One terminal of the capacitor 9 is directly connected to the pressure terminal C2, the emitter terminal of the rectifier 8, one terminal of the resistor 4, and the collector terminal of the transistor 1, and the other terminal is connected to the output terminal, and the emitter of the transistors 2 and 3. It is directly connected to the terminal and the cathode terminal of the battery IO. The potential is that the anode terminal of battery IO is connected to the emitter terminal of transistor 1, but the emitter terminal of transistors 2 and 3 is
Since the potential difference between the bases is zero and the transistors are in the cutoff region, the collector terminals of transistors 2 and 3 are open, and transistor 1 is in an open state.

Further, when an AC input is connected to input terminals A and H, the rectifier circuit 7 outputs a DC voltage and charges the capacitor 9. The anode terminal of the rectifier circuit 7 is connected to the base terminal of the transistor 3 via the resistor 5, and the cathode terminal of the rectifier circuit 7 is connected to the emitter terminal of the transistor 3 through the resistor 5. A direct current circuit is formed through this. Since the potential difference between the collector terminal and the emitter terminal of the transistor 3 is reduced by activation, the transistor 2 is still in the cut-off state, and therefore the transistor 1 also maintains the open circuit of the output circuit of the battery IO.

Next, the state when the AC input disappears will be explained. The rectifier circuit 7 and the transformer 6 have a small direct current resistance of almost zero at the output terminal of the rectifier circuit 7, and therefore, the transistor 3 has a small potential difference between the base and emitter and becomes a cutoff region, so that the collector and emitter are opened. To open the collector-emitter of the transistor 3, the output terminal C is connected to the base terminal of the transistor 2 via the resistor 4, and the output terminal C is connected directly to the emitter terminal of the transistor 2, respectively. Since there is a potential difference between the output terminals C and D due to the charged capacitor 9, the transistor 2 is activated and driven, and the base terminal of the transistor l connected to the collector terminal of the transistor 2 is driven, and the transistor 1 becomes conductive. Then, the battery 10 is directly connected to the DC output terminals C and D to supply power.

In other words, when the AC input disappears, since the capacitor 9 is charged, the DC output is automatically transferred to the battery 1.
0 supplies, while capacitor 9 is uncharged, batch! J-10 is isolated from the DC output circuit by a transistor.

〔Effect of the invention〕

As explained above, the battery-connected power supply circuit of the present invention requires a configuration in which the battery is automatically connected to the DC output of the rectifier circuit when the AC input disappears using a switch circuit formed by a transistor. So,
At the R period after the battery is turned on, predetermined conditions are set by selecting transistors and resistors, thereby making it possible to eliminate the need for manual switching operations. Furthermore, the transistor switching circuit has low loss, and if the capacitor is uncharged before shipping, there is no circuit that consumes the onboard battery, and there is no need for a manual switch contact or an automatic drive circuit for the switch contact.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional example. 1.2.3...transistor, 4,5...
...Resistor, 6...Transformer, 7...
Rectifier circuit, 8, 12... Rectifier, 9...
・Capacitor, 10...Battery

Claims (1)

[Claims] An output of a rectifier circuit that converts AC input into DC is connected to a first DC output terminal via a conduction direction rectifier on the anode side and directly to a second DC output terminal on the cathode side, respectively,
In a battery-connected power supply circuit in which a capacitor and a battery are connected in parallel between the first and second DC output terminals, the PNP has an emitter terminal directly connected to the anode terminal of the battery, and a collector terminal directly connected to the first DC output terminal. a second NPN transistor whose collector terminal is directly connected to the base terminal of the first transistor, and whose emitter terminal is directly connected to the cathode terminal of the battery and the second DC output terminal; a third NPN transistor whose collector terminal and emitter terminal are directly connected to the base terminal and emitter terminal of the second transistor; one terminal is connected to the cathode terminal of the first transistor, and the other terminal is connected to the cathode terminal of the first transistor; a first resistor connected to the base terminal of the second transistor, and a second resistor, one terminal of which is connected to the base terminal of the third transistor, and the other terminal of which is connected to the anode terminal of the rectifier circuit. A battery-connected power supply circuit comprising: