JPS627776B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switching regulator type stabilized power supply device, and particularly to a power supply device having a function of easily identifying an overvoltage abnormality during parallel operation. This will be explained below using the drawings.

FIG. 1 is a block diagram showing a conventional example of this type. In the figure, A1 and A2 are unit switching regulators (hereinafter referred to as power supply units). B1 and B2 are overvoltage detection circuits built into the power supply units A1 and A2, respectively. Detects overvoltage in power supply units A1 and A2, respectively, and sends overvoltage detection (power supply stop) signals S1 and S2 to the corresponding power supply units A1 and A2 to stop operation of the corresponding power supply units, and simultaneously outputs the signals S1 and S2. are inserted into each other via the common line S3, and the operation of the other power supply unit A1 or A2 is stopped. R is a common load of power supply units A1 and A2. The power supply units A1 and A2 each have a voltage control circuit (not shown) and are configured to supply a stabilized output Eo to the load.

Therefore, when the overvoltage detection circuit B1 detects an overvoltage when the power supply units A1 and A2 are operated in parallel, the detection circuit B1 outputs a signal S1 to stop the operation of the power supply unit A1, and at the same time, the common line S
3, the power supply unit A2 is also stopped.

That is, since the output voltage Eo has two overvoltage detection functions, it is possible to improve the reliability of the device. In addition, by setting the number of power supply units in parallel to N, it is possible to have an N-fold overvoltage detection function, and by monitoring the signal on the common line S3 from outside the power supply, it is possible to detect when the power supply unit has stopped operating due to overvoltage. can be determined. However, this circuit cannot determine which power supply unit is generating the overvoltage.

That is, since the overvoltage detection circuits B1 and B2 are connected to the same load line, the output voltage Eo is applied to both of them. Therefore, regardless of whether the overvoltage is caused by either power supply unit A1 or A2, when the output voltage Eo rises to the overvoltage range, the overvoltage detection circuit B1 or B2, whichever has the lower detection voltage setting value, will detect the overvoltage. This is to output a signal. Therefore, even if the signal S1 or S2 is monitored from the outside, it is impossible to identify a faulty machine. Therefore, conventionally, as shown by the dotted line in FIG.
2 was provided to prevent each machine from turning around, thereby identifying a faulty machine. However, in this case, when the output current of each power supply unit is large, the power loss due to the diode D1 or D2 is large and it is uneconomical, and there are disadvantages such as an increase in the size of the device due to heat treatment and mounting.

The present invention eliminates such drawbacks and provides a power supply device that is inexpensive, economical, and allows easy identification of a faulty device. The present invention is characterized in that each power supply unit is provided with an output pulse detection circuit, a logic circuit that takes logic between the overvoltage signal and the output pulse signal, and the overvoltage signals are connected through a common line. . This will be explained below using the drawings. FIGS. 2 and 3 are circuit diagrams of an embodiment of the present invention and operation waveform diagrams of each part thereof, in which the same reference numerals as in the conventional example indicate equivalent parts. In Fig. 2, A1 and A2 are switching regulators (power supply units), 1 is an AC power supply, 2 is a full-wave rectifier circuit, 3 is a switching transistor, 4 is an output transformer, and 5 is a rectifier and smoothing circuit. A current is alternately passed through the output transformer 4 through the on/off operation of step 3, and a rectangular waveform alternating current output e0 is sent out.The rectifying and smoothing circuit 5 converts this into direct current and applies it to the load R in a well-known operation. C
The voltage control circuit compares the output voltage with the reference voltage, controls the conduction width of the transistor 3, and performs the well-known operation of stabilizing the load voltage. Next, B1 is an overvoltage detection circuit that detects the output voltage E0 using a resistor R1 and a constant voltage diode DZ as shown in Figure 2b. When a predetermined voltage is reached, the transistor Q1 and thyristor SCR are turned on to detect the overvoltage (or stop operation). )
A signal S1 is output. F1 is an output pulse detection (discrimination) circuit, which is provided with an output pulse detection winding nd in the output transformer 4 as shown in FIG. The charging/discharging voltage is set to a higher potential than the reference power source ES during steady state (with pulses), so that the comparator COP outputs a low level output signal S5. G1 is a logic circuit that takes the logic between the overvoltage signal S1 and the output signal S5, and generates a failure machine determination signal S4-
Sends 1. The circuit of the present invention is configured as described above.

Next, the operation will be explained with reference to FIG.
First, under normal conditions, power supply units A1 and A2 supply a stable output E0 to the load. (Fig. 3a) Then, when an overvoltage cause occurs in the power supply unit A1 at time t1, the output voltage increases.
Then, at time t2, the voltage changes to power supply unit A.
2, the unit A2 will not provide any output. Therefore, no output pulse is detected in the pulse detection circuit F2 of the power supply unit A2. (Fig. 3c) Therefore, in the comparator of the detection circuit F2, the reference power supply becomes high potential, and the signal S
5 stops sending. (Fig. 3 d) (Fig. 3 d)
In this example, the signal S5 stops after a time limit t2' from the stop of the output pulse. )
On the other hand, when the output voltage of power supply unit A1 further increases and reaches the overvoltage detection voltage value E0'' at time t3, transistor Q1 and thyristor SCR of overvoltage detection circuit B1 (or B2) become conductive (at time t
4) and outputs the overvoltage detection signal S1. (3rd
Figure f) The signal S1 is also input to the logic circuit G2 of the other power supply unit via the logic circuit G1 and the line S3. Therefore, in the pulse detection circuit F1 of the power supply unit A1, in order to detect the pulse output until time t4 as shown in FIG. 3b, the comparator COP
sends the signal S5 as shown in Fig. 3e to the logic circuit G.
Enter 1.

Therefore, in the logic circuit G1, the time t4 to t5
A logic is established between the two and the failure determination signal S4-1
(Figure 3g). The other power supply unit A2
In this case, the logic is not established and the signal S4-2 is not sent out. In other words, by monitoring the discrimination signal S4-1 or S4-2, it is possible to easily identify an overvoltage failure machine.

In the above embodiment, an example in which two power supply units are operated in parallel has been described, but it is clear that the same implementation can be carried out even if more power units are installed. As is clear from the above description, according to the present invention, it is easy to identify an overvoltage malfunctioning machine, so it can be quickly replaced with a normal spare machine, and the holding operation of the machine is smooth, as well as the power loss of the machine. It has great practical effects, such as being small in size, economical, etc.

[Brief explanation of the drawing]

Figure 1 is a conventional circuit diagram. FIGS. 2a and 2b and 3 are circuit diagrams of an embodiment of the present invention and operation waveform diagrams of each part thereof. In the figure, A1 and A2 are switching regulators (power supply units), B1 and B2 are overvoltage detection circuits, R is load, D1 and D2 are diodes, C is voltage control circuit, F1 is pulse detection circuit, and 1 is AC power supply. ,, 2 is a full-wave rectifier circuit, 3 is a switching transistor, 4 is an output transformer, 5 is a rectifier and smoothing circuit, G1 is a logic circuit, nd is a pulse detection winding,
COP is a comparator, Es is a reference power supply, Dz is a constant voltage diode, Q1 is a transistor, SCR is a thyristor, S1 and S2 are overvoltage detection (stop) signals, S3
is a common line, S4-1, S4-2 are discrimination signals, S5
is the pulse detection signal and Eo is the output (load) voltage.

Claims (1)

[Claims] 1. In a stabilized power supply device in which a plurality of switching regulators equipped with a voltage control circuit and an overvoltage detection circuit are operated in parallel, each of the switching regulators has an output pulse detection circuit and a detection circuit for the overvoltage detection circuit. A logic circuit is provided to take logic between the signal and the pulse signal of the output pulse detection circuit, and the detection signal is connected through a common line, and when an overvoltage occurs, the switching regulator is identified by the output signal of the logic circuit. A switching regulator type stabilized power supply device characterized in that each switching regulator is configured to stop the power supply.