JPS58190274A - Power source circuit - Google Patents

Abstract

PURPOSE:To notify whether a load is energized or not by providing an energization detecting transistor circuit at the output terminal of a DC power source generator and emitting a light from a light emitting element by this operation. CONSTITUTION:A load is connected to an output terminal DC.OUT, and when a load current is flowed, a current ID flows through a diode 11 and a resistor 12, with the result that a voltage drop occurs between the connecting points A and B. Thus, a transistor 14 is conducted, a current is supplied to the collector, thereby allowing an LED16 to light. In this manner, the operation of the load can be notified by the lighting of the LED16.

Description

[Detailed description of the invention] This invention relates to a power supply circuit.

In conventional AC adapters, light-emitting elements such as LEDs (light-emitting diodes) are used to control the energized state (IIC standby state).
There was something that was designed to notify you of 1). In other words!
In Figure 1, AC-IN is a console plug,
1 is a voltage conversion transformer, 2 is a rectifier circuit, 3 is a smoothing circuit, 4Fi current limiting resistor, 5 is LEDlD C-0Lr
r is the output terminal, and 6.6゜v>41 Puffer IN is plugged into the outlet, and the commercial power supply 10 is connected to the primary shaft of the voltage conversion transformer.
When 0V is supplied, the rectifier circuit 2 and smoothing circuit 3iC generate the output terminal DC.01JT[l[ffi voltage. As a result, LED 5 lights up through 4 resistors.

However, this AC adapter has an output terminal DC/o.
If the companion load connected to u'r is operating, it remains lit regardless of whether it is connected to u'r or not. That friend, the load is l12I work 1
The drawback was that it was not possible to report whether or not the

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a power supply circuit that indicates whether or not a load is energized.

An embodiment of this invention is shown in Figure @2. That is, in the figure, 6 is a voltage conversion transformer, 7 is a rectifier circuit, 8 is a smoothing circuit, 9 is a current limiting resistor, 10 is an LED for displaying a stiff pipe, and a PNP for detecting the current flow of IIVi. '7 VBK (base-emitter voltage) guarantee diode for transistor 14, 12.13.15Vi resistance, 16 is in working condition! I
This is a display LED.

Actions [To explain, the actions numbered from 6 to 10 are the first
It is exactly the same as the one explained in the figure.

Now, if no load is connected to the output terminal DC/OUT and no current is flowing through the load, the diode 11 and the resistor 12, through which no current flows, the transistor 14 will not conduct, and therefore the LED 16 will not light up. Next, a VC load is connected to the output terminal (DC/0UT), and when the load current flows, a voltage fJ is applied to the diode 11 and the resistor 12.
tID flows, resulting in a voltage drop between connection points A and B. At this time, the characteristics of the anode-cathode voltage VD of the diode 11 and VBK of the transistor 14 are exactly the same (for convenience, the voltage drop at the condensation point B is the voltage drop at the point A
In terms of t, it becomes equal to or higher than VBFi, and the transistor 14 for that purpose is turned on, current is supplied to the reference, and the LED 16 lights up. In this way, this LED
16 lights up to warn that the load has operated. Moreover, by adding a simple circuit to the conventional ACC adapter, 09! It is possible to express and be useful.

As described above, the power supply circuit of the present invention has a direct current chamber
This operation causes all of the light emitting elements to emit light, so
j[When current flows, the light-emitting element lights up to notify that the load is operating, which is extremely convenient.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a conventional example, and FIG. 2 is a circuit diagram of an embodiment of the present invention.

Claims (1)

[Claims] A DC power supply generator, an energization detection transistor circuit that is inserted into the output 1IrC of this generator and turns on when it detects energization to a load connected to its output terminal; A power supply circuit equipped with a light-emitting element that emits light according to its operation.