JPS63171161A - Capacitor loading apparatus with ic part - Google Patents

Abstract

PURPOSE:To supply output voltage stably by causing an oscillation circuit stepping up DC voltage to stop merely charging a main capacitor and to continue oscillation, when a charging switch circuit is turned OFF. CONSTITUTION:A capacitor loading apparatus provided with an IC part 9 is composed of a DC power 1, a power switch 2, a power supply circuit 3 for the IC part 9, an oscillating circuit 4 stepping up the DC power 1, an operating voltage detection circuit 5, a switch motion control circuit 6, a charging switch circuit 7, a main capacitor 8 and an auxiliary capacitor 12. For a period while the control circuit 6 for the charging switch circuit 7 turns ON said switch circuit 7, the main capacitor 8 is charged with electricity and the switch circuit 7 is turned OFF to stop said charging if said period has elapsed. Also in this case, however, the oscillation circuit 4 continues its oscillation and the output of said oscillating circuit 4 is effectively used by other circuits and electric elements.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device in which a capacitor is a load, such as an electronic flash device that supplies electric charge stored in a capacitor to a flash discharge tube to emit light, and particularly relates to a device in which a capacitor is used as a load. The present invention relates to a device that can maintain an operating power supply for an IC section even when the voltage of a DC power supply drops during the process.

Conventional Technology In recent years, the development of large-scale integrated circuits (hereinafter referred to as ICs) has been remarkable, and they are widely used in various electronic devices, making electronic devices smaller and easier to operate, as well as at lower prices. making it effective.

Some electronic devices, such as electronic flash devices for photography, use a DC power source as a load with a capacitor charged by the output of a DC-DC converter. When the capacitor is being charged due to operation, the voltage of the direct current power source decreases, so if a direct current power source is used as the power source for an IC, there is a risk that various contents stored in the IC will be erased. .

Japanese Patent Application Laid-Open No. 58-102223 improves this problem.
There is a publication in which the capacitor that serves as the power source for the IC is charged by the power supply battery, and the voltage of the capacitor for the IC power supply decreases based on the decrease in the power supply battery as the load capacitor is charged. Detected by voltage detection circuit,
When the voltage of the IC power supply capacitor reaches a level that interferes with memory operation, the oscillation operation of the DC-DC converter is stopped to secure the IC power supply, and the DC-DC converter is stopped.
When the RE power supply capacitor recovers to a sufficient voltage due to the stoppage of the C converter, it detects the voltage of the ICi power supply capacitor and intermittents the oscillation of the DC-DC converter so that the DC-DC converter oscillates. I
C power is maintained.

Problems to be Solved by the Invention In the above conventional example, the IC power supply is secured while the load capacitor is being charged, but in order to secure the IC power supply, the DC-DC converter must be alternately oscillated and stopped. When the oscillation stops, the DC-DO converter naturally does not generate an output voltage, so the output voltage of the DC-DC converter is used, and unlike a capacitor load, the power supply battery does not deteriorate much. It is not useful for other circuits or other electrical elements that do not occur.

The present invention was made to improve this problem. During the charging process of the main capacitor, which is the load, the oscillation circuit that boosts the DC power supply continues to oscillate without stopping the oscillation operation, and The object of the present invention is to provide a device that can continue to stably supply the output voltage of an oscillation circuit to circuits and electric elements.

Means for Solving the Problems The present invention provides a power supply circuit that supplies operating power to an IC section;
A charging switch circuit for the main capacitor that is charged with the high voltage of the oscillation circuit that boosts the DC power supply, a 5'-/auxiliary capacitor that is charged by the output of the DC power supply or the oscillation circuit, and a predetermined charging voltage of the auxiliary capacitor. When the operating voltage detection circuit and the operating voltage detection circuit detect a predetermined charging voltage, they start operating, turn on the charging switch circuit, and ensure that the power supply voltage of the IC section supplied by the power supply circuit is the minimum required. The above object is achieved by including a switch operation control circuit for the charging switch circuit that keeps the charging switch circuit on for a predetermined period of time during which the charging switch circuit is lowered to the above level and then turns off the charging switch circuit.

The main capacitor is charged during the period when the switch operation control circuit of the charging switch circuit turns on the charging switch circuit, and after the on period, the charging switch circuit is turned off and charging to the main capacitor is stopped. However, when the charging switch circuit is off, charging of the main capacitor only stops, and the oscillation circuit itself continues to oscillate, and the output of the oscillation circuit can be effectively used by other circuits and electrical elements during that time. .

61, -7 Embodiment FIG. 1 is a basic block diagram of an embodiment of a capacitor load device equipped with an IC section of the present invention. In the figure, 1 is a DC power supply, 2 is a power switch, 3 is an IC operation control circuit, 7 is a charging switch circuit for charging or stopping the main capacitor of the load; 8 is the main capacitor; 9 is an IC section; SC is an auxiliary capacitor charged by the output voltage of the DC power supply 1 or the oscillation circuit 4;

In the device configured as described above, when the power switch 2 is turned on, the oscillation circuit 4 oscillates, and if the auxiliary capacitor Sa is now supplied with power from the DC power supply 1, the auxiliary capacitor SC starts charging, and this charging voltage When the operating voltage detection circuit 5 detects a predetermined value, the switch operation control circuit 6 starts operating based on the detection output, turns on the charging switch circuit 7 at the same time as the start of operation, and thereby the main capacitor 8 stops charging. Start.

7f, -7 When charging of the main capacitor 8 starts by turning on this charging switch circuit 7, the voltage of the DC power supply 1 also decreases as is well known, and as a result, the power supply voltage supplied to the section 10 by the power supply circuit 3 becomes It continues to decline.

On the other hand, the switch operation control circuit 6 starts operating upon detection of a predetermined voltage by the operating voltage detection circuit 5, and has a function of turning off the charging switch circuit 7 after a certain period of operation. If the period is set so that the power supply voltage is at least the minimum level necessary for the operation of the circuit a section 9, the voltage necessary for the operation of the IC section 8 is always maintained during the ON period of the charging switch circuit 7. This will ensure power supply.

Then, when the switch operation control circuit 6 operates for a predetermined period of time, the charging switch circuit 7 is turned off by the switch operation control circuit 6, charging of the main capacitor 8 is stopped, and the auxiliary capacitor/condenser is turned off again by the DC power supply 1. Charging of SC starts, but since the charging of the auxiliary capacitor SC only compensates for the decrease in SC during the charging period of the main capacitor 8, the voltage reaches a predetermined value in a short time and the operating voltage detection circuit 5 again operates the switch. The control circuit 6 starts operating, and thereafter charges the main capacitor 8 while repeating the above-described operation.

FIG. 2 is a specific circuit diagram of the block diagram of FIG. 1, and in the figure, the power supply circuit 3 includes a capacitor 1o that is charged from the DC power source 1, and a constant voltage circuit that makes the charging voltage of the capacitor 1o constant. 11 is an auxiliary capacitor charged by the constant voltage output of the constant voltage circuit 11 of the power supply circuit 3, and the charging voltage of this auxiliary capacitor 12 is the operating voltage detected by the operating voltage detection circuit 5. It is also the power supply voltage of 10 parts 9. As is well known, the oscillation circuit 4 mainly includes an oscillation transformer 2o having a primary winding 20-1, a secondary winding 2o-2, and an auxiliary winding 20-3, and an oscillation transistor 21, and detects an operating voltage. The circuit 5 includes a resistor 13.1 that divides the charging voltage of the auxiliary capacitor 12.
4, the switch operation control circuit 6 includes a comparator 16 to which the voltage generated by the resistor 14 and the reference voltage generated by the resistor 15 are applied, a comparator 17, and a switch operation control circuit 6 that responds to the output level of the comparator 16.
The charge switch circuit 7 is connected between the oscillation circuit 4 and the main capacitor 8, and is switched by the transistor 19 of the switch operation control circuit 6. It has 5CR22.

Next, the operation of the device of the present invention having the above structure will be explained using FIG. 4, which shows the voltage waveforms of the main capacitor and the auxiliary capacitor.

Now, when the power switch 2 is turned on at time T1 when the device is not in use, the capacitor 10 is charged by the DC power supply 1, a constant voltage is output from the constant voltage circuit 11, and the auxiliary capacitor 12 is charged as shown in FIG. 4B. is being charged. When the charging voltage of the auxiliary capacitor 12 reaches the value vZ at time T2, the voltage generated by the resistor 14 in the operating voltage detection circuit 5 exceeds the reference voltage generated by the resistor 15 applied to the other input terminal of the comparator 16, so the comparison is performed. The vessel 16 becomes L level,
Transistor 1, which had been conductive due to the H level until then
9 becomes non-conductive, a voltage is applied to the gate electrode of 5CR22, and 5(iR22 becomes conductive).

0t-7 When the power switch 2 is turned on, the oscillation circuit 4 oscillates, and the main capacitor 8 is charged via the 5CR22 with the high voltage generated from the secondary winding 20-2 of the oscillation transformer 2o. As shown in Figure A, it starts at point 2. 5
When charging of the main capacitor 8 starts due to the conduction of CR22, the voltage of the DC power supply 1 decreases as is well known, and the voltage drop of the DC power supply 1 is significant especially in the initial stage of charging. decreases, the output of the comparator 16 immediately reverses to H level, 5CR22 becomes non-conductive, charging of the main capacitor 8 immediately stops, and the auxiliary capacitor 12 is recharged, causing the output of the comparator 16 to go to the L level. As a result of the reversal of , 5CR22 becomes conductive and the main capacitor 8 is charged, so that the main capacitor 8 is charged in a short period.

However, the main capacitor 8 is not charged in a short cycle due to the combination circuit of the comparator 16 and the comparator 1 of the switch operation control circuit 9.

That is, the charging voltage of the auxiliary capacitor 12 is 11'
-7 When the output of the comparator 16 inverts to L level, the auxiliary capacitor 12
Even if the voltage of There is no intermittent charging of the condenser/sustainer 8, resulting in efficient charging. However, if the L level output of the comparator 16 is maintained for too long, the voltage of the auxiliary capacitor 12 will continue to drop while the main capacitor 8 is being charged. The following will occur and the memory contents will be erased.

However, the L level maintenance period of the comparator 16 is set in consideration of charging the main capacitor 8 and securing the minimum necessary power supply voltage of the IC section 9, and FIG. 4 shows that the period is T3-T2.
It has become. Therefore, during the time T2-'r3, the output of the comparator 16 maintains the L level, and during that time the transistor 1
9 is non-conductive and 5CR22 is conductive, the main capacitor 8 continues to charge, and on the other hand, the voltage of the auxiliary capacitor 12 decreases, but the minimum power supply voltage of the IC part 9 is also secured, and T5 At the point in time, the output of the comparator 16 is inverted to H level, and the transistor 19 becomes conductive.
No voltage is generated at the gate of SCR 2, the SCR 22 becomes non-conductive, and charging of the main capacitor 8 is stopped. 5C
Even if R22 becomes non-conductive, the oscillation circuit 4 continues to oscillate. If charging of the main capacitor 8 stops at time T3, the auxiliary capacitor 12 is charged again, but in this case, the charging only replenishes the voltage drop during the time 'r3'r2 when charging the main capacitor 8. It reaches VZ at T4 in a relatively short time, and as mentioned above, the comparator 16 is inverted to L level, the transistor 19 is non-conducting, and the 5
T5-T, where CR22 becomes conductive and the main capacitor 8 is charged again, and the output of the comparator 16 maintains the L level.
It is charged for 4 hours.

The main air conditioner 8 is thereafter being charged while repeating the above-described operation.

Although the auxiliary capacitor 12 also serves as a power supply for the IC section 9, there is no problem in using another 13'.-7 capacitor for power supply to the IC section 8.

FIG. 3 is an electric circuit diagram of another embodiment of the device of the present invention, and the same numbers as those in the previous embodiment have the same functions, and a detailed explanation thereof will be omitted.

In this embodiment, an auxiliary capacitor is connected to the output side of the oscillation circuit, and when the 5OR22 is conductive and the main capacitor 8 is being charged, the output of the oscillation circuit 4 flows into the main capacitor 8, and the auxiliary capacitor 23 is does not flow and the charging voltage of the auxiliary capacitor 23 decreases while the main capacitor 8 is being charged, so even if the auxiliary capacitor 23 is connected to the output side of the oscillation circuit 4, the same operation as in the previous embodiment can be performed. .

Effects of the Invention As described above, the device of the present invention maintains the oscillation operation of the oscillation circuit even if the power supply voltage of the IC section decreases during charging of the main capacitor, or even when charging of the main capacitor is stopped. Since there is no need to stop the oscillation circuit, the output of the oscillation circuit can be effectively used for other electric circuits and electric elements.

14'-.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of a capacitor load device equipped with an IC section of the present invention, FIG. 2 is a specific circuit diagram of the block diagram of FIG. 1, and FIG. 3 is another embodiment of the device of the present invention. Fig. 4 is a waveform diagram for explaining the operation of the embodiment shown in Fig. 2, and Fig. 4A shows the charging voltage of the main capacitor, and Fig. 4B shows the charging voltage of the auxiliary capacitor. FIG. 1...DC power supply, 3...Power supply circuit, 4
...Oscillation circuit, 5...Operating voltage detection circuit, 6...Switch operation control circuit, 7-...
・Charging switch circuit, 8...Main capacitor, 9.
...IC section, 12, 22, SC...auxiliary capacitor.

Claims (1)

[Claims] A DC power supply, an IC section, an oscillation circuit that boosts the DC power supply, and a main capacitor that is charged by the output of the oscillation circuit, and when turned on, the main capacitor is charged by the output of the oscillation circuit. a charging switch circuit;
an auxiliary capacitor that is charged by the output of the DC power supply or the oscillation circuit; a power supply circuit that supplies operating power to the IC section; an operating voltage detection circuit that detects a predetermined value of the charging voltage of the auxiliary capacitor; When the operating voltage detection circuit detects a predetermined value of the charging voltage of the auxiliary capacitor, the operation is started by the output of the operating voltage detection circuit, and the charging switch circuit is turned on to control the power supply circuit that supplies the power to the IC section. and a switch operation control circuit that keeps the charging switch circuit turned on during a predetermined period of time during which the supply voltage drops to a minimum necessary level, and turns off the charging switch circuit after the predetermined period of on operation. A capacitor load device equipped with an IC section.