JPS6248458B2 - - Google Patents

Description

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

Some copying lamps used in so-called PPC copying machines and the like are required to turn on the lamps at the same time as the copying original or lamp is moved (motor driven). In order to meet these requirements, conventional circuit configurations required the lamp lighting circuit to always close the preheating circuit during the start stage, and for this reason, separate switches were provided for the lamp lighting circuit and the motor drive circuit. It was necessary to interlock them and close the circuit almost simultaneously. As a result, there was a drawback that two switches were required.

Therefore, an object of the present invention is to provide a power supply circuit that can operate a load that requires preheating and other loads with a single switch.

An embodiment of the invention is shown in the drawings. That is,
In this power supply circuit, the winding directions of the primary coil 2 and secondary coil 3 of the leaky transformer type ballast 1 are the same, and a switch 4 is connected between them to form a series circuit. Connect the power supply 5 and connect the primary side circuit
A phase advance capacitor _Xc and a lamp L are connected to both ends of the series circuit of the secondary coil 3 and switch 4.
A series circuit of 1 is connected to form a phase advance lighting secondary circuit Y, and preheating coils 6 and 7 are connected to the primary coil 2 and connected to both ends of the lamp L (not shown).
A motor M is connected to both ends of a series circuit of the secondary coil 2 and the switch 4 to form a load circuit Z.

The operation of this circuit will be explained next. When the switch 4 is turned on, the secondary circuit Y and the load circuit Z become closed circuits, the lamp L is preheated, so it lights up quickly, and the motor M is driven at the same time. On the other hand, when the switch 4 is turned off, the lamp L is always preheated by the induced voltage generated in the preheating coils 6 and 7 because the power supply 5 is connected to the primary coil 2, but the secondary circuit Y and the load Since both circuits Z are opened by switch 4, they do not operate. However, in this case, the secondary circuit Y and the load circuit Z form one loop, and the circuit configuration is such that the power supply voltage is applied to the primary coil and an induced voltage is generated in the secondary coil. 2 and secondary coil 3 have the same winding direction and are connected to switch 4, so each voltage direction (arrow)
is reversed in the loop circuit, and the differential voltage is only applied to the motor M, lamp L, and phase advance capacitor, and no abnormality occurs. For example, if the power supply voltage is 100 volts, the induced voltage in the primary coil 2 is 100 volts, and the induced voltage in the secondary coil 3 is 70 to 150 volts, depending on the design of the ballast, then the voltage generated in the loop circuit is (70-150) −100
= -30 to +50 volts, and only 50 volts is generated at most. This is the constant of electric motor M,
Although the degree of damage varies depending on the constant of the phase advance capacitor _Xc and the degree of the induced voltage, the ballast 1 and the windings of the motor M will not be burnt out. Therefore, the lamp L can be maintained in a state where it cannot be lit, and the loop circuit can be equivalently interrupted.

Note that this circuit is applicable not only to lamps that require preheating, but also to other loads that require preheating during operation, such as X-ray photography, and other loads that operate simultaneously.

As described above, in the power supply circuit of the present invention, the winding direction of the primary coil and the secondary coil are the same and the switch is connected in series between them, and the A load is connected, a second load is connected across the series circuit of the primary coil and the switch, and a power supply is connected to the primary coil, so one switch can preheat the first and second loads. Since the required load and other loads can be operated at the same time, the circuit components and circuit configuration are simplified, and there is an effect that abnormal operation does not occur.

[Brief explanation of the drawing]

The drawing shows a power supply circuit for driving a lamp and a motor according to an embodiment of the present invention. 2...Primary coil, 3...Secondary coil, 4...
Switch, 5...Power supply, L...Lamp (first load), M...Motor (second load), X...Primary side circuit, Y...Secondary side circuit, Z...Load circuit .

Claims (1)

[Claims] 1. A series circuit in which the primary coil and secondary coil are wound in the same direction and a switch is connected between them.
A primary side circuit is formed by connecting a power source to the primary coil of this series circuit, and a second side circuit is formed by connecting a first load between the secondary coil of the series circuit and both ends of the switch.
A power supply circuit comprising a next-side circuit and a load circuit formed by connecting a second load between both ends of the switch and the primary coil of the series circuit.