JPS6041413B2 - Fuse blowing method - Google Patents

Description

Detailed Description of the Invention: '1 - Technical Field of the Invention The present invention relates to a method for blowing out a fuse in a printer, for example, and in particular, in order to quickly blow out a fuse when an abnormality is detected, a load is forced to blow out the fuse. This invention relates to a fuse that increases the fuse current by controlling the on state.

■ Conventional technology and problems For example, in printers, as shown in Figure 1, there are magnets for driving dot pins (there are as many dot pins, but only one magnet Mg is shown), and a motor for paper feeding. A plurality of electromagnetic devices such as a ground and a carriage motor Mn are provided.

In order to operate these electromagnetic devices, drivers such as switching transistors Do...Dn...
・Dg (four drivers are used if a four-phase pulse motor is used for paper feeding) is provided, and by selectively controlling these drivers by the control circuit 1, paper feeding can be controlled and predetermined characters can be printed. or print it. The operation of the drivers Do...Dn...Dg, etc. is monitored by the driver check circuit 2, and when an abnormality occurs in even one of the drivers, the fuse blowing circuit 3 is controlled and the fuse F is A current is forced to flow to forcibly blow it out, and the power to the printer is turned off, thereby preventing further undesired malfunctions of the printer from occurring due to the abnormality. In this case, the fuse blowing circuit uses a switching element with a large current capacity such as an SCR, and the output of the driver check circuit 2 turns on this switching element and causes a current to blow the fuse F to flow.

In this conventional method, the larger the capacitance of the load connected to the fuse F', or the more loads that operate simultaneously, the larger the fuse capacitance becomes. The fuse blowing time is also long, which may lead to destruction of the elements or load used in the fuse blowing circuit.

'3} Object of the Invention In order to improve the above-mentioned problems, it is an object of the present invention to provide a method for blowing a fuse in which the fuse blowing time is shortened when an abnormality occurs in the driver.

'41 Structure of the Invention In order to achieve this object, the fuse blowing method of the present invention includes a plurality of drivers, a driver check circuit that checks the operating state of each driver, a control circuit that controls the operation of each driver, and a driver check circuit that checks the operating state of each driver. In a device equipped with a fuse connected to a power supply circuit, when the driver check circuit detects an abnormality, the fuse is forced to operate by forcibly operating another driver that can blow the fuse by flowing a drive current. It is characterized by being made to melt.

Wind Examples of the invention An embodiment of the present invention will be explained with reference to FIG.

In FIG. 2, the same reference numerals as in FIG. 1 indicate the same parts,
10 is a control circuit. Similarly to the control circuit 1 in FIG. 1, the control circuit 10 controls the driver D according to the control signal.
In addition to selectively controlling o, Dn, Dg, etc. to perform predetermined printing on print paper, the driver check circuit 2
The output turns on some of the drivers Do to Dg.

Therefore, in FIG. 2, when the driver check circuit 2 detects an abnormality in some of the drivers Do to Dg, the abnormality detection signal is sent to the fuse blowing circuit 3 and the control circuit 10.
to inquire.

As a result, the fuse blowing circuit 3 turns on the switch element so that a large current flows through the fuse F, and also turns on a part of the control circuit 1 and the driver Do to Dg. Therefore, the current flowing through the fuse F is added to the current flowing through the fuse blowing circuit 3, and the current flows through the drivers Do to D.
By turning on a part of g, a current flows, and as a result, the fuse blowing time can be shortened, so it is possible to reliably prevent damage to the fuse blowing circuit and the load. The element capacitance can be reduced, and the fuse capacitance can be easily determined. When the driver check circuit 2 transmits the abnormality detection signal to the control circuit 10', instead of turning on some of the drivers 0o to Dg, all of them may of course be turned on.

Incidentally, the capacity of the fuse is set to be greater than the current when the load is driven at its maximum capacity.

Also, the number of loads to be driven is smaller than the total number of loads. In other words, in a printer, when the magnet for driving the dot pins for printing is operating, the paper feeding mode does not operate, so normally the entire load is not driven at the same time, and therefore the current capacity of the fuse is also reduced. This point is taken into consideration and determined by the load currents that may be driven at the same time. Therefore, by controlling as described above, fuse F can be quickly blown out.
Next, a second embodiment of the present invention will be described with reference to FIG.

In FIG. 3, the fuse blowing circuit 3 in FIG. 2 is omitted, and when an abnormality detection signal is transmitted from the driver check circuit 2, the control circuit 20 is connected to the driver D.

~Dn~D6 are all turned on. Of course, in the control circuit 20, similarly to the control circuit 10 in FIG. 2, the drivers Do to Dg are selectively controlled based on control signals so as to perform predetermined dot pin printing during normal operation. However, when the abnormality detection signal is output from the driver check circuit 2, the control circuit 2 turns on all the drivers Do to Dg and forcibly blows out the fuse F, as described above. By doing so, a fuse blowing circuit can be made unnecessary. Of course, instead of turning on all the loads connected to fuse F' in FIG. 3, it is also possible to turn on some of the drivers in response to the abnormality detection signal from driver check circuit 2 and blow fuse F. .

'6' Effects of the Invention According to the present invention, when an abnormality is detected in the driver, the driver is forcibly turned on and the current flowing through the fuse is controlled to be higher than the blowing current, so that the fuse is reliably blown. can be done.

However, by operating a driver in addition to the fuse blowing circuit, the capacity of the fuse blowing circuit can be reduced, and the fuse can be blown more reliably.

[Brief explanation of the drawing]

FIG. 1 is a conventional fuse blowing method, FIG. 2 is a block diagram of one embodiment of the present invention, and FIG. 3 is a block diagram of another beautiful embodiment of the present invention. In the figure, 1 is a control circuit, 2 is a driver check circuit, and 3 is a control circuit.
1 is a fuse blowing circuit, and 10 and 20 are control circuits. ★'Z diagram 3 diagrams

Claims (1)

[Scope of Claims] 1. A device comprising a plurality of drivers, a driver check circuit that checks the operating state of each driver, a control circuit that controls the operation of each driver, and a fuse connected to a power supply circuit of the drivers, Fuse blowing characterized in that when a driver check circuit detects an abnormality, another driver capable of blowing the fuse is forcibly operated by flowing a drive current to forcibly blow the fuse. Method. 2. A patent characterized in that a fuse blowing circuit is provided, and when the driver check circuit detects an abnormality, the fuse blowing circuit is operated to flow a fuse blowing current, and a driver is also operated to increase the current flowing to the fuse. A fuse blowing method according to claim 1.