SU1177832A1 - Device for electrical protection of printing head - Google Patents

Description

The invention relates to the automation of computing and can be used in information output devices, in which the printing elements are made in the form of electromagnets. '.

The purpose of the invention is to shorten the time for troubleshooting.

Figure 1 shows the functional diagram of the device; 2 a timing diagram of the operation of the device.

. The device contains a printing unit 1, an indication unit 2, a power-off unit 3, a control unit 4, an analysis unit 5, a code generation unit 6, a register 7, a buffer 8, a control unit 9, a group of elements 10 of one-sided conductivity.

The print block contains a group of printing elements 11 and a group of keys 12,

The analysis unit contains a comparator 13, the first trigger 14, the first element And 15, the element 16 voltage stabilization, matching element 17.

The code generation unit contains the second trigger 18, the second element And 19, the counter 20.

2

The control unit contains the third 21 and fourth fourth triggers.

The device works as follows.

 5 In the initial state, after power on, all the triggers are in the zero state, the state of the remaining elements and blocks is indifferent,

10 In the print mode, the parallel inputs of the register 7 feed in parallel the information to be printed. From the outputs of the register, the information goes to buffer 8, where it

15 is gated by the T2 signal and then goes to the thyristor bases of the printing unit 1. In the collector circuit of transistors are included the windings of the electromagnets of the printing elements 11, which operate and provide an imprint on paper in accordance with the information received.

If in the print mode any element of the printing unit fails, for example, a short circuit in the electromagnet winding, the control unit 4 will generate a low level "Alarm" signal, which goes to the first output of the device and informs the external device about the malfunction.

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From this moment on, the device goes automatically to the search mode for the faulty item. The control unit is started, which generates the TK and T4 signals. five

The TOR signal clears the register 7, resets the counter 20 to the initial state and sets the trigger 18 to the single state. At the output of the trigger 18, a signal is generated

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The search that enters the input of the power-off unit 3, thereby providing power to the printing unit. In addition, the signal enters the register 7, translating it into the sequential shift mode, and the device output, informing the external device about the start of the automatic troubleshooting.

The signal T4 is recording. 20 single signal to register 7.

On the falling edge of the pulse T1, a single signal appears at the first output of the register 7 of the RM (Fig. 2), which is gated by the pulse T2 and arrives at the base of the first transistor. In addition, the pulse T2 through the element And 19 passes to the counting input of the counter 20 (FIG. 2 CT-5) and changes its state.

The signal T2 on the first element of the print block is formed pulse "Out, 1" (Fig. 2). This impulse passes through element 10 (FIG. 2, CT-1) and is fed to the input of the analysis unit 5. · Suppose the first element of the print unit is healthy, its EMF of self-induction triggers the comparator 13

and reset trigger 14 to its original state.

The next pulse T1 does not pass through the element 15, and its back edge sets the trigger 14 to the single state and moves the single signal to the output of Pr2 (figure 2) further, according to the signal T2, the actions are repeated as described.

By the third pulse T1 and T2, the third faulty element of the printing unit is excited, the EMF of self-induction of the faulty element is significantly below the norm, therefore the comparator 13 will not work and the trigger 14 will remain in the unit state.

In this case, the next impulse ΤΙ passes through the element I 15 (FIG. 2, CT-4) and resets the trigger 18 to the initial state. The search for the faulty element is completed, the code of the number of the faulty element is stored at the outputs of the counter 20, which is displayed on the display unit 2 and is fed to the output of the device for information. mirovaniya external device.

The device can operate in an additional diagnostic mode. In this case, the control unit 9 is started with a short single pulse T5 from an external device. The duration ^{0 of the} pulse T5 must not exceed the repetition period T1. Otherwise, this mode is similar to the fault finding mode. If the device does not contain defective elements of the block, it returns to its original state when the counter 20 overflows.

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Claims (4)

1. DEVICE FOR ELECTRICAL PROTECTION OF PRINTING HEAD, containing display unit, power off unit, control unit, group of unilateral conductivity elements, inputs of control unit connected to cathodes of unilateral conductivity elements and are inputs of the first group of device, output of control unit is connected to input of display unit and the first input of the power-off unit, the third input of which is connected to the positive pole of the power supply, and the output is the third output of the device, characterized in that in order to shorten the time of troubleshooting, an analysis block, a code generation unit, a register, a buffer, a control unit, inputs of a parallel register code are entered as inputs to the second device group, a register synchronous input, a second input of the analysis unit and a second input of the control unit are the first input of the device , the serial input of the register is connected to the second output of the control unit, the first output of which is connected to the reset input of the register and the second input of the code generation unit, the outputs of the register are connected to the inputs of the group the input, which input and the third input of the code generation block are the second input of the device, the buffer outputs are the outputs of the first group of the device, the first input of the analysis block is connected to the anodes of the unilateral conductivity elements of the group, and the output is connected to the first input of the code generation block whose outputs are connected to the inputs of the group of the display unit and are the outputs of the second group of the device, and the output of the code forming unit is connected to the second input of the power cut-off unit, the control input of the register and is the second output device, the output of the control unit is connected to the first input of the control unit and is the first output of the device, the third input of the control unit is the third input of the device. 2. Device by π. 1, characterized in that the ananiz unit contains a comparator, the first trigger, the first element I, the load element and the voltage stabilization element, the anode of which is connected to the first input of the block, and the cathode is connected to the inverse input of the comparator, which is connected to the common bus of the block through the load element , the direct input of the comparator is connected to the common bus of the block, the output of the comparator is connected to the reset input of the first trigger 5 C P 77832 1 177832 Hera, sync; which and the first input of the first element And are the second input of the block, the output of the first trigger is connected to the second input of the first element And, the output of which is the output of the block. 3, Device by π. 1, characterized in that the code generation unit contains a second trigger, a second element AND and a counter, the reset input of the second trigger is the first input of the block, the installation input of the second trigger and the reset input of the counter are the second input of the block, the information input of the second trigger is connected to the common bus of the block and the synchronous input - with the last output of the counter, the outputs of the counter are the outputs of the group of the block, and the counting input is connected to the output of the second element And, the first input of which is the third input of the block, the output of the second trigger is connected to torym input of the second AND gate is the output unit. 4. Device by π. 1, that is, in that the control unit contains the third and fourth triggers, the synchronous input of the third trigger is the first input of the unit, and the installation input is the third input of the unit, the synchronous input of the fourth trigger is the second input of the unit, the output of the third trigger is connected to the information input the fourth flip-flop is the first output of the block, the output of the fourth flip-flop is connected to the reset input of the third flip-flop and is the second output of the block. I