CN201937240U - Overheating protection circuit for printer - Google Patents
Overheating protection circuit for printer Download PDFInfo
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- CN201937240U CN201937240U CN 201120039185 CN201120039185U CN201937240U CN 201937240 U CN201937240 U CN 201937240U CN 201120039185 CN201120039185 CN 201120039185 CN 201120039185 U CN201120039185 U CN 201120039185U CN 201937240 U CN201937240 U CN 201937240U
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Abstract
The utility model relates to an overheating protection circuit for a printer, which comprises a reference circuit module for outputting a reference value, an overheating protection reference circuit for outputting an overheating reference value, and a first comparison circuit for outputting switch signals of the printer according to the reference value and the overheating reference value, wherein the reference circuit module is connected with the first input end of the first comparison circuit; the overheating protection reference circuit is connected with the second input end of the first comparison circuit; and the overheating protection reference circuit comprises a thermistor RT1 for changing the overheating reference value according to the temperature of the printer. In the utility model, a hardware independent from a software detection and protection unit is adopted for dual overheating protection of the printer, so that the overheating protection of the thermal printer is more reliable.
Description
Technical field
The utility model relates to the printer applications field, more particularly, relates to a kind of printer overheating protection circuit.
Background technology
As everyone knows, printer is a kind of common used in industry equipment, and it need guarantee higher reliability.In the prior art, the host CPU of printer is by sampling to thermosensitive resistance, thereby judges that by software Current Temperatures opens or close printer power supply, thereby realizes the overtemperature protection to printer.Because there is certain unpredictability in software processes; may cause program exception or deadlock when particularly digital circuit is interfered; overheat protective function forfeiture this moment can't be cut off the power supply of printer, apparatus overheat will occur, smolder or catastrophic consequence such as on fire.
The utility model content
The technical problems to be solved in the utility model is; thereby be subject to disturb the defective of forfeiture overheat protective function at the printer overheating protection circuit of prior art; a kind of printer overheating protection circuit of hardware is provided; be independent of the software detection protected location, make that the overtemperature protection of thermal printer is more reliable.
The technical scheme that its technical problem that solves the utility model adopts is: construct a kind of printer overheating protection circuit; reference circuit module comprising the output comparison reference; export the overtemperature protection reference circuit of overheated reference value and according to first comparison circuit of described comparison reference and described overheated reference value output printer switching signal; described reference circuit module is connected with the first input end of described first comparison circuit; described overtemperature protection reference circuit is connected with second input of described first comparison circuit, and described overtemperature protection reference circuit comprises the thermistor RT1 according to the described overheated reference value of printer temperature change.
In printer overheating protection circuit described in the utility model, described reference circuit module comprises first reference circuit of exporting described comparison reference and second reference circuit that changes described comparison reference.
In printer overheating protection circuit described in the utility model; described second reference circuit comprises second comparison circuit and resistance R 4; second input of described second comparison circuit connects reference voltage; the first input end of described second comparison circuit is connected with the output of described first comparison circuit; the first input end of described second comparison circuit is connected with power supply VCC by resistance R 5 simultaneously, and the output of described second comparison circuit is connected with the first input end of described first comparison circuit by resistance R 4.
In printer overheating protection circuit described in the utility model; described first reference circuit comprises resistance R 2 and resistance R 3; described resistance R 2 one ends are connected with power supply VCC; the other end is connected with an end of described resistance R 3, the first input end of described first comparison circuit respectively, the other end ground connection of described resistance R 3.
In printer overheating protection circuit described in the utility model; described overtemperature protection reference circuit also comprises resistance R 1; described resistance R 1 one ends are connected with power supply VCC; the other end is connected with the end of described thermistor RT1, second input of described first comparison circuit respectively; the other end ground connection of described thermistor RT1; the first input end of described first comparison circuit and described second comparison circuit is reverse input end, and second input of described first comparison circuit and described second comparison circuit is positive input.
In printer overheating protection circuit described in the utility model; described overtemperature protection reference circuit also comprises resistance R 1; described resistance R 1 one end ground connection; the other end is connected with the end of described thermistor RT1, second input of described first comparison circuit respectively; the other end of described thermistor RT1 is connected with power supply VCC; the first input end of described first comparison circuit and described second comparison circuit is positive input, and second input of described first comparison circuit and described second comparison circuit is reverse input end.
In printer overheating protection circuit described in the utility model, described first comparison circuit and the described second comparison circuit compositing chip U1.
In printer overheating protection circuit described in the utility model, described printer overheating protection circuit also comprises sampling unit that the resistance value of described thermistor RT1 is sampled, calculates the computing unit of described printer temperature and according to the switch element of result of calculation output printer switching signal according to sampled result.
The utility model is also constructed a kind of printer overheating protection circuit, comprising the overtemperature protection reference circuit of the reference circuit module of output comparison reference, the overheated reference value of output and according to first comparison circuit of described comparison reference and described overheated reference value output printer switching signal;
Described reference circuit module comprises first reference circuit of exporting described comparison reference and second reference circuit that changes described comparison reference, and described reference circuit module is connected with the first input end of described first comparison circuit;
Described overtemperature protection reference circuit comprises resistance R 1 and according to the thermistor RT1 of the described overheated reference value of printer temperature change, described resistance R 1 one ends are connected with power supply VCC, the other end is connected with the end of described thermistor RT1, second input of described first comparison circuit respectively, the other end ground connection of described thermistor RT1;
Described first reference circuit comprises resistance R 2 and resistance R 3, and described resistance R 2 one ends are connected with power supply VCC, and the other end is connected with an end of described resistance R 3, the first input end of described first comparison circuit respectively, the other end ground connection of described resistance R 3;
Described second reference circuit comprises second comparison circuit and resistance R 4, second input of described second comparison circuit connects reference voltage, the first input end of described second comparison circuit is connected with the output of described first comparison circuit, the first input end of described second comparison circuit is connected with power supply VCC by resistance R 5 simultaneously, and the output of described second comparison circuit is connected with the first input end of described first comparison circuit by resistance R 4;
The first input end of described first comparison circuit and described second comparison circuit is reverse input end, and second input of described first comparison circuit and described second comparison circuit is positive input;
Described first comparison circuit and the described second comparison circuit compositing chip U1.
The utility model is also constructed a kind of printer overheating protection circuit, comprising the overtemperature protection reference circuit of the reference circuit module of output comparison reference, the overheated reference value of output and according to first comparison circuit of described comparison reference and described overheated reference value output printer switching signal;
Described reference circuit module comprises first reference circuit of exporting described comparison reference and second reference circuit that changes described comparison reference, and described reference circuit module is connected with the first input end of described first comparison circuit;
Described overtemperature protection reference circuit comprises resistance R 1 and according to the thermistor RT1 of the described overheated reference value of printer temperature change, described resistance R 1 one end ground connection, the other end is connected with the end of described thermistor RT1, second input of described first comparison circuit respectively, and the other end of described thermistor RT1 is connected with power supply VCC;
Described first reference circuit comprises resistance R 2 and resistance R 3, and described resistance R 2 one ends are connected with power supply VCC, and the other end is connected with an end of described resistance R 3, the first input end of described first comparison circuit respectively, the other end ground connection of described resistance R 3;
Described second reference circuit comprises second comparison circuit and resistance R 4, second input of described second comparison circuit connects reference voltage, the first input end of described second comparison circuit is connected with the output of described first comparison circuit, the first input end of described second comparison circuit is connected with power supply VCC by resistance R 5 simultaneously, and the output of described second comparison circuit is connected with the first input end of described first comparison circuit by resistance R 4;
The first input end of described first comparison circuit and described second comparison circuit is positive input, and second input of described first comparison circuit and described second comparison circuit is reverse input end;
Described first comparison circuit and the described second comparison circuit compositing chip U1.
Implement printer overheating protection circuit of the present utility model, have following beneficial effect: adopt to be independent of of the dual overtemperature protection of the hardware of software detection protected location, make that the overtemperature protection of thermal printer is more reliable as printer.
The overheating protection circuit that is arranged so that of second reference circuit can better be realized the startup and the releasing of overtemperature protection according to variation of temperature.The overtemperature protection reference circuit has multiple implementation method and selects for the user.First comparison circuit and second comparison circuit are integrated to make that being provided with of overheating protection circuit is convenient.The software detection protection makes overtemperature protection more reliable.
Description of drawings
The utility model is described in further detail below in conjunction with drawings and Examples, in the accompanying drawing:
Fig. 1 is the structural representation of first preferred embodiment of printer overheating protection circuit of the present utility model;
Fig. 2 is the structural representation of second preferred embodiment of printer overheating protection circuit of the present utility model;
Fig. 3 is the circuit diagram of first preferred embodiment of printer overheating protection circuit of the present utility model;
Fig. 4 is the circuit diagram of second preferred embodiment of printer overheating protection circuit of the present utility model;
Fig. 5 is the circuit diagram of the 3rd preferred embodiment of printer overheating protection circuit of the present utility model.
Embodiment
Below in conjunction with diagram, preferred embodiment of the present utility model is described in detail.
At Fig. 1; in the schematic diagram of the preferred embodiment of the printer overheating protection circuit of the present utility model shown in 3; described printer overheating protection circuit comprises reference circuit module 1; the overtemperature protection reference circuit 2 and first comparison circuit 3; reference circuit module 1 is used to export comparison reference; overtemperature protection reference circuit 2 is used to export overheated reference value; first comparison circuit 3 is used for according to comparison reference and overheated reference value output printer switching signal; reference circuit module 1 is connected with the first input end of first comparison circuit 3; overtemperature protection reference circuit 2 is connected with second input of first comparison circuit 3; overtemperature protection reference circuit 2 comprises thermistor RT1, and thermistor RT1 is used for according to the overheated reference value of printer temperature change.When adopting printer overheating protection circuit of the present utility model; send comparison reference by reference circuit module 1; send overheated reference value by overtemperature protection reference circuit 2; first comparison circuit, 3 pairs of comparisons reference value and overheated reference value compare; because thermistor RT1 can be according to the overheated reference value of printer temperature change; therefore when the printer temperature is too high; send the shutdown signal of printer by the comparative result of first comparison circuit 3; send the start signal of printer again by the time-delay of software temperature detection or timer again, realize the automatic overtemperature protection of thermal printer and recovery automatically.Employing is independent of the dual overtemperature protection of the hardware of software detection protected location as printer, makes that the overtemperature protection of thermal printer is more reliable.
In the structural representation of second preferred embodiment of printer overheating protection circuit of the present utility model shown in Figure 2; reference circuit module 1 comprises first reference circuit 11 and second reference circuit 12; first reference circuit 11 is used to export described comparison reference, and second reference circuit 12 is used to change described comparison reference.The comparison reference that is provided with as first reference circuit 11 is 5V, when having served as hot reference value greater than 5V, first comparison circuit 3 can send the shutdown signal of printer and cut out printer, at this moment second reference circuit 12 can be changed into 4V with comparison reference, when only having served as hot reference value less than 4V, first comparison circuit 3 sends the start signal open printing machine of printer, and at this moment first comparison circuit 3 can become comparison reference again 5V again.The overheating protection circuit that is arranged so that of second reference circuit 12 can better be realized the startup and the releasing of overtemperature protection according to variation of temperature, can not cause the frequent open and close of printer.
In the circuit diagram of second preferred embodiment of printer overheating protection circuit of the present utility model shown in Figure 4; second reference circuit 12 comprises second comparison circuit 121 and resistance R 4; second input of second comparison circuit 121 connects reference voltage, and (the generation circuit of reference voltage comprises resistance R 6; resistance R 7 and power supply VCC); the first input end of second comparison circuit 121 is connected with the output of first comparison circuit 3; the first input end of second comparison circuit 121 is connected with power supply VCC by resistance R 5 simultaneously, and the output of second comparison circuit 121 is connected with the first input end of first comparison circuit 3 by resistance R 4.Second reference circuit 12 changes comparison reference by the output valve of first comparison circuit 3, thus end ground connection or the unsettled variation that causes comparison reference that the output valve of first comparison circuit 3 can cause resistance R 4 to be connected with second comparison circuit 121.Like this when resistance R 4 ground connection; the sampled voltage of the first input end of first comparison circuit 3 is VCC*[R3*R4/ (R3+R4)]/[R2+R3*R4/ (R3+R4)]; when resistance R 4 is unsettled; the sampled voltage of the first input end of first comparison circuit 3 is VCC*R3/ (R2+R3), and the sampled voltage when unsettled is provided with first comparison circuit 3 and overtemperature protection reference circuit 2 and reaches the automatic startup that realizes overtemperature protection and automatically terminate the sampled voltage during according to resistance R 4 ground connection less than resistance R 4.
In the circuit diagram of the preferred embodiment of the printer overheating protection circuit of the present utility model shown in Fig. 2-4; first reference circuit 11 comprises resistance R 2 and resistance R 3; resistance R 2 one ends are connected with power supply VCC; the other end is connected the other end ground connection of resistance R 3 with the first input end that an end of resistance R 3 is stated first comparison circuit 3 respectively.First reference circuit 11 the initial value that has guaranteed comparison reference is set, also can adopt other bleeder circuit to realize the function of same sampling comparison reference certainly.
Circuit diagram at second preferred embodiment of printer overheating protection circuit of the present utility model shown in Figure 4; Overtemperature protection reference circuit 2 also comprises resistance R 1; resistance R 1 one ends are connected with power supply VCC; the other end is connected with the end of thermistor RT1, second input of first comparison circuit 3 respectively; the other end ground connection of thermistor RT1; the first input end of first comparison circuit 3 and second comparison circuit 121 is reverse input end, and second input of first comparison circuit 3 and second comparison circuit 121 is positive input.During the work of this printer overheating protection circuit; when the temperature of printer is hanged down; the resistance value of thermistor RT1 is higher; cause the comparison reference of the overheated reference value of overtemperature protection reference circuit 2 outputs greater than 1 output of reference circuit module; first comparison circuit, 3 output high level; at this moment because the output of first comparison circuit 3 is connected to second input of second comparison circuit 121; at this moment the output voltage of second input of second comparison circuit 121 is higher than the output voltage of the first input end of second comparison circuit 121; cause the output of second comparison circuit, 121 low levels; resistance R 4 is equivalent to ground connection; the comparison reference of the first input end of first comparison circuit 3 is VCC*[R3*R4/ (R3+R4)]/[R2+R3*R4/ (R3+R4)]; at this moment because first comparison circuit 3 is exported high level, printer can operate as normal.When the temperature of printer is higher; the resistance value step-down of thermistor RT1; cause the overheated reference value of overtemperature protection reference circuit 2 outputs to descend; when the overheated reference value of overheated protection reference circuit 2 outputs during less than the comparison reference of reference circuit module 1 output; first comparison circuit 3 reverses; first comparison circuit, 3 output low levels; at this moment the output voltage of second input of second comparison circuit 121 is lower than the output voltage of second comparison circuit, 121 first input ends; cause the output of second comparison circuit, 121 high level; resistance R 4 is equivalent to unsettled; at this moment because first comparison circuit, 3 output low levels; printer quits work; while is owing to resistance R 4 is unsettled; the comparison reference of first input end that causes first comparison circuit 3 is by VCC*[R3*R4/ (R3+R4)]/[R2+R3*R4/ (R3+R4)] increase and be VCC*R3/ (R2+R3); have only temperature to reduce when printer; the resistance value of thermistor RT1 uprises once more; and make the overheated reference value of overtemperature protection reference circuit 2 output greater than VCC*R3/ (R2+R3); at this moment first comparison circuit 3 just can be exported high level; the printer operate as normal, the comparison reference of the first input end of first comparison circuit 3 returns to VCC*[R3*R4/ (R3+R4) simultaneously]/[R2+R3*R4/ (R3+R4)].Because VCC*R3/ (R2+R3) must be greater than VCC*[R3*R4/ (R3+R4)]/[R2+R3*R4/ (R3+R4)], make when printer recovers operate as normal, guarantee that the temperature of printer is lower than the overtemperature protection temperature.
Circuit diagram at the 3rd preferred embodiment of printer overheating protection circuit of the present utility model shown in Figure 5; Overtemperature protection reference circuit 2 also comprises resistance R 1; resistance R 1 one end ground connection; the other end is connected with the end of thermistor RT1, second input of first comparison circuit 3 respectively; the other end of thermistor RT1 is connected with power supply VCC; the first input end of first comparison circuit 3 and second comparison circuit 121 is positive input, and second input of first comparison circuit 3 and second comparison circuit 121 is reverse input end.During the work of this printer overheating protection circuit; when the temperature of printer is hanged down; the resistance value of thermistor RT1 is higher; cause the overheated reference value of overtemperature protection reference circuit 2 outputs to be lower than the comparison reference that reference circuit module 1 is exported; first comparison circuit, 3 output high level; at this moment because the output of first comparison circuit 3 is connected to second input of second comparison circuit 121; at this moment the output voltage of second input of second comparison circuit 121 is higher than the output voltage of the first input end of second comparison circuit 121; cause the output of second comparison circuit, 121 high level; resistance R 4 is equivalent to unsettled; the comparison reference of the first input end of first comparison circuit 3 is VCC*R3/ (R2+R3); at this moment because first comparison circuit 3 is exported high level, printer can operate as normal.When the temperature of printer is higher; the resistance value step-down of thermistor RT1; cause the overheated reference value of overtemperature protection reference circuit 2 outputs to rise; when the overheated reference value of overheated protection reference circuit 2 outputs during greater than the comparison reference of reference circuit module 1 output; first comparison circuit 3 reverses; first comparison circuit, 3 output low levels; at this moment the output voltage of second input of second comparison circuit 121 is higher than the output voltage of second comparison circuit, 121 first input ends; cause the output of second comparison circuit, 121 low levels; resistance R 4 is equivalent to ground connection; at this moment because first comparison circuit, 3 output low levels; printer quits work; simultaneously because the ground connection of resistance R 4; cause the comparison reference of the first input end of first comparison circuit 3 to be reduced to VCC*[R3*R4/ (R3+R4) by VCC*R3/ (R2+R3)]/[R2+R3*R4/ (R3+R4)]; have only temperature to reduce when printer; the resistance value of thermistor RT1 uprises once more; and make that the overheated reference value of overtemperature protection reference circuit 2 output is less than VCC*[R3*R4/ (R3+R4)]/[R2+R3*R4/ (R3+R4)]; at this moment first comparison circuit 3 just can be exported high level; the printer operate as normal, the comparison reference of the first input end of first comparison circuit 3 returns to VCC*R3/ (R2+R3) simultaneously.Because VCC*[R3*R4/ (R3+R4)]/[R2+R3*R4/ (R3+R4)] must be less than VCC*R3/ (R2+R3), and in the time of making printer recovery operate as normal, the temperature of assurance printer is lower than the overtemperature protection temperature.
Circuit diagram at the preferred embodiment of the printer overheating protection circuit of the present utility model shown in Fig. 4,5; First comparison circuit 3 and second comparison circuit, 121 compositing chip U1.Chip U1 has used LM393, and is reasonable in design with low cost, helps producing in enormous quantities.First comparison circuit 3 and second comparison circuit 121 is integrated makes that being provided with of overheating protection circuit is convenient.
Preferred embodiment as printer overheating protection circuit of the present utility model; described printer overheating protection circuit also comprises sampling unit, computing unit and switch element; sampling unit is used for the resistance value of described thermistor RT1 is sampled; computing unit is used for calculating described printer temperature according to sampled result, and switch element is used for according to result of calculation output printer switching signal.The software detection protection of forming by sampling unit, computing unit and switch element makes that the overtemperature protection of printer is more reliable.
The utility model also relates to a kind of printer overheating protection circuit, comprising the overtemperature protection reference circuit 2 of the reference circuit module 1 of output reference value, the overheated reference value of output and according to first comparison circuit 3 of described comparison reference and described overheated reference value output printer switching signal; Described reference circuit module 1 comprises first reference circuit 11 of exporting described comparison reference and second reference circuit 12 that changes described comparison reference, and described reference circuit module 1 is connected with the first input end of described first comparison circuit 3; Described overtemperature protection reference circuit 2 comprises resistance R 1 and according to the thermistor RT1 of the described overheated reference value of printer temperature change, described resistance R 1 one ends are connected with power supply VCC, the other end is connected the other end ground connection of described thermistor RT1 with the end of described thermistor RT1, second input of described first comparison circuit 3 respectively; Described first reference circuit 11 comprises resistance R 2 and resistance R 3, and described resistance R 2 one ends are connected with power supply VCC, and the other end is connected with an end of described resistance R 3, the first input end of described first comparison circuit 3 respectively, the other end ground connection of described resistance R 3; Described second reference circuit 12 comprises second comparison circuit 121 and resistance R 4, second input of described second comparison circuit 121 connects reference voltage, the first input end of described second comparison circuit 121 is connected with the output of described first comparison circuit 3, the first input end of described second comparison circuit 121 is connected with power supply VCC by resistance R 5 simultaneously, and the output of described second comparison circuit 121 is connected with the first input end of described first comparison circuit 3 by resistance R 4; The first input end of described first comparison circuit 3 and described second comparison circuit 121 is reverse input end, and second input of described first comparison circuit 3 and described second comparison circuit 121 is positive input; Described first comparison circuit 3 and described second comparison circuit, 121 compositing chip U1.Concrete execution mode is identical with above-mentioned specific embodiment with beneficial effect, specifically referring to the foregoing description.
The utility model also relates to a kind of printer overheating protection circuit, comprising the overtemperature protection reference circuit 2 of the reference circuit module 1 of output comparison reference, the overheated reference value of output and according to first comparison circuit 3 of described comparison reference and described overheated reference value output printer switching signal; Described reference circuit module 1 comprises first reference circuit 11 of exporting described comparison reference and second reference circuit 12 that changes described comparison reference, and described reference circuit module 1 is connected with the first input end of described first comparison circuit 3; Described overtemperature protection reference circuit 2 comprises resistance R 1 and according to the thermistor RT1 of the described overheated reference value of printer temperature change, described resistance R 1 one end ground connection, the other end is connected with the end of described thermistor RT1, second input of described first comparison circuit 3 respectively, and the other end of described thermistor RT1 is connected with power supply VCC; Described first reference circuit 11 comprises resistance R 2 and resistance R 3, and described resistance R 2 one ends are connected with power supply VCC, and the other end is connected with an end of described resistance R 3, the first input end of described first comparison circuit 3 respectively, the other end ground connection of described resistance R 3; Described second reference circuit 12 comprises second comparison circuit 121 and resistance R 4, second input of described second comparison circuit 121 connects reference voltage, the first input end of described second comparison circuit 121 is connected with the output of described first comparison circuit 3, the first input end of described second comparison circuit 121 is connected with power supply VCC by resistance R 5 simultaneously, and the output of described second comparison circuit 121 is connected with the first input end of described first comparison circuit 3 by resistance R 4; The first input end of described first comparison circuit 3 and described second comparison circuit 121 is positive input, and second input of described first comparison circuit 3 and described second comparison circuit 121 is reverse input end; Described first comparison circuit 3 and described second comparison circuit, 121 compositing chip U1.Concrete execution mode is identical with above-mentioned specific embodiment with beneficial effect, specifically referring to the foregoing description.
The change in resistance of the thermistor RT1 that a comparable chip U1 detection of the utility model use printer carries; when the printer temperature raise and thermistor RT1 resistance is lower than/when being higher than set point; circuit output low level signal at stop printer power supply; have only the printer temperature to reduce and the resistance of thermistor RT1 is higher than/when being lower than set point; circuit just can be exported high level signal and reopen printer power supply, thereby realizes the more reliable overtemperature protection of thermal printer.The utility model adopts hardware circuit to realize the printer overtemperature protection, is the strong of simple software detection control replenished, and plays critical protective effect when software fault occurring.Improved the reliability of equipment greatly, the components and parts that this circuit of while relates to are device commonly used, and U1 has used LM393, and is reasonable in design with low cost, helps producing in enormous quantities.
The above only is embodiment of the present utility model; be not so limit claim of the present utility model; every equivalent structure transformation that utilizes the utility model specification and accompanying drawing content to be done; or directly or indirectly be used in other relevant technical fields, all in like manner be included in the scope of patent protection of the present utility model.
Claims (10)
1. printer overheating protection circuit; it is characterized in that; comprise the reference circuit module (1) of exporting comparison reference; export the overtemperature protection reference circuit (2) of overheated reference value and according to first comparison circuit (3) of described comparison reference and described overheated reference value output printer switching signal; described reference circuit module (1) is connected with the first input end of described first comparison circuit (3); described overtemperature protection reference circuit (2) is connected with second input of described first comparison circuit (3), and described overtemperature protection reference circuit (2) comprises the thermistor RT1 according to the described overheated reference value of printer temperature change.
2. printer overheating protection circuit according to claim 1 is characterized in that, described reference circuit module (1) comprises first reference circuit (11) of exporting described comparison reference and second reference circuit (12) that changes described comparison reference.
3. printer overheating protection circuit according to claim 2; it is characterized in that; described second reference circuit (12) comprises second comparison circuit (121) and resistance R 4; second input of described second comparison circuit (121) connects reference voltage; the first input end of described second comparison circuit (121) is connected with the output of described first comparison circuit (3); the first input end of described second comparison circuit (121) is connected with power supply VCC by resistance R 5 simultaneously, and the output of described second comparison circuit (121) is connected with the first input end of described first comparison circuit (3) by resistance R 4.
4. according to arbitrary described printer overheating protection circuit in the claim 1 to 3; it is characterized in that; described first reference circuit (11) comprises resistance R 2 and resistance R 3; described resistance R 2 one ends are connected with power supply VCC; the other end is connected the other end ground connection of described resistance R 3 with an end of described resistance R 3, the first input end of described first comparison circuit (3) respectively.
5. printer overheating protection circuit according to claim 4; it is characterized in that; described overtemperature protection reference circuit (2) also comprises resistance R 1; described resistance R 1 one ends are connected with power supply VCC; the other end respectively with the end of described thermistor RT1; second input of described first comparison circuit (3) connects; the other end ground connection of described thermistor RT1; the first input end of described first comparison circuit (3) and described second comparison circuit (121) is reverse input end, and second input of described first comparison circuit (3) and described second comparison circuit (121) is positive input.
6. printer overheating protection circuit according to claim 4; it is characterized in that; described overtemperature protection reference circuit (2) also comprises resistance R 1; described resistance R 1 one end ground connection; the other end respectively with the end of described thermistor RT1; second input of described first comparison circuit (3) connects; the other end of described thermistor RT1 is connected with power supply VCC; the first input end of described first comparison circuit (3) and described second comparison circuit (121) is positive input, and second input of described first comparison circuit (3) and described second comparison circuit (121) is reverse input end.
7. printer overheating protection circuit according to claim 1 is characterized in that, described first comparison circuit (3) and described second comparison circuit (121) compositing chip U1.
8. printer overheating protection circuit according to claim 1; it is characterized in that described printer overheating protection circuit also comprises sampling unit that the resistance value of described thermistor RT1 is sampled, calculates the computing unit of described printer temperature and according to the switch element of result of calculation output printer switching signal according to sampled result.
9. printer overheating protection circuit, it is characterized in that, comprise the overtemperature protection reference circuit (2) of the reference circuit module (1) of exporting reference value, the overheated reference value of output and according to first comparison circuit (3) of described comparison reference and described overheated reference value output printer switching signal;
Described reference circuit module (1) comprises first reference circuit (11) of exporting described comparison reference and second reference circuit (12) that changes described comparison reference, and described reference circuit module (1) is connected with the first input end of described first comparison circuit (3);
Described overtemperature protection reference circuit (2) comprises resistance R 1 and according to the thermistor RT1 of the described overheated reference value of printer temperature change, described resistance R 1 one ends are connected with power supply VCC, the other end is connected the other end ground connection of described thermistor RT1 with the end of described thermistor RT1, second input of described first comparison circuit (3) respectively;
Described first reference circuit (11) comprises resistance R 2 and resistance R 3, and described resistance R 2 one ends are connected with power supply VCC, and the other end is connected the other end ground connection of described resistance R 3 with an end of described resistance R 3, the first input end of described first comparison circuit (3) respectively;
Described second reference circuit (12) comprises second comparison circuit (121) and resistance R 4, second input of described second comparison circuit (121) connects reference voltage, the first input end of described second comparison circuit (121) is connected with the output of described first comparison circuit (3), the first input end of described second comparison circuit (121) is connected with power supply VCC by resistance R 5 simultaneously, and the output of described second comparison circuit (121) is connected with the first input end of described first comparison circuit (3) by resistance R 4;
The first input end of described first comparison circuit (3) and described second comparison circuit (121) is reverse input end, and second input of described first comparison circuit (3) and described second comparison circuit (121) is positive input;
Described first comparison circuit (3) and described second comparison circuit (121) compositing chip U1.
10. printer overheating protection circuit, it is characterized in that, comprise the overtemperature protection reference circuit (2) of the reference circuit module (1) of exporting comparison reference, the overheated reference value of output and according to first comparison circuit (3) of described comparison reference and described overheated reference value output printer switching signal;
Described reference circuit module (1) comprises first reference circuit (11) of exporting described comparison reference and second reference circuit (12) that changes described comparison reference, and described reference circuit module (1) is connected with the first input end of described first comparison circuit (3);
Described overtemperature protection reference circuit (2) comprises resistance R 1 and according to the thermistor RT1 of the described overheated reference value of printer temperature change, described resistance R 1 one end ground connection, the other end is connected with the end of described thermistor RT1, second input of described first comparison circuit (3) respectively, and the other end of described thermistor RT1 is connected with power supply VCC;
Described first reference circuit (11) comprises resistance R 2 and resistance R 3, and described resistance R 2 one ends are connected with power supply VCC, and the other end is connected the other end ground connection of described resistance R 3 with an end of described resistance R 3, the first input end of described first comparison circuit (3) respectively;
Described second reference circuit (12) comprises second comparison circuit (121) and resistance R 4, second input of described second comparison circuit (121) connects reference voltage, the first input end of described second comparison circuit (121) is connected with the output of described first comparison circuit (3), the first input end of described second comparison circuit (121) is connected with power supply VCC by resistance R 5 simultaneously, and the output of described second comparison circuit (121) is connected with the first input end of described first comparison circuit (3) by resistance R 4;
The first input end of described first comparison circuit (3) and described second comparison circuit (121) is positive input, and second input of described first comparison circuit (3) and described second comparison circuit (121) is reverse input end;
Described first comparison circuit (3) and described second comparison circuit (121) compositing chip U1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201120039185 CN201937240U (en) | 2011-02-15 | 2011-02-15 | Overheating protection circuit for printer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201120039185 CN201937240U (en) | 2011-02-15 | 2011-02-15 | Overheating protection circuit for printer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201937240U true CN201937240U (en) | 2011-08-17 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201120039185 Expired - Lifetime CN201937240U (en) | 2011-02-15 | 2011-02-15 | Overheating protection circuit for printer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201937240U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103323134A (en) * | 2013-06-13 | 2013-09-25 | 成都联腾动力控制技术有限公司 | Motor controller overheating judging circuit |
| CN103738057A (en) * | 2013-12-20 | 2014-04-23 | 深圳市新国都技术股份有限公司 | Hardware protective circuit used for temperature-sensitive printer |
| CN103818123A (en) * | 2012-05-02 | 2014-05-28 | 青岛海信智能商用***有限公司 | Power supply circuit of portable thermosensitive printer |
-
2011
- 2011-02-15 CN CN 201120039185 patent/CN201937240U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103818123A (en) * | 2012-05-02 | 2014-05-28 | 青岛海信智能商用***有限公司 | Power supply circuit of portable thermosensitive printer |
| CN103323134A (en) * | 2013-06-13 | 2013-09-25 | 成都联腾动力控制技术有限公司 | Motor controller overheating judging circuit |
| CN103738057A (en) * | 2013-12-20 | 2014-04-23 | 深圳市新国都技术股份有限公司 | Hardware protective circuit used for temperature-sensitive printer |
| CN103738057B (en) * | 2013-12-20 | 2015-11-18 | 深圳市新国都技术股份有限公司 | A kind of hardware protection circuit for thermal printer |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20110817 |