Temperature-rise self-control circuit of electric soldering iron

Technical Field

The invention relates to a self-controlled circuit temperature rise of the electric iron, which belongs to the technical field of electric power test.

Background Art

Electric iron, is circuit board is welded, an essential tool for testing, in cold climate or in winter when the power voltage is relatively low, the power supply of the electric soldering iron, as the temperature rising too slow and often inconvenient and, long waiting time, reducing the working efficiency, but also, energized electric iron, will consume a large amount of electric energy, waste of electric energy.

The content of the invention

The purpose of this invention is to overcome the plugging in the power supply of the electric iron, as the temperature rising too slow and often inconvenient and, long waiting time, reducing the working efficiency, the problem of waste of electrical energy. Electric soldering iron of the present invention the temperature self-control circuit, does not need manual operation, rapid temperature rise can be completed, to the iron reaches a certain temperature and then self-control to the normal heating state, thus brings convenience to users, the circuit is simple, it is easy to realize, energy-saving and environment-friendly, has good application prospect.

In order to achieve the above-mentioned goal, the invention adopts the following technical solutions:

An electric iron temperature self-control circuit, characterized in that includes a rectifier bridge VD, thermistor PTC and the electrolytic capacitor C1, the input end of the rectifier bridge VD external commercial power, the rectifier bridge is VD, connected in series between the negative output terminal of the thermistor PTC and the electrolytic capacitor C1, the electrolytic capacitor C1 is connected with the anode of the thermal resistor is connected with the PTC, the electrolytic capacitor C1 with the negative pole of the rectifier bridge is connected with the negative output end VD, the thermistor PTC also connected in parallel with a compensation resistor R1, the rectifier bridge is VD, is connected with the negative output end of the two ends of the irons the iron core of the electric iron.

The aforesaid an electric iron temperature self-control circuit, characterized in that said thermistor PTC resistance to demagnetization, the 18RM270, resistances to 18 subsidence.

The aforesaid an electric iron temperature self-control circuit, characterized in that the rectifier bridge VD to a high-voltage silicon stack rectifier bridge.

The aforesaid an electric iron temperature self-control circuit, characterized in that the compensation resistance R1 is the resistance value of the 1k subsidence.

The aforesaid an electric iron temperature self-control circuit, characterized in that the electrolytic capacitor C1 is the capacitance value 22uf, withstand voltage is 350 V.

The aforesaid an electric iron temperature self-control circuit, characterized in that at the input of the rectifier bridge is provided with a fuse VD F.

The beneficial results of this invention are: the electric soldering iron of the present invention the temperature self-control circuit, the output terminal of the rectifier bridge a thermistor from the electrolytic capacitor are connected in series to form the filtering circuit, through a thermal resistor in the electrolytic capacitor of the charge, discharge, because the internal resistance of the thermistor in the cold state is very small (approximately straight-through), the filtering efficiency of the electrolytic capacitor will reach the highest, the two ends of the output end of the rectifier bridge theoretical peak 314V voltage will be to the left and the right, in this power supply voltage, iron to rapid heating, there is no need to operate the, rapid temperature rise can be completed, to the iron reaches a certain temperature and then self-control to the normal heating state, thus brings convenience to users, the circuit is simple, it is easy to realize, energy-saving and environment-friendly, has good application prospect.

Description of drawings

Figure 1 is the wiring diagram of the invention commercial power power failure alarm circuit.

Mode of execution

With the binding specification below, further description of this invention. The following embodiment is used to more clearly illustrate the technical scheme of the invention, but not to limit the scope of protection of this invention.

As shown in Figure 1, an electric iron temperature self-control circuit, includes a rectifier bridge VD, thermistor PTC and the electrolytic capacitor C1, VD external commercial power input end of the rectifier bridge, the rectifier bridge is VD, connected in series between the negative output terminal of the thermistor PTC and the electrolytic capacitor C1, the electrolytic capacitor C1 is connected with the anode of the thermal resistor is connected with the PTC, the electrolytic capacitor C1 with the negative pole of the rectifier bridge is connected with the negative output end VD, the thermistor PTC also connected in parallel with a compensation resistor R1, the rectifier bridge is VD, is connected with the negative output end of the two ends of the irons the iron core of the electric iron.

The thermistor PTC resistance to demagnetization, the 18RM270, resistances to 18 the, high-voltage silicon stack of the rectifier bridge of the rectifier bridge to VD, the compensation resistor R1 is the resistance value of the 1k subsidence, electrolytic capacitor C1 is the capacitance value 22uf, withstand voltage is 350V, at the input of the rectifier bridge VD is provided with a fuse F, improving the reliability of the circuit.

The temperature of the electric iron of this invention the working principle of the automatic control circuit for, when the 220V commercial power by the rectifier bridge O. 9 × 220V = 198V VD a rectified pulsating DC voltage, the output of the rectifier bridge VD is connected with a thermistor PTC the two ends of the electrolytic capacitor C1 are connected in series to form the filter circuit, the electrolytic capacitor C1 to charge through the thermistor PTC, at the beginning of the discharge, at the beginning, because the internal resistance of the PTC thermistor in the cold state is very small 18 subsidence), so that the thermistor PTC from the electrolytic capacitor C1 of a filtering efficiency of the filter circuit will reach the highest, the voltage of the rectifier bridge VD will rise to the output end of the theoretical peak 220 * (square root of 2) = 314V the left and the right, in this power supply voltage, fast irons the iron core heating, rapid temperature rise after a certain period of time, because the electrolytic capacitor C1 charging, the discharge current will be the heat-sensitive resistance of PTC heating slowly, its internal resistance becomes large correspondingly, so that the charge-discharge time constant is increased, the filtering efficiency reduction directly, the voltage of two ends of the iron core to drop slowly to a certain degree and is kept constant, in order to prevent the thermistor after the internal resistance of the PTC is too large, the two ends of the load voltage drops too low, then the thermistor PTC connected in parallel on the two ends of a compensating resistor R1, thereby enabling constant stable irons the iron core after the power supply voltage of 220V, in order to maintain normal working state of the electric iron, does not need manual operation, rapid temperature rise can be completed, to the iron reaches a certain temperature and then self-control to the normal heating state, thus brings convenience to users, the circuit is simple, it is easy to realize, energy-saving and environment-friendly, has good application prospect.

The above shown and described the basic principle of this invention, the main characteristics and advantages. The industry technical personnel should understand, the invention is not subject to limitation of the above-mentioned embodiment, the above-mentioned embodiment and is described in the specification that only of the principles of the present invention, without deviating from the spirit and scope of the present invention under the condition of, the invention will also be with various changes and improvements, these changes and improvements fall into the claimed are within the scope of the present invention. The scope of the invention claimed by the attached claims define and its equivalent.