JPS6064762A - Administrating meter for electric soldering iron - Google Patents

Abstract

PURPOSE:To provide a titled small-sized administrating meter which performs easy operation administration with a single indicating meter by pressing a sensing part to an electric soldering iron, measuring temp. and knowing the insulation resistance value and leakage current value of the electric iron with an AC-DC converter and a logarithmic converter circuit. CONSTITUTION:A sensing part P having a thermocouple TC and a temp. compensating circuit RTC is pressed to an electric soldering iron SI heatd by a commercial AC power source. Levers l1, l2 are connected to terminals t1, t2 and the temp. is measured from the temp. graduation of a DC ammeter M. The levers l1, l2, l3, l4 are connected to terminals t3, t4, t5 and t6 to feed the logarithmic value detected with an AC-DC converter and logarithmic converter operating on DC power source +V, -V by a transformer T and IC1 to the ammeter M so that the insulation resistance value and leakage current value of the iron SI are known in the state of chassis grounding by t5, t6. The condition of the iron SI is detected by simply changing over the levers of the small-sized tester and the operation on site is easily administered.

Description

[Detailed Description of the Invention] (Purpose of the Invention) The present invention is intended to accurately control the insulation properties of electric soldering irons and the temperature of the tip of the soldering iron, which are very important in the soldering work of IC and other electronic circuit element wiring. The purpose of the present invention is to provide a measurement method that can be easily performed.

It goes without saying that soldering is an important work element in the manufacture of electronic R-devices, particularly in the wiring of ICs and other minute semiconductor circuit elements.

In order to prevent damage to circuit elements and functional deterioration due to soldering work, electric soldering irons used for such precision soldering work must be kept under strict insulation between the heater circuit and the iron tip.

In order to meet these demands, JI electric soldering iron
The S standard was established as JIS-C-9211 in 1955, and it stipulates that the insulation resistance value must be measured with a 500V 100MΩ megger and must be at least IOMΩ for A class irons and at least IMΩ for class 0 irons. According to the regulations, class A edges should be used for soldering work on precision electronic circuit components such as those mentioned above.

By the way, electric soldering irons are generally used for commercial AC, i.e. 1
The power source is 00V, 50 or 60Hz AC, and there is naturally a capacitance between the heater and the iron light. In addition, leakage current becomes a problem during work at the heating station of the iron tip. On the other hand, the above-mentioned standard certification is conducted using a megger, and therefore, it is measured using DC as a power source when it is cold, so it must be said that it is far removed from the actual use of electric soldering irons. For example, FIG. 3 shows A+ as measured by the inventors.
IIIC! 04 types (C is mica wire-wound type, A, B,
D is ceramic type) A class soldering iron, 500V
The actual insulation resistance measured using a 1000 MΩ megger (dotted line) and the actual measured value (solid line) of the same specimen using commercial AC as the power source are shown, but the measurement using the megger shows that the insulation resistance is excellent. Even if it is determined that there is an AC leakage current in actual use, it is found that there is an AC leakage current that is 2 to 10 times the value measured by a megger. However, in the megger measurement, the power to the soldering iron to be tested was momentarily cut off.

In addition, the specimen is a new product that was purchased directly from the manufacturer. The specimen in Figure 4 is a type of ceramic soldering iron, and it is natural that the performance of the latter would be inferior when measurements were started from new (at the beginning of use) and when measurements were started after 80 hours of use. Even if there is, the measurement value is measured by means of an IC, and AC is used as the measurement power source.
It can be seen that there is an order of magnitude difference between the C-association measurement values and the characteristics of changes over time. Note that the measurement method is the same as in the case of FIG. 3.

As can be seen from the above, it is important to avoid placing too much faith in the specifications displayed when purchasing a soldering iron, and it is also important to note that soldering irons do not perform well on the street if solder is knocked off or dropped on the floor during work. Because of this, constant management of insulation and temperature performance is necessary. To manage the insulation, there is also a measuring method using the above-mentioned method. 5. It is very troublesome to connect the wires each time during heating, and 1. As mentioned above, γI! U
＞j Nii [There is a problem with white's reliability. Connect a resistor between the part of the soldering iron that is being heated by supplying power and ground, and the voltage drop across the terminals of the resistor is 31 electrons: il' i! ! ! 1, it is possible to obtain leakage current or insulation resistance values that are close to the actual conditions of use, but in any case, it is difficult for factory JJ and factory L-11 to perform such troublesome management work on a daily basis. It's a place where you can't do it.

In addition, especially in the wiring of electronic circuit elements, inappropriate soldering tip temperature may lead to poor soldering to the soldering iron tip.
It is necessary to frequently check the temperature of the tip of a soldering iron while the iron is in use, as this may cause defective products. To date, there is still no measuring device that is convenient for frequently measuring the temperature of the tip of a soldering iron in the men's bath. Not offered selectively.

From the above point of view, the present inventors have studied and developed an electric soldering iron management device according to the present invention, and the present invention will be explained below with reference to embodiments shown in the drawings.

(Structure of the Invention) That is, the present invention includes a casing, a power supply device, a sensor device, an indicator device, an AC-DC conversion device, a logarithmic conversion device, and a changeover switch SW as described below.

Although the above-mentioned casing is not shown, it accommodates and fixes the following devices, and since each of these devices is extremely small, this casing is about the size of a normal radio tester. Manufactured.

The power supply device described above is an electric soldering iron S to be measured.
Through a rectifier connected to the secondary side of a power transformer T, which is plugged into a commercial AC power supply AC that is common to the power supply of L,
It supplies stable direct current to the required circuits, and in the illustrated embodiment, the rectified current is passed through the tracking regulator I.
It is supplied as 15V DC via C1.

The sensor device described above has a sensing section sp outside the housing.
A room temperature compensating circuit RTC made of a temperature variable resistor of purple sweet potato Cu is connected to one terminal of the thermocouple TC with the exposed part. In the illustrated example, the thermocouple TC conforms to JIS C-1602. The room temperature compensation circuit RTC is a balanced bridge circuit using a copper resistance of 10Ω at 0°C on one side and a fixed resistance of 10Ω on each other side, which electrically compensates for the influence of room temperature on the electromotive force of the thermocouple. It is for erasing.

The above-mentioned indicating device has a temperature display scale ranging from 0°C to 500°C, as shown in FIG.
An insulation resistance display scale that displays resistance values in the range of * to ■ on a megohm logarithmic scale, and a leakage current display scale that displays current values in the range of θ to 100 on a microampere logarithmic scale are displayed side by side on the board. Movable pointer on scale plate (not shown)
It consists of a DC ammeter M (see Figure 1).

As shown in the figure, the above-mentioned AC-DC conversion device has an addition operation amplifier circuit IC3 connected to the output circuit of a rectification operation amplifier circuit IC2, and in the illustrated example, between the input terminal t5 and the rectification operation amplifier circuit A protective resistor is inserted. In the illustrated example, R1=5001(Ω, R2-R3=R4=Ioo
There is Ω, R5:50, Ω, R6=10Kl”l.

The logarithmic conversion device described above is a circuit (encircled by a chain line) that is connected to the AC-DC conversion device and converts its output value into a logarithmic value, and this circuit in the illustrated example is often used as a discrete module UO amplifier. Are known. In the illustrated example, R7:l: 100KΩ, R8=6Ω.

In addition, in the illustrated example, the above-mentioned room temperature compensation circuit 1RT
Since the C, AC-DC converter, and the logarithmic converter 4 all require a DC supply, they are supplied with the DC output of 15V from the power supply device described above. In addition, in the illustrated example, the earth shaded with diagonal lines means the chassis earth or the earth busbar between the casings, and when using a metal casing, the withstand voltage is 4KV, 1ooo to protect the human body.
It is preferable to insert and connect a capacitor of about pF between the chassis ground and the casing.

Next, the changeover switch SW described above consists of a movable electrode having first and second switching positions and a fixed %M as described below. 11 + 12 + A3 + 4 are levers, and these levers are insulatively connected to each other and to a 1JIli11 knob (not shown) exposed outside the housing to form a movable electrode JM. . And Lepano l + 4. ! are each DC ammeter M
The levers are connected to one terminal of the sensor device, and the lever 14 is connected to the primary wiring of the tranos 1. ti + t2+ t31 t4+ t
5. t6 constitutes a fixed electrode, tl is one terminal of the above-mentioned sensor device, t2 is the other terminal, t3 is the output terminal of the above-mentioned logarithmic conversion device, and t4 is the output terminal of the above-mentioned AC-DC conversion device. The ground side input terminal, t5, is also a high voltage side input terminal, and t6 is a terminal connected to the chassis of the secondary coil of the power transformer T.

Among these terminals, t1+t3 are connected to the lever 11, t2
．． t4 is on lever 12, t5 is on lever h, and t6 is on lever! ! 4 respectively, while t3+t
4+t5 and i1+i2+t6 respectively correspond to the first switching position (the stone side in the figure) and the second switching position (left side) of the movable electrode.

According to the present invention, the tip of the electric soldering iron SI connected to the commercial AC power supply AC is brought into contact with the sensing part sp, and the movable electrode of the changeover switch SW is moved to the first switching position (
By switching to the second switching position (right side), the insulation resistance value and leakage current value of the soldering iron SI are displayed directly on the scale plate, and by switching the movable electrode of the changeover switch SW to the second switching position (left side), the soldering iron SI insulation resistance value and leakage current value are displayed directly on the scale plate. The previous temperature is displayed directly on the scale plate mentioned above.

That is, the present invention is constructed as described above, and in order to use this control device, the power supply device is plugged into a commercial AC power source AC, and the movable electrode of the changeover switch SW is set to the first changeover position using the above-mentioned knob. (right side). In this case, levers J, , J2 are each connected to terminal t3. t4, so that the direct current side M of the indicating device is connected to the input terminal t4 of the chassis-ground side of the AC-DC converter and the output terminal of the logarithmic converter, which is connected to the output terminal of the AC-DC converter. It is connected between the terminal t5 and the terminal t5. At the same time, the lever 13 connected to one terminal of the sensor device is connected to the high voltage side input terminal t5 of the AC-DC converter, and is connected to the primary side of the power transformer T of the electrically connected device. The lever 14 that is connected is connected to the chassis-grounded terminal t6 of the secondary coil of the power transformer T. Therefore, if the tip of the sample electric soldering iron SI connected to a commercial AC power supply AC touches the sensitive part SP of the thermocouple TC, the AC leakage current from the heater of the electric soldering iron SI to the tip will TC, inputted to the AC-DC conversion device described above through the lever, rectified by the rectifying operational amplifier circuit IC2, converted to an IT value by the addition operational amplifier circuit C3, and converted into a logarithmic value by the logarithmic conversion device. The withstand output is determined by the above A through Lepano 1, DC ammeter M and lever 4.
Flows to the chassis ground terminal t4 of the C-DC converter,
Next, pass the lever 4 through the chassis-grounded terminal t6 of the secondary coil of the power transformer T, and connect the commercial AC power supply AC.
, and the pointer on the scale plate of the indicating device directly indicates the leakage current value in logarithmic value.

That is, according to this control device, the sensitive part that touches the tip of the soldering iron is exposed from the housing, and as mentioned above, the knob of the changeover switch SW is moved to the first switching position side (right side) of the movable electrode. In the set state, all the circuits required to measure leakage current, including the ground circuit, are wired inside the housing, so connect the plug to the power supply and connect the tip of the electric soldering iron while it is heating up. Just by touching the sensing part, the leakage current value and the converted insulation resistance value can be directly read on the same scale as measuring 4 with a megger, and tl! There is no need for troublesome preparation work such as connecting the measuring device to the soldering iron for the measurement work. And, as a power source for measurement, the commercial AC power source itself, which is the cause of leakage current, is used as a power source for measurement, without using a separate power source that has nothing to do with leakage current. Since the leakage current tI is measured while the soldering iron is in use, the reliability of the displayed value is extremely high.

Next, when the knob of the changeover switch SW is switched to the second switching position of the movable electrode, the DC current phase M of the finger/J device passes through the levers 11 and 12, and the thermocouple of the sensor device A room temperature compensation circuit RTC is connected to both terminals of the thermocouple TC, and a room temperature compensation circuit RTC is connected to one terminal of the thermocouple TC.
, is connected, so that the actual soldering iron tip temperature in the operating state is directly displayed on the scale plate, regardless of the ambient temperature in which the soldering iron is used. In other words, by simply touching the tip of the electric soldering iron SI, which is being heated by the power supply, to the sensitive part of the sensor device, the actual state of use can be detected.
You can instantly know the temperature at the tip of one iron.

(Effects of the Invention) Thus, according to the present invention, it is possible to very quickly and easily measure the insulation resistance, which is essential for the management of electric soldering irons used in precision work, and the measured values can be measured in accordance with the actual usage. Close to reliable. In addition, by operating a single switch knob, you can instantly switch from insulation resistance measurement to iron tip temperature measurement, and the value can be read directly, so even if you repeat it many times at the soldering work site, there will be no hesitation, and therefore, the soldering work will be more reliable. While the performance is significantly improved, damage to the electronic circuit due to leakage current and uncertainty in soldering connections due to inappropriate iron tip temperature can be prevented, and as mentioned above, it can be used as a radio tester. Since it is easy to manufacture and convenient to handle, it greatly contributes to improving the productivity of equipment that requires precision soldering work, especially electronic equipment.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of an embodiment of the electric soldering iron control needle according to the present invention, Figure 2 is a front view of the scale plate, and Figures 3 and 4 are actually measured characteristics of the insulation resistance of the electric soldering iron. In the curve diagrams, Fig. 3 shows a comparison of four new products, and Fig. 4 shows a comparison of the same products, new and after long-term use. AC is a commercial alternating current power supply, T is a power transformer, Ic1 is a tracking regulator, sI is an electric soldering iron, T
C is a thermocouple, SP is a sensing part, RTC is a room temperature compensation circuit, M
is a DC ammeter, IC2 is a rectifying operation amplifier circuit, IC3 is an addition operation amplifier circuit, sw is a changeover switch, 11+12+13+4 is a lever, 11.12+13.14, 15, 16 are terminals, R]
, R2, R3゜1n4 + R5+ R6+ R7+
RB is a resistance. Patent applicant: Sanko Electric Meter Co., Ltd.

Claims (1)

[Claims] A casing that accommodates and fixes each of the following devices, and a casing that is connected to the secondary side of a power transformer T that is plugged into a commercial AC power supply that is common to the power source of the electric soldering iron SI to be measured. A power supply device supplies stable direct current to the required circuits through a rectifier, and a temperature-sensitive resistance element C is connected to one terminal of a thermocouple TC whose sensing part SP is exposed to the outside of the casing.
A sensor device connected to a room temperature compensation circuit RTC by U, a temperature display scale in the range of 0°C to 500°G, an insulation resistance display scale that displays resistance values in the range of 0 to ω on a megohm logarithmic scale, and 0 A DC current drawer with a movable pointer on a scale plate with a leakage current display scale displaying current values in the range of ~100 on a microampere logarithmic scale, and a rectifier operational amplifier circuit ■C2 Addition operation amplifier circuit I C3 is connected to the output circuit of A.
C, -DC conversion device; 8. A logarithmic conversion device connected to the AC-DC conversion device and having a circuit for converting the output value into a logarithmic value; and the following changeover switch Sw, wherein the changeover switch sw is It consists of a movable electrode with a first and a second switching position and a fixed electrode, the movable electrode being connected to a lever H1 of the sensor device which is connected respectively to one and the other terminal of the direct current side M. The lever 13 connected to one terminal and the lever 14 connected to the primary wiring of the power transformer T are insulatively connected to each other and to the movable knob exposed to the outside of the housing. The fixed electrode connects one terminal t1 of the sensor device and an output terminal t3 of the logarithmic conversion device to the lever 11.
, the other terminal t2 of the sensor device and the AC
- Connect the ground side hexagonal terminal t4 of the DC converter to the lever 12.
The high voltage side input terminal t of the AC-DC converter 4 is made to correspond to the lever 13, and the chassis-grounded end t6 of the secondary coil of the power transformer T is made to correspond to the lever J4, and the terminal t3+ t4+
t5+j6 are disposed so as to correspond to the first switching position of the movable electrode, and the terminals t1+t2 are disposed corresponding to the second switching position of the movable electrode, respectively, and the electric solder is connected to a commercial AC power source AC as a plug. Gote SI
By bringing the tip of the soldering iron into contact with the sensing part SP of the thermocouple and switching the movable electrode of the changeover switch SW to the first switching position, the insulation resistance value and leakage current value of the electric soldering iron SI can be adjusted. The electric soldering iron management meter is configured to directly display the temperature of each soldering iron tip of the electric soldering iron SI on the scale plate by switching the movable electrode of the changeover switch SW to the second switching position.