Engaged in electronic circuit design for so many years, do circuit experiment welding PCB board used too many chromium iron, summed up is nothing more than the use of ordinary single handle ferrochrome or constant temperature soldering station ferrochromium. The conclusion is that ordinary single-handle ferrochromium is cheap, but its life is really too short. The chromium iron head will not be used for a long time. The chromium iron head is also very oxidized. When welding, it often hangs tin. The welding time is too careless. The pads on the circuit board are also burned off. A handful of ferrochromium is sometimes scrapped in a few days. Later, the effect of welding with a constant temperature soldering station was greatly improved. First, the soldering temperature can be adjusted according to the size of the PCB pad, adjusted to a suitable temperature during soldering, and the soldered spot on the soldered board is even and bright; Secondly, because the ferrochrome head is constant temperature, some of the pads on the device need to repeatedly adjust the parameters to remove the welding several times without blanching the pads or the components being burned out, ensuring that the experimental work is carried out orderly; Thirdly, the life of the chrome iron head used at a constant temperature is many times longer than the life of a common ferrochrome head, which saves costs. More importantly, it does not affect the device due to welding problems or PCB damage during the experiment. As a result, the time and effort spent on solving artifacts are avoided. Using a constant temperature soldering station, I thought that other ferrochromes were toys or welding tools for non-electronic products. Although the soldering station is an ideal tool for electronics workers, it can sometimes be awkward to use. For example, when the work table is full of equipment, it is not easy to put a soldering station on a clean place, and for example, it is sometimes necessary. Take the ferrochromium out to repair a household electrical appliance machine or factory employees to go out and rework products, it is very inconvenient to carry, the most troublesome thing is that many products welding temperature SOP made clear requirements, but because of various reasons, employees do not operate according to the required temperature , resulting in unsatisfactory production process control... Recently, in a Hong Kong-owned oil plant contact business, we were fortunate to visit its production line and found that the GOOD933 ferrochrome used in its production line was attractive in appearance, simple in use, and comparable in function to a constant temperature soldering station. After consultation with related personnel, several trials of production lines were purchased and the results were good. In order to understand its technical characteristics, special analysis is as follows: First, appearance The materials used for the ferrochromium were observed to meet safety requirements. Second, function and characteristic This ferrochrome is a 220V single-handle in-line ferrochromium, which is powered by a three-core power plug. After testing, the chrome-iron head metal parts and the power plug are connected to the ground wire to ensure the safety of use. The yellow switch on the handle is a three-position thermostatic selector switch, which corresponds to 360 degrees, 390 degrees, and 420 degrees respectively. This is different from the constant temperature soldering station. (The temperature of the constant temperature soldering station is adjusted by a knob, and the dial Indicates the constant temperature setting value, but from the actual situation, 360 degrees is the most commonly used welding temperature, has met the need of most welding temperatures, if you feel the 360 ​​degree is not enough when welding large devices, optional 390 degrees or even 420 Welding. The small hole in the lower part of the yellow switch is a heating indicator lamp. The lamp is continuously flashing during use, indicating that the ferrochrome is in a constant temperature heating state. A small hole is used to correct the thermostatic temperature under the handle sheath near the indicator light. The chromium iron head and the chrome iron metal sheath are universally verified through comparison with the 900 Series, which are widely available on the market, and ensure the economical and simple replacement of parts. Third, the principle of constant temperature analysis In order to confirm that the ferrochrome does have the same thermostatic control function as the constant temperature soldering station and to understand its temperature control technology characteristics, we analyzed the control circuit board built in the handle and confirmed that the ferrochrome has a thermostatic control function. The principle is similar to the following figure. Let's make a general analysis. The temperature of the soldering iron control point is adjusted by using three different resistance resistors with three different switches to select and access the circuit. The temperature control accuracy is nominally ±3%, and the thermocouple is used. sensor. The control circuit adopts the alternating current mains direct step-down, filtering, steady voltage power supply scheme. Mains AC220V R1 step-down, D1 half-wave rectification, D2 clipping regulator, C1 filter as a comparison device IC power supply voltage and temperature setting voltage source. The IC-A3 pin is the thermocouple detection voltage input (corresponding to the temperature value); the 2 pin is the thermostat setting voltage. After the voltages at the two ends of the 3 and the 2 are compared, the pin 1 is output. The role of R5 is to feedback a small part of the input to the non-inverting input pin 3, so that the output lock is not changed when the small signal fluctuates. When the temperature detected by the thermocouple is low, the 3-pin level is lower than the 2-pin and the output 1-pin is also low. Further, the pin 6 of the IC-B amplifier is lowered relative to the fixedly-biased pin 5, and the output pin 7 is high. Since IC-B5 pin voltage is obtained by dividing AC220V by R6 and R7, the frequency and phase are completely the same as AC220V. Compared with 6-pin DC, AC voltage is output at pin 7. The AC voltage is reversed in parallel by C2, D4, D3 and D4 (acting with a bi-directional diode) to trigger the triac so that the corresponding voltage is applied to the heating wire of the soldering iron so as to achieve the purpose of constant temperature. In addition, some circuits have been analyzed to improve the temperature of the iron head and reduce the temperature overcharge circuit, because this is the manufacturer's patent technology, in order to avoid disputes, will not be detailed here. We have specifically tested the characteristics of this ferrochrome to confirm that the ferrochromium has stable performance, precise temperature control, rapid temperature recovery, and easy use. It is worthy of promotion and application. The last thing to mention is whether the employee selects the temperature according to the SOP requirements. Observe only the position of the yellow switch. 5.70mm Wire To Board Connectors 5.70mm Wire to Board,Wire To Board Connectors 5.70mm Wire to Board,Wire To Board Connectors ShenZhen Antenk Electronics Co,Ltd , https://www.pcbsocket.com