<> One , Composition of welding platform
It is generally supplied by the power supply , control circuit , Handle , Core heating , Composition of soldering iron head .
1, Handle ：
2, The soldering iron head is divided into heating core and soldering iron head , such as T12 The iron head ：
3, There are also separate heating core and soldering iron head ：
<> Two , White light of Chinese Cabbage T12 Soldering station
1, White light of Chinese Cabbage T12 Iron head
It's a heating core and a soldering iron head .
2, Then the iron head is equipped with a handle
The circuit in the handle has only two conductive shrapnel , When the soldering head is inserted , The two contact plates at the back end of the soldering iron head are connected with the spring piece in the handle , It is connected to the aviation plug at the back through the wire .
3,T12 Control panel
Two contact pieces on the soldering iron head pass through the wire , Then through the aviation plug , Aviation socket , Welded to the control panel T12 Negative and T12 positive electrode .
4, Power Supply
The negative pole and positive pole of the power supply on the control board need to be connected with a power supply . Power supply voltage input requirements ： direct 12V reach 24V( The best voltage is 24V), electric current 1.5A~3A.
This is it. T12 The whole process of self-made welding platform . Here's how it works , You may wonder how heating and measuring temperature are realized by only two wires from the soldering head .
It's very simple , Because there are two kinds of conductors on the iron head , This forms the thermocouple , And we know that thermocouples can measure temperature . Let's look at the formation conditions of thermocouples ：
When there are two different conductors or semiconductors A and B Form a loop , When the two ends are connected to each other , As long as the temperature at the two nodes is different , The temperature at one end is T, It is called working end or hot end , The temperature at the other end is T0
, It's called the free end （ Also known as the reference end ） Or cold end , An electromotive force will be generated in the circuit , The direction and size of the EMF are related to the material of the conductor and the temperature of the two contacts . This phenomenon is called “ Thermoelectric effect ”, The circuit consisting of two conductors is called “ Thermocouple ”, These two kinds of conductors are called “ Thermoelectric pole ”, The resulting electromotive force is called “ Thermoelectric EMF ”.
So at this moment, measure the temperature of the iron head , Found the temperature was low , Then electrify and heat the iron head , Heat for a while and disconnect , Measure the temperature of the soldering head again , Reheating ... Temperature measurement and heating are carried out alternately .
Look at the control panel below , There is an operational amplifier in the control to form a comparator , control MOS Tube switch . When the voltage on the thermocouple is greater than the reference voltage , Turn it off MOS Tube , Stop heating .
<> Three ,JBC Self made welding platform
JBC The soldering station is also integrated with the soldering head and the heating core , The difference is that JBC There are 3 Contacts , It separates the heat from the temperature , It can realize heating and temperature measurement at the same time , Therefore, the temperature drop of the soldering head will be detected more quickly , It's faster to warm up .
The power supply of soldering iron head is AC 24V, Thyristor can be used to adjust the conduction angle to adjust the heating power . as follows ：
This is a plan for foreigners , Iron tipped 3 Each contact is connected with red wire , Green line , blue line , Then the thermocouple is directly connected between the red wire and the green wire MAX6675, This is Meissen's thermocouple temperature measurement chip , It uses SPI Mode output temperature value . Between the blue line and the green line is the heating wire , Access to the lower left side of the thyristor circuit , It's used here 15.5V communication （ It should be used 24V communication ）,MCU The thyristor is controlled to turn on by optocoupler . The upper left side is the zero crossing detection circuit , It is necessary to signal the thyristor when crossing zero , In this way, the conduction angle can be accurately controlled .
There is, of course, another way of control , It's about using a full communication cycle , The temperature is controlled by controlling the ratio of the number of AC cycles to the total number .
The circuit is simple, too , It's using H Bridge control , Detection of zero crossing signal , Always on until the next zero crossing , When the next zero crossing, judge whether to continue the conduction .
The self-made circuit of welding station is very simple , The only difficulty is the procedure PID The temperature is controlled .
okay , Here are the self-made materials of these two welding platforms , Let's do it, old man . There is no clear to discuss .