Questions in the analysis of the principle of the working process of the white photoelectric soldering iron tip
The voltage V3 generated at both ends of the thermocouple is very weak, which can be seen from the voltage division ratio of the LM358 pin 2 resistance, the maximum is about 100mV. In fact, the thermocouple only comes into play when the T12 is de-energized!
The timing circuit composed of 205 resistors and 104 capacitors on the 6th pin is not described. In fact, T12 is only powered on within this time period. When the 104 capacitor is charged to make V6 higher than V5, it will be powered off; after power off, V3 is no longer 24V, and the voltage V3 on the thermocouple and the set value V2 In comparison, if it is low, V1 is low, the capacitor 104 is discharged at a given time, V6 is lower than V5, and the cycle of T12 re-energization starts, so that the temperature of the soldering iron is kept constant.
The temperature setting V2 has a minimum value of about 10mV and a maximum value of about 100mV. T12 will continue to be heated by electricity since it is powered on until V3 is greater than V2, and then enters the above constant temperature cycle.
Except the timing capacitor 104, other capacitors are filter capacitors. In addition, the D and S marks of TPC8107 on the figure are reversed.
Schematic diagram of white photoelectric soldering iron
Baiguang soldering iron is the electric soldering iron produced by Baiguang Company.
At present, there are imported white photoelectric soldering irons, domestic white photoelectric soldering irons and many imitation white photoelectric soldering irons on the market; at present, electric soldering irons have developed from ordinary electric soldering irons to temperature-adjustable electric soldering irons, and now to digital adjustable constant temperature electric soldering irons.
