4 LEDs connected in series are a group, and 4 groups can be connected in parallel to the two poles of the battery at the same time. The resistor on the left side of the battery protects the LED.
The actual measurement requires a minimum voltage of 1.6V to light up a small LED light in the picture, and it can still emit light normally when subjected to a voltage of 2.1V. The output voltage of the new 9V carbon battery is 10V. In theory, each small lamp can withstand a voltage of 2.5V. But in fact, after 4 sets of LEDs are connected in parallel on the battery, the operating voltage of the new battery drops to 8.6V, so it is only about 2.1V to spread evenly on each LED.
According to the circuit diagram, the 16 LEDs are divided into four groups according to the following method, each group of internal small lamps are connected in series, the groups are connected in parallel, and the power supply is connected in parallel.
Bend the green LED pins into 3 different shapes, from left to right: the fourth layer (7), the third layer (5), the second layer (3) and the first layer (1 One, it should be red LED), and then use a soldering iron to solder the LEDs in series according to a group of 4. Note that the LED has positive and negative poles, do not connect them backwards.
The fourth layer is green LED 09-15, of which 12-15 is a group, 09-11 and 08 of the third layer are combined into a group. Note that the middle is separated, the four on the left are connected together, and the three on the right are connected together.
The third layer is green LED 04~08, of which 04~07 are a group. Note that one LED is separate from the other four.
On the second layer, note that although the 3 LEDs are arranged in a triangle, they are not actually connected to each other. There is a positive pole and a negative pole.
Solder the red LED to the second layer, and solder 08 on the third layer to 09-11 on the fourth layer.
A total of 4 sets of LEDs connected in series have now been obtained.
Connect the 4 groups of LEDs in series you just got in parallel. The fourth layer is completed.