What is the reason why a 9 string LED flash circuit with 555 is made of 555 and does not flash after

There are 4 questions:

1.After the LED string, another current-limiting resistor should be stringed. This has two benefits: limiting the LED current; It can prevent the 9 channels from influencing each other when they are connected in parallel, so this resistor is also called the current sharing resistor.

2.What is the supply voltage? You didn't give it out!

If 7 LEDs are connected in series, each LED needs to be rated as 2V, (or 3V, there are 2 kinds of LEDs, one is about 2V and the other is about 3V) The voltage is 21V, considering the 8050 saturation voltage drop and the current limiting resistor voltage drop, so the voltage of 24V should be used. In this way, the working voltage of 555 after using a 21V regulator tube is 3V.

3.R2 should string a fixed resistor of about 1k.

The 4 and 8 terminals are connected with a resistor (depending on the test supply voltage, 560 ohms for 24V) to the ground, which is used as the voltage regulator resistance of the regulator tube to prevent the voltage fluctuation of the regulator tube due to the current being too small.

In addition, the base of 8050 is better to add a pull-down resistor of a few k, which is more reliable.

When the capacitor is charged by R1 R2, the 555 output is high and the LED is on.

When the capacitor is discharged by R2, the 555 outputs low and the LED turns off.

It may be that R2 is too small, and adding an electrolytic capacitor of 100uf to the feet and ground may help.

9 and 7 strings = 63 LEDs are operated by an 8050, and the high current may also affect the NE555 operation.

Summary. Some LEDs use two chips in a lamp in reverse parallel, no matter what direction the voltage is, there is always a chip that emits light.

1W Zen Qi LED lamp beads 7 strings 12 and, direct DC power supply negative pole, do not He Zaoling connect to the positive pole, why is it on, the power supply is off. 7 strings of 12 parallel 1W LED lamp beads are only connected to the negative pole of the DC power supply and not to the positive pole, the power supply has a switch, and the power supply is off, why is it on? When the power is off, only any pole of the rock line will be lit.

Some LEDs use two chips in a lamp in reverse parallel, no matter what direction the voltage is, there is always a chip that emits light.

This is one-way, marked with the positive and negative poles, the seller said when the mu disturbed the purchase, there was no welding such as dry when I measured with a multimeter, I was welded on the 1W dedicated single aluminum substrate, with heat dissipation silicone grease pasted on the aluminum heat dissipation lamp shell, the lower side of the lamp shell has a PVC insulation pad, my power supply is still off, the slag hole is only connected to the negative pole or positive pole, the other pole is not wired, there should be no current circuit! With a 24V power supply, the voltage of the front-end lamp bead measured in this case is 8V, and the lower the voltage, the rated voltage of the lamp bead.

Is it always on? Or is it only for a short while?

Only disturb the hidden to connect to any spare section of the pole, all the time the slow rolling hall is turned on and on, and it will not light up immediately after disconnecting, or when any pole is connected, the power plug will not be lit when unplugged, but the power plug switch is not turned off The minimum gear (200 mV and 200 mA) of the multimeter can not measure the voltage and current.

The negative electrode releases the capacitance to the ground, just like the electric test pen is plugged in the fire wide rise and the line is not lit after letting go, and the pen is connected to the tail pin of the electric pen with a smile and the suspended wire, and the wire has a distributed capacitance to the ground and is conductive and cautious to stare at the light.

The LED light flashes on the circuit and does not flash in other places, what is the problem with this circuit?

The result of your query has been obtained for the uproar; Hello, LED light flicker is the presence of insufficient capacitance or insufficient inductance in the circuit, which causes current fluctuations, which in turn affects the working of LED lights. It is advisable to check that the capacitive and inductive components in the circuit meet the requirements, or consider adding capacitors and inductors to stabilize the current to solve the flicker problem. Warm and chaotic wide spike awakening:

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1) In the series circuit, the reason why one light is on and the other light is not on is that the light that is not on is connected by the short dress group.

2) In series circuits. One light is on and the other light is not on, indicating that the circuit is a closed circuit.

Otherwise, one of the two lamps in series will not be lit, so the lamp that is not or molded must be shorted (i.e., the lamp is in a short-circuit state), and the current passes directly through the wire, not through the lamp at all.

The most likely situation is burned, the common LED wick, the voltage drops to 3V when it is on, which is too high, and it needs to be driven by a special constant current driving circuit.

There are two reasons for this:

1: There is a lamp bead that is broken. Since it is in parallel, the voltage on the three lamp beads is the same. If it's bad, it won't light up.

2: The capacity of the power supply is not large enough, and the resistance of one of the lamp beads is large, so it is not as bright as the other two lamp beads.