1. Pin 7 gets connected to the 0v rail via a transistor inside the chip during part of the operation of the 555. If the pot is turned to very low resistance in the following circuit, a high current will flow through the pot and it will be damaged:
NE555的7脚不能直接将电位器接到电源正极，如果在调节电位器时阻值为0时，便将电源直接通过7脚到三极管到地，从而损坏NE555.
错误的使用NE555-7脚
2. The impedance of the 100u electrolytic will allow a very high current to flow and the chip will get very hot. Use 10u maximum when using 8R speaker.
输出端3脚如果驱动8欧的扬声器，将不能使用100uF的电容器，电容器将通过好大的电流，会使NE555发热严重，最大使用10uF的电容器。
3. The reset pin (pin 4) is internally tied HIGH via approx 100k but it should not be left floating as stray pulses may reset the chip.
NE555在工作时，不能将4脚悬空，这样很容易引入外部的杂信号。应该使用100K以内的电阻接高电平。
4. Do not draw 555 circuits as shown in the following diagram. Keep to a standard layout so the circuit is easy to follow.
不要使用下面的方法画
，这样的
很难读懂，应该使用通用的方法绘制
，这样才能更好的都懂
。
5. Here's an example from the web. It takes a lot of time to work out what the circuit is doing:
下面的图是根据芯片的排列管脚来绘制
的，这样的图要花好大的时间来读懂。应该尽量避免这样画图，
The aim it to lay-out a circuit so that it shows instantly what is happening. That's why everything must be in recognised locations.
Here is the corrected circuit: From this diagram it is obvious the circuit is an oscillator (and not a one-shot etc).
这是一个改正的电路，这样一看就知道是一个震荡电路。
6. Don't use high value electrolytics and high resistances to produce long delays. The 555 is very unreliable with timing values above 5-10 minutes. The reason is simple. The charging current for the electrolytic is between 1 - 3 microamp in the following diagram (when the electro is beginning to charge) and drops to less than 1 microamp when the electro is nearly charged.
If the leakage of the electro is 1 microamp, it will never fully charge and allow the 555 to "time-out."
不要使用高阻值电阻和大容量的电解电容来产生长的延时时间。这样是非常不准确的。
7. Do not connect a PNP to the output of a 555 as shown in the following diagram. Pin 3 does not rise high enough to turn off the transistor and the current taken by the circuit will be excessive. Use an NPN driver.
不使用PNP三极管连接到NE555的输出端。应使用NPN三极管驱动。
