cufflinks

Typically, the laser internal LD and back light detector PD integrated, as shown in Figure 2. Among them, the LD has two light output surface, the light output of the main light output surface for user times the light output surface of the output light (back light) received by the photodiode PD, the light generated current is used to monitor the LD state. Back monitoring current main output surface of the optical detector light output power of a linear relationship between appropriate external circuit can be designed to complete the automatic power control of LD based on the coupling characteristics of the back light detector LD. The LD driver control circuit design. It can be seen from Figure 3: LD and monitoring diode is integrated components. The two kinds of laser beam lights will come out of the two apertures of laser pointers. Yellow Laser Pointer
Current into the LD APC circuit pre-bias current. APC circuit current negative feedback circuit to suppress the change due to temperature change, device aging caused by the optical power. The APC circuit part of the back optical feedback bias control, PD photodiode monitoring of LD in the semiconductor laser components back the output optical power. Back to the output optical power output optical power can track changes through the closed-loop control system can adjust the laser current to achieve the purpose of stable output optical power. APC circuit shown in Figure 4 op amps 1, 2, and transistors Q1 and the external circuit, the circuit is a transistor as the core negative feedback system. Whether laser pointers is worthy being bought by them.
Has the function of the automatic stabilizers laser light output power. Feedback taken from the LD back light, back light monitor diode detected and converted into a corresponding current, filtered by capacitor C1 into the op amp inverting input, the current signal is converted into a voltage signal V1. Op amp +2.5 V LM336 op amp with the input terminus of stable reference source and change R5. The output of the reference voltage V2, can be adjusted by variable-bit device. In the instant of the voltage coupled to the drive circuit, will produce a larger impact on current and instantaneous current change will affect the life of the semiconductor laser. In addition, under normal circumstances, the supply voltage AC 220 V provided by the transformer rectifier drive circuit voltage. To enhance the quality and performance of laser pointers. Zumba DVD
A software error, can not simply be attributed to an individual's responsibility, some errors may be produced not for technical reasons, may come from chaotic project management. Should analyze the processes of software projects, process improvement to find the cause of the error and improved measures. Misunderstanding number three: software testing do not ask random personal multi-line. Many people think that software testing is to install and run the program, the little mouse, press the keyboard. This is caused by specific techniques and methods do not understand software testing. Along with the improvement of the development of software engineering and software project management experience, software testing has formed an independent technical disciplines, evolving into an industry with huge market demand. The manufacturer should try the best to improve the design and technology of laser pointers.