The green light emitted by green laser pointer can be seen miles awayeven during the daylight

This error signal uc by controlling the signal generator to control the gain controlled amplifier, When Ui decreases leaving the output Uo reduce, increase the detector circuit control signal UAGC will gain K, so that Uo tends to increase Ui increases leaving the output Uo increases, when the detection circuit to generate control signals UAGC will gain K decreases, so that Uo tends to decrease. In either case, the continuous cycle of feedback loop causes the output signal amplitude Uo remain basically unchanged or only in a smaller range of changes. There are two key performance indicators of the AGC circuit: one is the dynamic range, and the second is the response time. The customer can plug the desk charger of  laser pointer    into the socket.
Dynamic range AGC circuit automatic control circuit voltage error signal to eliminate the voltage error between the output signal amplitude and the requirements of the amplitude of the output signal. So when the circuit reaches equilibrium, there will be a voltage error. Consider the actual requirements of the AGC circuit, on the one hand, the output signal amplitude changes as small as possible, which requires the output voltage amplitude of the error as small as possible; the other hand, want to allow the input signal amplitude range the bigger the better. Therefore, the AGC dynamic range within a given output signal amplitude range, allowing the input signal amplitude range. This shows that the AGC dynamic range of the greater, the better the performance. However, we still suggest that the customer protect  green laser pointer well.
The response time of AGC circuit is controllable gain amplifier gain control to achieve restrictions on the output signal amplitude changes, the gain changes depending on the input signal amplitude changes, so they requested that the response of the AGC circuit is necessary to keep pace with the input signal the rate of change of amplitude, but also does not appear anti-modulation phenomenon, this is the response time characteristics. The so-called anti-modulation is when the input amplitude modulation signal, the useful amplitude modulation wave amplitude change is offset by the control role of the AGC circuit. Therefore, the requirements of the AGC circuit is: the smaller of the input signal, the AGC circuit does not work, only when the input signal increases to a certain extent, the AGC circuit from the control, so that the gain is reduced with increasing input signal. Therefore, we recommend the durable and sturdy case for  green laser pointer .
To achieve the above requirements, there must be a change with the external signal strength control voltage or current signal, the use of this signal to automatically control the gain of the amplifier. This design uses the DC component of the half-wave detection circuit outputs the AGC control signal. The role of the photodetector of the photodetector is the photoelectric effect of the use of substances to convert optical signals into electrical signals. Its performance significantly affect the properties of photovoltaic systems, which can reduce the volume of the system, to reduce the weight of the system, increase the role of distance. The case of  green laser pointer is durable enough.
In the military, space technology and other scientific technology and industrial and agricultural production, photoelectric detectors are widely used. The performance parameters of the photodetector due to the many types of photoelectric detector characteristics and requirements are different. But as a photoelectric detector used to detect the optical signal and transform it to a corresponding electrical signal, the following characteristics and requirements of [7] [8]: a detection sensitivity: the sensitivity is used to describe the degree of sensitivity of the detectors of optical radiation , defined as the output changes with the incident light unit power ratio of 16 Shandong University of Science and Technology BS thesis phase laser ranging technology light detectors. The sensitivity of the evaluation device, the output of the input volume with the RMS (root mean square value), and the nature of the radiation source.  green laser pointer  has the high power and big size.