It also shows the large need of laser pointer in the market

It also shows the large need of laser pointer in the market.
High-pressure stability in the feedback loop from the power supply voltage, temperature and other factors, while making the high-pressure adjustable within a certain range. Back waves of the received pulse signal through the drive circuit of the APD, is converted to a voltage pulse signal input to the preamplifier circuit. Pre-processed signal, and then through an amplification and shaping operations can echo cutoff signal sent to the measurement unit, the time interval measurement. APD driver circuit. Figure for the high-voltage circuit to generate the 160V voltage, operating voltage of the APD. Current limiting resistor to protect the APD, to prevent the current burn transistor; C filter capacitor, close to the APD placed to filter out the high pressure generated by clutter. The practical function of laser pointer is conforming to the revise suggestion of the customer.
The output signal is provided to the follow-up circuit. The high voltage generating circuit. In the drive circuit of the APD, you need the 160V high voltage bias, the need to use a 5V supply voltage rise to 160V high-voltage generating circuit in the system. The circuit 555 oscillator consisting of a square wave generator to produce a certain duty cycle square wave to control the switching transistor on and off. Voltage of the circuit generated by the power supply voltage, temperature and other factors, therefore in order to produce high-pressure stability, and high-pressure adjustable within a certain range, high-voltage generating circuit in a feedback loop, as shown: front The amplifier circuit. Ranging when, due to the measured distance near and far. Function and performance of laser pointer is closer to the customer’s requirement.The green laser pointer has the large market need
Lead to the APD drive circuit output voltage signal change magnitude. In order to get a smaller amplitude change signal in the preamplifier circuit, selection of automatic gain control (AGC) function of the amplifier, as shown. Larger shaping circuit. Preamplifier circuit output signal amplitude, signal to noise ratio is not enough to meet the requirements of the measurement unit. In order to get sufficient magnification and a higher signal to noise ratio, subsequent signal processing, amplification and shaping. Amplification of the signal processing phase ratio of arithmetic circuit, a fixed gain. Signal shaping treatment using a comparator MAX913, the positive terminal of the input signal, the negative termination power. It is the specific detail for laser pointer .
Potentiometer to adjust the voltage, as a comparison voltage to extract a clean pulse signal in order to improve the measurement accuracy. The signal processing system design. , Due to atmospheric turbulence in pulsed laser ranging, tracking and pointing jitter, target attitude change will be introduced to the rapid fluctuation of the echo signal amplitude range goals to be determined.