A typical laser ranging system should have the following units

 A typical laser ranging system should have the following units: laser unit, the laser receiver unit, the distance calculation and display unit, collimating and focusing unit, such as Figure 1.1 shows the system work, the laser emitted by the transmitter unit reflected back to the speed of light to reach the target, the receiving unit to receive the target distance, distance calculation and display unit. Figure 1.1 The laser ranging system schematic diagram of the laser the basic principle of distance measurement, laser ranging techniques can be divided into the laser time-of-flight ranging and non-time-of-flight laser range finder, two types of time-of-flight ranging, depending on the state of a laser, can be divided into pulse laser ranging and continuous wave laser ranging.
Its core is a PN junction formed by P-type and N-type semiconductor materials and semiconductor materials absorb solar energy, the PN junction photovoltaic effect can light signals into electrical signals, the Figure 3.l is a semiconductor PN junction photodetector schematic diagram schematic of Figure 3.1 the PN section photodetector when the PN junction in equilibrium, the interior will form a strong electric field of a self-built carrier depletion region at this time if greater than the semiconductor band gap energy photons into the semiconductor, PN junction barrier near the electron-hole pairs. these non-equilibrium carrier motion near the PN junction, PN junction, a strong electric field will be separated. green laser pointer is the 2G laser pointers with USB flash disks.
So to choose a reasonable parameter values, obtained from the circuit 555 cycles can happen to make the inductance near saturation, this design can improve the conversion efficiency of the circuit. Also, because the circuit operates in the saturated state, can adjust the transistor on-time control output voltage. ignored the tube voltage drop in the inductor current reaches the saturation, by the following derivation to calculate the output voltage on the inductor voltage is: V = L di dt (3.1) Therefore, the rate of rise of current conduction is: V-ion = dion Vi = dt of Li (3.2) where i on conduction flow LI current turn-on time t - on vi is the supply voltage, L, i Ll inductor. green laser pointer with remote control and U-disk laser pointers are on the top of the tool lists for teaching, lecturing and meetings.To ensure the safety and security of the customer when using green laser pointer
Assumed inductance recoil voltage equals the output voltage V 0, then when the cut-off of the transistor, the voltage across the inductor is V 0-V i is the rate of current in the inductor as: V ioff = dioff dt off = V0 VI L1 (3.3) t off is decided by the transistor cut-off time, such as the model for 3DK9 switching transistor completely cut-off time is about 1.5 microseconds, within this period of time, the transistor is fully closing, the current reaches zero.