Hi,this driver will not be interesting people who can buy special purpose driver for LD.This driver contains parts that are cheap and easily obtainable in the whole world.This driver will be interesting people who have only three battery(3.6v) or only single li-ion(3.7V) and cant find driver that work on such small voltage difference and voltage drop.If you build this driver with SMD components dimensions in double layer PCB are around 20x20mm with height of 8-10mm depending of used components.
Characteristics of this driver are:
Input voltage 3-7V.
Output voltage 1.25-10.7V
Output current: 1A(Extended to 1.5A,read text).
Efficiency 80-87%.
First stage of this driver is MC34063 Boost converter that step up voltage from for example 3.6V to 5V.Second stage is LDO regulator which step down 5V to 3V or lower for laser diode.
Calibration is pretty easy.First put both trimmer in middle position.Example nr.1 If your input voltage is for example 3.6V drive trimmer R2 to 5V(if you go over 5V power dispassion will be bigger on LDO regulator and efficiency is decreased).Example nr.2 If you input voltage is 7V set trimmer R2 to 10V which is maximal allowed input voltage of LM1117.When you set R2 trimmer, then adjust final output voltage to laser diode with R3 trimmer.
LDO regulator is connected to regulate voltage NOT current because to maximize efficiency.If you have good cooler for laser diode they will not pull more current and can certainly work(I have laser pointer with LM1117 with voltage regulation and they work without any problems until have good cooling)
If you need more current connect two LM1117 in parallel and current will be 1.5A(which is maximal current for MC34063).
That all what I can say about this driver.I hope they will help someone.
Characteristics of this driver are:
Input voltage 3-7V.
Output voltage 1.25-10.7V
Output current: 1A(Extended to 1.5A,read text).
Efficiency 80-87%.
First stage of this driver is MC34063 Boost converter that step up voltage from for example 3.6V to 5V.Second stage is LDO regulator which step down 5V to 3V or lower for laser diode.
Calibration is pretty easy.First put both trimmer in middle position.Example nr.1 If your input voltage is for example 3.6V drive trimmer R2 to 5V(if you go over 5V power dispassion will be bigger on LDO regulator and efficiency is decreased).Example nr.2 If you input voltage is 7V set trimmer R2 to 10V which is maximal allowed input voltage of LM1117.When you set R2 trimmer, then adjust final output voltage to laser diode with R3 trimmer.
LDO regulator is connected to regulate voltage NOT current because to maximize efficiency.If you have good cooler for laser diode they will not pull more current and can certainly work(I have laser pointer with LM1117 with voltage regulation and they work without any problems until have good cooling)
If you need more current connect two LM1117 in parallel and current will be 1.5A(which is maximal current for MC34063).
That all what I can say about this driver.I hope they will help someone.
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