Basic circuit Boost dc dc converter
One of the advantages of switching power technology is that it can be used to raise or lower the voltage.
Gain converters are used in many cases, from supplying small supplies where higher voltages may be required to much higher power requirements.
There are often requirements for voltages higher than those provided by the available power supply - voltages for RF power amplifiers in mobile phones are just one example.
nokia 1280 light solution with pictures
measure the high frequency signal with the oscilloscope
The steps necessary to make the diagnosis and repair the defect of nokia 1280 light solution
1 measure the continuity of the different tracks between the lighting circuit components
2 measure the incoming voltage of cpu 1.8 v and its frequency 8khz on pin n 1 (mosfet spoil)
3 check the presence of battery voltage on the near n 3 (source of MOSFET)
4 check that the pin n 2 of MOSFET and link to the ground.
5 test the diode with a multimeter.
For the 1.8v to 8v voltage converter to work well, it requires the following components.
MOSFET, self l2503, diode, capacitor c2504
And feedback resistors r2514 r2518
Test all these components with a multimeter and change the faulty components.
Info, there are pictures on the internet show how to solve the Nokia 1280 light problem by removing the diode, the self and the MOSFET and make a jumper that is very dangerous for the cpu work, as it powers the diodes leds with voltage 1.8v
Serve to control the oscillation circuit.
To find the equivalents of the diode and transistor download its datasheet
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