General description
UM0527
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The power supply unit provides two outputs used in UPS blocks: +15 V for most of the
analog circuits and +5 V for the microcontroller. The switching voltage converter was built in
step-down topology with an integrated regulator L5970. The microcontroller is supplied by
linear reg5 V U3 LD1086V50. The switching regulator is controlled by the
microcontroller ON / OFF signal and the BUTTON signal from the front panel ON/OFF
switch. Additional supply is switched on by optocoupler SFH620 powered from the mains.