Does a signal ride upon the dc voltage? If so, what is the peak to peak value of the signal? But if all you're doing is changing 3.5 v dc to 4.5 volt dc, then make a common emitter amplifier with a BJT capable of your load current plus 1 ma. The latter is necessary to keep the bias right. Don't forget to subtract the 2mv of saturation voltage when calculating your resistors. The gain of this stage is (4.5v-.2mv)/3.5v which is about 1.3 v/v. Use an emitter resistor and a collector resistor. No resistors are needed at the base, since the battery supplies a fixed 3.5 volts.I need to transform a 3,5V DC (generated by 3 LiMh batteries) into a 4,5V DC, but I can't use a different battery pack o another supply voltag.
Does anyone have a suggestion to solve this problem?
aaimi
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