Friday, July 31, 2015
Phone line jack polarity
It isn't so complicated after all - the phone line jack polarity only consist of positive and negative it's as simple as that. Picture just for future reference the phone line can power up an LED if connected to it. This gives an idea where to get free source of energy when it is desperately needed.
One simple circuit to step up voltage using LM2577 -Adj P+ chip. The schematic is from Texas Instrument and it works expected - and below is...