With an electrical transformer, the ultimate goal is to convert the ultra-high voltage that comes streaming in from the power plant and turn it into a lower-voltage, more usable form. After all, if you were to plug a high-voltage power line (which can be up to 69,000 volts in urban areas) directly into say, your phone charger (about 5 volts), let’s just say it wouldn’t be pretty. Circuit Breaker Wholesale