Switch mode power supply w/ Voltage divider

[argonrepublic]

I have a power supply (ac adapter) It is 19 Volts and I need 16 Volts. I don't fully understand voltage dividers. I could make a voltage divider but the power supply is 90 Watts. I am assuming the a 1 watt resistor won't work or is the resisto wattage base on the wattage of the resistance?

 

[sawreyrw]

No, using a voltage divider would not be very practical. However, a simple series pass regulator would be a good solution and the losses wouldn't be too bad.

 

[geraldfryjr]

It depends on how much current draw is required that detrimines resistor disiapation in watts. jer

 

[gootee]

Yeah, 90 Watts is the maximum it should put out, if you let it. Your total resistance value would determine the current, and thus the power ratings required for the resistors. If you only need a watt or so, it could be done that way. But check out the LM3xx (and other) linear three-terminal regulators, at national.com (and others). It is a much easier and better way.