Hello everyone. I am new to these forums and fairly new to circuit building. I am currently trying to convert an LED children's toy that operates on 3 AAA batteries to power it from a 5v wall adapter. I know that 3 AAA's in series is 4.5 volts. Would a single resistor placed in front of the wall adapter's cable to bring the voltage down .5 suffice or is there something more efficient/ stable that I need to do? Any input is greatly appreciated.