i have an old electrical blacksmith blower. the motor doesn't include a built in transformator. it just needs an it has an input of 3 Amp and 28 Volt.but i don't know if it's Alternating or Direct current.how do i test this?
Cut the wire, and connect with an LED rated for that amperage/voltage. Turn the LED around so and test to see whether it lights one way or both ways. If it lights in one direction, it's DC if it lights in both directions, AC. Chances are that it's a DC motor, and requires the input cable to have a small transformer(usually situated right next to the plug) **edit** I may as well explain why this works. An LED will only light if the current is flowing through it one way. With DC it will light only when the current is flowing through it the correct way. With AC current, it will strobe regardless of which way the LED is aligned.(but probably too fast to notice)
Input is AC, output is DC
When we say DC, you will be using battery cell as a source of current/electricity while AC, it is connected directly.
I think we missed something here. The question is about a motor and all the answers are talking about a power supply. I don't know the answer, but checking for the voltage output of a motor just doesn't make sense.
First look where it write 28v/3A(label of the motor) and if you see a sign like ~ then is a AC motor if it is = then is a DC motor. If the label doesn't have this indication use a transformer with a AC 24 to 28V/3A output and connect it to the motor.If the motor start to spin it is a AC motor and you can use it,if it only makes a humm and not spinning then it is a DC motor and you need a rectifier bridge between the transformer and the motor! ****EDIT**** OK!Another way to find out what you want is by take it apart to see if it has brushes and magnets(this means it is a DC motor) or the rotor of the motor is solid iron with a ring of aluminum(no coils on it ,only on stator) that means it is a AC motor! *****edit****** Or put in series with the motor a 100W light bulb and use the power line(220 or 120 I don't your power line voltage),only for a little time,and if the motor start spinning it is an AC motor if not it is a DC motor(the bulb will act as a fake load to take the extra voltage). Good luck!
