# Thread: Which supply voltage and current for these PAP

1. ## Which supply voltage and current for these PAP

Hello all

Here the characteristics of my stepper motor,
How to calculate the output voltage and current of the supply
for three engines (serial connection)

2. The rule of the thumb is 10 - 25 x the rated the voltage.
As for te amps, it depends on the drivers. It's 3(motors) x the rated amps normaly but if the driver is based on a chopper (sort of current limiting) then it's 0.7 x 3 x 1.4 .

What drivers are you using ?

3. Thank's you for your reply I use a French product (3 axis integral board)

http://systrium.free.fr/Fiche_pratiq..._Motion3XA.pdf

if I understand well for a series connection the tension must be of 80V and current 3 A

4. Those drives appear to be rated for only 40 volts and 2 amps. For three motors, you would want a supply rated 5 amps or more. Your speed will probably be fairly slow using a series connection. You may get more speed by using a parallel connection with reduced current, running at the drives max of 2 amps. The static torque would only be 0.7 times the static torque for series connection, but it would not drop as much with speed, so you would probably get better speed with the parallel connection.

5. You are right a series connection reduce the speed,I can go to 120 mm/mn,over the torque decreases too much,but the speed for me it is not essential I have a Wabeco F1200 and I machine much metals,with a series connection I have a torque to 100% (1.4 A/phase my board work fine)
Currently the output voltage is to 26V if I increase the tension to 40V the performances will be better?

6. Maximum speed is proportional to supply voltage. If you go to 40 volts, your speed should increase to about 184 mm/mn (120 x 40/26). Increasing supply voltage will not increase the static torque.