[Fabric8r]

This is the specks on the motor I have.
SEM small electric motor, perm magnet DC servo motor
Cont stall torque 3NM Tenv
Max rpm 2400 Volts 142 Pulse amps 30
Tacho 9.5 Volts/1,000 rpm insul F

I want to use Rutex drives and I found this formula on there web site but I cant understand some of the acronyms Thats where I need the help. Im trying to figure out what drives I need. I would also like to understand how you get this.

Heres the formula:
A servo motor data sheet may include graphs for torque in relation to current and speed in relation to voltage, But quite often a motor specification will show only the Kt constant in Nm/Amp or oz-in/Amp and Kv constant in Volts/kRPM. To properly size the drive needed, you need to determin the current and voltage required to produce the desired motion.

The calculation of the current required using the Kt parameter is very straight forward: Divide the required torq by Kt to get the current. For example, If the required torque is 20 lb-in (320 oz-in) and the Kt=32 oz-in/Amp, then 320/32=10Amps. this value is the current that the servo dive has to beable to provide.

What do these Aconyms Mean
Nm
Kt
Kv
kRPM
Thank you for any help you can provide.
Scott W.

[mykow]

This is the specks on the motor I have.
SEM small electric motor, perm magnet DC servo motor
Cont stall torque 3NM Tenv
Max rpm 2400 Volts 142 Pulse amps 30
Tacho 9.5 Volts/1,000 rpm insul F

I want to use Rutex drives and I found this formula on there web site but I cant understand some of the acronyms Thats where I need the help. Im trying to figure out what drives I need. I would also like to understand how you get this.

Heres the formula:
A servo motor data sheet may include graphs for torque in relation to current and speed in relation to voltage, But quite often a motor specification will show only the Kt constant in Nm/Amp or oz-in/Amp and Kv constant in Volts/kRPM. To properly size the drive needed, you need to determin the current and voltage required to produce the desired motion.

The calculation of the current required using the Kt parameter is very straight forward: Divide the required torq by Kt to get the current. For example, If the required torque is 20 lb-in (320 oz-in) and the Kt=32 oz-in/Amp, then 320/32=10Amps. this value is the current that the servo dive has to beable to provide.

What do these Aconyms Mean
Nm
Kt
Kv
kRPM
Thank you for any help you can provide.
Scott W.

Nm newton-meter, this is about 8.85 lb-in
Kt torque constant, this relates amps to torque
Kv voltage constant, relates volts to speed
kRPM k (thousand) RPM, revolutions per minute. so 2 kRPM is 2000 rpm

From the spec on that SEM motor it uses a tachometer. Most of the rutex drives want to see an encoder, so you'll want to check if you have that also.

30 pulse amps probably means that's your peak current. That's usually about five times your continuous current, so you can figure on about six amps continuous. I think rutex has a 100v/10A model and a 200v/20A model. Your motor will probably run on the 10A model (10 > 6), but your speed will be limited to 100/142 * 2400 rpm = 1690 rpm because the voltage of the drive is a little low for the motor. So you could go with either drive but you'll get slightly limited performance with the first one.

[Fabric8r]

In another thread I was told I should use 170Vdc powersupply to drive my motors. I was thinking of going with the Rutex 2020 drives there rated at 200V/40Amp does this sound like they will work.
Thanks for your information its greatly appreciated.