Ownnemesis
28.04.2012, 13:18
Hallo ich hab da mal eine frage!
ich bau mir eine kleie steuerung für 3 schrittmotoren Aeg so26/48
Technische Daten:
- Betriebsspannung max. 5 V-
- Strangstrom max. 1 A
- Strangwiderstand 5 Ω
mit den oben genannten treibern!
im datenblatt steht
To achieve high step rates, the motor supply is typically much higher than would be permissible without active current limiting. For instance, a typical stepper motor might have a maximum current rating of 1 A with a 5Ω coil resistance, which would indicate a maximum motor supply of 5 V. Using such a motor with 12 V would allow higher step rates, but the current must actively be limited to under 1 A to prevent damage to the motor.
The A4988 supports such active current limiting, and the trimmer potentiometer on the board can be used to set the current limit. One way to set the current limit is to put the driver into full-step mode and to measure the coil current without clocking the STEP input. The measured current will be 0.7 times the current limit (since both coils are always on and limited to 70% in full-step mode). Please note that the current limit is dependent on the Vdd voltage.
Another way to set the current limit is to measure the voltage on the “ref” pin and to calculate the resulting current limit (the current sense resistors are 0.05Ω). The ref pin voltage is accessible on a via that is circled on the bottom silkscreen of the circuit board. See the A4988 datasheet for more information.
So mein Denglisch is not so gut! :)
da steht einstellen über poti im vollschritt mode ohne steps! da schalter er auf 70% der leistung!
verstehe ich das richtig das ich den strom so einstellen muss, 2 wicklungen a 1A -30% also auf 1,4A oder auf 0,7A für eine wicklung?
dementsprechend über den ref messpunkt u=r*i = 0.05Ohm*1,4A = 0,07V oder 0,035V für eine wicklung?
oder habe ich nen denk/rechenfehler?
ich bau mir eine kleie steuerung für 3 schrittmotoren Aeg so26/48
Technische Daten:
- Betriebsspannung max. 5 V-
- Strangstrom max. 1 A
- Strangwiderstand 5 Ω
mit den oben genannten treibern!
im datenblatt steht
To achieve high step rates, the motor supply is typically much higher than would be permissible without active current limiting. For instance, a typical stepper motor might have a maximum current rating of 1 A with a 5Ω coil resistance, which would indicate a maximum motor supply of 5 V. Using such a motor with 12 V would allow higher step rates, but the current must actively be limited to under 1 A to prevent damage to the motor.
The A4988 supports such active current limiting, and the trimmer potentiometer on the board can be used to set the current limit. One way to set the current limit is to put the driver into full-step mode and to measure the coil current without clocking the STEP input. The measured current will be 0.7 times the current limit (since both coils are always on and limited to 70% in full-step mode). Please note that the current limit is dependent on the Vdd voltage.
Another way to set the current limit is to measure the voltage on the “ref” pin and to calculate the resulting current limit (the current sense resistors are 0.05Ω). The ref pin voltage is accessible on a via that is circled on the bottom silkscreen of the circuit board. See the A4988 datasheet for more information.
So mein Denglisch is not so gut! :)
da steht einstellen über poti im vollschritt mode ohne steps! da schalter er auf 70% der leistung!
verstehe ich das richtig das ich den strom so einstellen muss, 2 wicklungen a 1A -30% also auf 1,4A oder auf 0,7A für eine wicklung?
dementsprechend über den ref messpunkt u=r*i = 0.05Ohm*1,4A = 0,07V oder 0,035V für eine wicklung?
oder habe ich nen denk/rechenfehler?