Build Thread- Berger Lahr RDM 545 5 phase stepper datasheet

[jimbostlawrence]

Hi all,

I've spent the past few weeks trying to get information on an old Berger Lahr stepper motor : RDM545/100LTA 1W 5-phase, 0.5A, 8 Ohms/winding, 10 wires (5 pairs) I worked out which wires were connected to which wires, and built a simple PIC circuit to drive some TIP120's only to find that the motor jumps around. I also tried to energise 4 and cycle one to be in the off state in the hope it'd work and not be a bipolar motor.

It's a bipolar motor Managed to get one of the guys at Schneider Electric (bought out Berger Lahr a few years ago) to dig deep and he came up with a datasheet from the 80's (West Germany on the bottom lol!).

It's all in German, but obvious what the data shows including clockwise/anticlockwise rotation coil sequences using forward/reverse currents on multiple coils.

Thought I'd do the right thing for you guys and post it here as there is so little information on these beasts out there!

See attached file:

Best regards

Jimbo SL

[Markus53]

Driving a 5 Phase stepper is a little more complicated than 2 phase ones

I made PCB that uses a Atmel to drive 5 Phase motors up to 1,5 Amps a few years ago, still have some lying around if anybodies interessted


Greezt,

Markus

[jimbostlawrence]

Hi Markus,

Thanks for getting back to me.

I've just about build the circuit (past few days) using a 16F84A PIC to control 2 and a half L298N's which allow you to control 2 coils bi-directionally - the motor is a 5 phase bipolar motor which couldn't have made things any worse for me!

What I've tried to do is use a couple of 595 8 bit shift registers which I feed serially a 10 bit number that tells the L298's which coil to switch on, and in which direction (load the 10 bit number into the 595 and then clock the shift register to the output register, presenting the 298's with the current phase conbination.

Not sure if your Atmel would do bipolar or not. If my circuit fails, I'll gladly get back to you.

Many thanks

Jimbo SL

Originally Posted by Markus53 Driving a 5 Phase stepper is a little more complicated than 2 phase ones I made PCB that uses a Atmel to drive 5 Phase motors up to 1,5 Amps a few years ago, still have some lying around if anybodies interessted Greezt, Markus

[jimbostlawrence]

Hi Marcus,

Once again thank you for your kind offer of an Atmel circuit to drive the 5-phase motor. I have however just finally taken the time to finish this circuit. This morning I connected the motor. Only one logic error - had cut a track in error, soon rectified. Circuit now drives the 5-phase motor, either direction, at whatever speed it can, completely under control of a 16F84A, with RS232 comm's to a PC.

Now just need to write the final routine to let me send direction/speed parameters from a hyperterminal or MatLab. The actual aim is to put this back on the microscope from whence it came and allow MatLab to carry out some autofocus algorithms. Nifty eh?

Best regards

Jimbo

[joel383]

I see lots of broken slides in your near future! lol j/k

very nifty sir.

[jimbostlawrence]

Originally Posted by joel383 I see lots of broken slides in your near future! lol j/k very nifty sir.

:P Job done, just hooked it up to the microscope. Works a treat. I did have to adjust the coil settling time parameter as it was trying to move the motor too fast for too little current (keeping this at a minimum for obvious reasons) - this is because, as expected, the motor acts a little differently under load.

Just need to do some nifty auto-focus routines now :P

Your point about broken slides lmao... I understand where you're coming from completely

Cheers all

Jimbo