i have an unregulated power supply... transformer, bridge rec., capacitors. it was used for the stepper motors im using in my project. problem is it puts out...
1. The 6 holes are "vias" that make electrical connections between the A3977 pins on the top of the PCB to the traces on the bottom. Two are connected to VBB...
An unregulated supply is fine, but the voltage must be well below 35 volts. If the transformer has multiple taps, you may be able to re-wire it for a lower...
Getting ready to start up my THSTEP25 and have the following questions: On adjusting the "Internal PWM Current Control" for Itrip reference voltage. What and...
i have just powered up my boards. set all the voltages etc. all is fine. but cannot get my motors to run. not sure if its the boards or my comp. / cnc program....
Ok... The Itrip reference voltage is "Vref" given in the THSTEP25 datasheet on page 6: Vref = 1.6 X (desired current) The "desired current" is the stepper...
The first question is, does the motor "lock up" and hold position when the power is on? If so, then check your CNC software setup. If the motor does not lock...
Tom, What's the status of replacement PICs? You will remember I fried one of my original 12F675s by puting it in backwards, so I need to replace it with...
Hi Tom, I have assembled 3 boards, and two work perfectly (except for the problem with the PIC). The 3rd board has a different challenge. 5v is correct, and...
Hi Tom, I have assembled 3 boards, and two work perfectly (except for the problem with the PIC). The 3rd board has a different challenge. 5v is correct, and...
Sorry for the delay in getting back to you. First, new PIC's should be on the way soon. Meanwhile - With no PIC or a defective one, the digital inputs such as...
Hi, More info...the board seems to be switching between enabled and not, since I can turn the motor shaft with my fingers in step with the chatter. Is this a...
Hmmm... sounds like thermal shutdown. The chip disables itself when it gets to a certain temperature and then enables again when it cools a few degrees. ...
I'm making some progress. I disconnected the motor and compared readings between two boards, a good one and the one with problems. The problem board did not...
I admit that those readings are puzzling. You should be getting very high resistance readings (MegOhm or KOhm) between the power pins and the phases. On your...
Tom, What is the status of the PIC's for the THSTEP25 boards??? Notified you on 6-5-06 that I had received the wrong PIC's, you said send a private email with...
Hello, I just finished soldering together my board and I have a problem. when turning the power on to the board, my power supply starts beeping. It is a 24v...
Shaun, Electrolytic capacitors can be damaged by reverse polarity. Usually it is pretty spectacular because the high leakage current heats and boils the...
Hi, thanks for the reply. Yesterday I soldered together another entire board with all new components. When I applied power to this board I got the same...
I'm assuming that the beeping from your power suppy is an indication of overcurrent. What are the specs on your supply? Is there anything else that the...
... The power supply is a 24v switching power supply, not sure on the current rating but I was using it to power 3 IM483 drivers at 2.5 amps each axis. Now I...
Hi, I have scanned both sides of one of my boards. If you could take a look and see if you notice anything wrong with it I would appreciate it. I left the...
Shaun, It looks like you tried to send the photos as attachments to your post - this groups does not allow attachments. You can upload the files to the photos...
Ok, I don't see any glaring errors. One small point - Most of the resistors are supposed to be installed vertically, ie. leave one lead straight and bend the...
Here's an article on how to choose a linear actuator. http://www.ehow.com/how_4733789_choose-right-linear-actuator.html Seems like no one ever has the...
