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I see that you are using lead/ball screws for your table drives. Has that worked well for you? The smaller machines I have seen use a simple belt instead. The lead or ball screw seems like it should...

What kind of driver are you thinking about? Voltage Source? Current Source? Either will dissipate a LOT of power as heat. The current source could be configured to give higher step rates than a...

It looks to me like a 32V to 36V unregulated power supply is what you want for the -4 versions of those drivers. The data sheet said 2A continuous, 4A peak per motor, so something in the 18 to 24 Amp...

You should be OK, just make sure that the low voltage side can handle the current:

I_low_v = I_hi_v * (V_hi_v / V_low_v)

So your 240V current will be about 2X your 460V current.

BobH

They might be the same or they might not. They might be removed from boards, they might be stock from companies that went toes up, they might be complete counterfeits. Check out the Sparkfun web...

I don't think it too likely that it is a ground loop issue. I would say pop open the box on the AB switches and look at the switches. Most of those switches I have looked inside don't look like they...

I put a treadmill motor and controller on an old Southbend 9" a while ago. What I did was to fabricate a box that held both the motor and controller board. I put a power cord connector, fuse holder,...

With a stall current of 5 Amps, you are probably OK with this layout for the power section.

There is no good method of calculating decoupling caps that I have seen. I try to put a 0.1uF cap per...

What I mean by a separate path back to the power supply for motor ground current and logic ground current is that I would run a separate, heavy gauge wire from your Motor power connector to the...

Hi,
I looked at your schematic and I think it would be a good thing to add some .1uF and maybe some .001uF ceramic caps on the motor voltage to ground. Make sure that the ones on the motor voltage...

A useful tool for debugging serial communication problems is the Hyperterm app that comes with Windows or minicom with Linux/unix. You make a crossover cable with the data pins cross connected 2-3,...

I would be pretty surprised if 7V does not let the smoke out of a real TTL version of s 7404.
My ancient Motorola TTL data book says 5.5V is the maximum operating voltage for LS and I expect...

I used to work on a system that used two laser interferometers for position (X,Y) feedback back in the early 80's. It was a projection stepper for printing patterns on silicon wafers. The base of the...

A digital solution like a microcontroller would be the most stable, but you could also do this in an FPGA or in straight analog.

BobH

Hi,
Heat will be your biggest problem. As long as you have a way to keep the Geckos cool, it should be fine.


Bob

Hi Yervant,
It is hard to answer whether that chip can drive your motor long term without more information. If your steady state current is 50 mA, your power dissipation in an H bridge with 10 ohm...

The top two transistors won't saturate, they are running in emitter follower mode. The highest that the emitter of the top two transistors could be in an unloaded condition is 3.3-0.6V or 2.7 Volts....

Hi Scott,
Assuming that there are no defective parts, it doesn't really make much difference which side of the transformer you put the relay on. The transformer should not have enough inrush current...

If your power supply is not tripping the breaker every time you switch it on, there is a good chance that is is wired correctly. You are correct that there is a large current draw while the caps...

If you put a 100 ohm resistor from the input of your black box to ground, it will cause a current to flow to ground. That current will induce a voltage that can be calculated by ohms law, or if you...

Al is right, you need to know a little more about what you are driving. You can figure out what you need to turn the load off by connecting your voltmeter across the leads of a 100 ohm resistor and...

It may or may not be useful, but there is/was a very common darlington driver chip that was numbered: ULN2003. I think it was 4 or so darlington transistors in a DIP pack. It might be used as a a...

You have not mentioned anything about cable routing and connector assignments in your setup. Try routing the encoder cabling as far from the motor power wiring as possible. If you are going to put...

Is there a mechanical stop on the focus knob? One technique I have seen done is to issue more step pulses that it would take to move the complete length of travel and call the place where it stopped...

I agree with Neil's comment about checking to make sure that the gate drive is referenced to the FET source leads.

I have done a few of the current sense circuits like you are describing and...

It is hard to tell. From looking at CandCNC's docs, they don't show an output current capability for the step and direction signals. The only way to connect the Geckos is by paralleling the step and...

Digikey lists the surface mount version (620-1170-1-ND) for about $7US each in one lots. WWW.Digikey.com. First class vendor.

Bob

An unregulated supply is easy to build. For a 12 volt DC supply, get a transformer rated at about 9 volts AC and 1.5 x the current you want. For a 16 - 18 volt DC supply get a transformer rated at...

It is probably a couple of things. A 14 volt 3 amp motor will pull up to about 5x the operating current during startup if you were running it on 14 volts. Since you are running it on 24 volts, that...

I don't think it is bad power transitors. If it were bad power transistors, it would always move at maximum speed in the same direction when the EStop is released, whether the ribbon cable is plugged...