First of all I am newbie in electronics, In my project i need 2 stepper motors and 3 servos. At present I have successfully made working 2 steppers and 1 servo, however when I added 2nd servo, my main stepper(stepper motor no 1) started fumbling i.e. i need to give a push to make it move. But when I removed 2nd servo it works fine. That is 2 steppers and 1 servo works fine.
I think my transformer/power supply is short of capacity. My transformer is of 1 amp, 12 volts, my servos are Acoms IC AS2. I don't have any identification for my steppers. All steppers and servos are given individual power supply. Can you suggest me how to overcome this situation. Let me know if you want further information.
First of all I am newbie in electronics, In my project i need 2 stepper motors and 3 servos. At present I have successfully made working 2 steppers and 1 servo, however when I added 2nd servo, my main stepper(stepper motor no 1) started fumbling i.e. i need to give a push to make it move. But when I removed 2nd servo it works fine. That is 2 steppers and 1 servo works fine.
I think my transformer/power supply is short of capacity. My transformer is of 1 amp, 12 volts, my servos are Acoms IC AS2. I don't have any identification for my steppers. All steppers and servos are given individual power supply. Can you suggest me how to overcome this situation. Let me know if you want further information.
Thanks in advance.
Without knowing the draw of all the devices it's impossible to say. Have you hooked up the multimeter to see what the current draw is? Have you tried a power supply with more current capacity?
bforu_gs:
I think my transformer/power supply is short of capacity. My transformer is of 1 amp, 12 volts, my servos are Acoms IC AS2. I don't have any identification for my steppers. All steppers and servos are given individual power supply. Can you suggest me how to overcome this situation. Let me know if you want further information.
Ok, this part is a bit unclear... You state you have a transformer providing 1 A @ 12 VDC (presumably from your local electrical mains). However, then you state that each stepper and servo has an individual power supply. Do you mean that the motors all have individual connections, perhaps with some step-down circuitry, or is there another source of power beyond the transformer you mentioned?
If it's the first case, then the power for the entire project is really being supplied by the AC-to-DC transformer and 1 A won't be enough current for all the motors. While there are ways to increase the current (at lower voltage, but that wouldn't be a problem in this case), you still only have a total of 12 W to work with. Therefore, you really need to get a AC-to-DC power supply with more current. I'd recommend getting one with a current rating of 4 A or 5 A if possible, at least 3 A at minimum. While the motors won't always all be drawing their peak currents, getting a supply that can handle that situation will avoid problems like the one you describe.
What's the nominal supply voltage of that servo? Ordinary bobby servos usually seem to be rated at about 6V - I don't recall seeing any rated for 12V. If you connect a 6V servo to 12V it could easily be damaged, and would also draw much more current than normal.
bforu_gs:
Far-seeker: Can you provide me easy circuit for 3/4/5 amp transformer power supply.
I misunderstood you, from your initial description I thought you were using the term "transformer" interchangably with "power supply" and you had a complete AC-to-DC commercial power supply and were stepping down from it. Instead you really were refering specifically to a transformer as part of your custom circuitry. Sorry for the confusion on my part...
Before we discuss changes to your circuit, I want to know more about this transformer, especially maximum rated current on the secondary winding (though a datasheet, if available, would be most helpful). Is it actually rated at only 1 A, or is that just what your circuitry is drawing from it?
By 3/4/5 I mean 3 or 4 or 5 amp circuit which i can replace in my existing power supply circuit.
Thanks for clearing that up. So we have a transformer rated for 12 W on the secondary side, which in turn limits the total power available to 12 W. So theoretically we could get a maximum of 2.4 A at 5 VDC and that's assuming no power is lost during the conversion from 12 VDC to 5 VDC. In reality you could expect efficiency to be above 85%, even a bit over 90%, but not 100%.
You need to get more power from the electrical mains, at least double (24 W total). Your situtation will determine what's most practical but the basic options are; put more than one of the same type of transformer in parallel with the transformer presently in use, replace the current transformer with one that can output more current (while the main criterion is the power on the secondary side, you probably don't want to increase the voltage level), or getting a pre-made AC to DC power supply (and in this case you might as well get one in the 40 to 60 Watt range). Once you figure out which option works best for you, then you determine the method to step-down the voltage while ensuring enough current.
