| ??? 06/09/06 08:50 Read: times |
#118081 - I am having a go at this Responding to: ???'s previous message |
Thankyou everyone for useful suggestions,
Here is my feedback Richard Erlacher said:
I've never used anything much more complicated than a handful of npn transistors, or maybe mosfets, even for motors I could hardly You should ask yourself WHY this motor is "bipolar" and why you're using it. If there's no good reason then a unipolar type is probably preferable and much easier to grok. There are good reasons for using bipolars, but you have to have a good reason. RE Unfortunately the motor has to be bipolar, i would love to use a unipolar motor but this project requires a small motor due to space constraint and torque requirement is quite high for that size for example same size unipolar motor will give me 0.2N-m torque so I have to use bipolar rather tragically. I am also tempted to use transistor/MOSFET here but eventually the end product will have at least 16 motors, so controlling all 16 motors with transistors will make the whole circuitary huge. Russell Bull said:
With any combination of circuitry that is switching high currents and logic circuitry, having the same 0v rail is not a problem as long as it is wired correctly. You need to ensure the 0v currents for the motor do not run though your logic 0v otherwise you'll have major problems. Having a 'star' point for your 0v wires is a good start - your logic 0v, motor 0v and power supplies 0v all meet at one point. That is what I want to know, as you mentioned above that "STAR" point, so if for example I connect 0V of logic and 0V of 24VDC to pin 4,,5,12,13.Do I acheive this star point?? you mentioned motor 0V, where will that be?? as I have 4 wires coming from motor which I understand are connected to motor coils. I am having a go at this motor using the below schemetic logic, if some one please advice. I know I might blow something but well all is part of learning, but i really want to run this motor. Microcontroller--------> 74HC244(buffer)------> 74HC04(inverter) -------> L293D ------> PS2502-4(opto)-------> 20ohm resistor---- -------> Motor coil. (I can pull together a circuit diagram, but i am sorry I don't know how to upload it here, ) Regards James |
| Topic | Author | Date |
| comments on this link please | 01/01/70 00:00 | |
| Looks OK | 01/01/70 00:00 | |
| motor rating | 01/01/70 00:00 | |
| Measure phase resistance | 01/01/70 00:00 | |
| Pushing your luck. | 01/01/70 00:00 | |
| Common ground | 01/01/70 00:00 | |
| voltages | 01/01/70 00:00 | |
| Stepper Motor Control Handbook | 01/01/70 00:00 | |
| I'm not sure optoisolators will do ... | 01/01/70 00:00 | |
| I am having a go at this | 01/01/70 00:00 | |
| Optos... | 01/01/70 00:00 | |
| Posting diagrams, etc... | 01/01/70 00:00 | |
| working but would like to know about ths | 01/01/70 00:00 | |
Try ... | 01/01/70 00:00 |