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that is one uncommon and expensive IC, is is new or old? the company seems to be N.Y.C yet only available from China? very interesting though. took a quick peek at the data sheet, and looks promicing. I looked to the top US suppliers and no avail.
that is one uncommon and expensive IC, is is new or old? the company seems to be N.Y.C yet only available from China? very interesting though. took a quick peek at the data sheet, and looks promicing. I looked to the top US suppliers and no avail.
Razeen, ...............I am a wee bit overwhelmed by the data sheet, to be honest..... what are your thoughts on a digital pot (say non -vol with up/down?) or dual? I am concerned about simplicity? trying keep components to a min.
the dea is you can make a programable pulse generator by inserting this IC in between. instead of using a digital pot and set your values to the oscillator, you can use this in loop with an osciallator to give a range of frequencies. let me see if i can post you a simple CCT when i get free time
I kind of understand what you are saying, but how is it going to be adjustable on the fly? as I understand the freq. is adjusted through 5 digit binary. I dont want to fiddle with switches or use a P.C. to run the binary code. I assume the fixed speed is the external 555, and the adjustable is the internal clock controled externaly some how?
you discussed about digital pot, so i assumed your inputs are binary / logic. what are your control inputs? you need to have only two speeds? or variable on both directions? the IC provides programable delay, as well as can be used as a variable frequency pulse generator as you think. i didnt use it for any application yet, this is what understand from the datasheet. also you can use it with a astable multivibrator to delay the change of state so that can get different frequencies too.
thankyou for your help again.........I am currently using mach3 program to run motors, but seeing such simple operation i am switching to isolated circut, you helped with the function greatly, have tested and Board ready to print. the speed part is a separate board for now., so basicly the FEED is the speed that needs to be varaiable, then the other speed is to return to home position, which once I get setup will never change (but needs to be adjustable for now to get maximum return to home speed)to clarify you helped with the post - motion control(forward reverse stop/reset/......)so I guess my mistake on the original post. technicaly I was after an UP/DOWN button.... the rheostat works but am unsure of the stability af what I have done. RA is about .9k and RB is 1k pot then RB 0k for high speed and as data sheet states RA 1k or above
Razeen,I have a difficult time explaining. SO....... i will begin new, the process. push button(leaves home switch inverted setting the s-r latch......... ) then oscillator needs to be variable for feed. Limit reached...... Pause 5-10 seconds, then speed home.( maximum speed for stepper motor without ramp up, {I dont think anyone here could make ramp up oscillator?} well maybe you? in theory a large cap and a small resistor could create a voltage controled osc.? .........I dont need that part though....
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So answer to your question CMOS logic and low speed variable by user. high speed one time adjust to equiptment needs.
Crosslakeguy,
I gave up on you because you keep going off on tangents.
I told you that a 4066 would work. I don't think you ever believed me.
Alec showed you how to use them. You pretty much ignored him.
I asked you here for details. You promised to get back with them, but never did. I was going to design a circuit that requires no analog switches or relays.
I haven't used digital pots. I could figure out how to use one from the datasheet.
A digital pot can be used as a rheostat, but there are a lot of details to attend to. Low-cost units have huge resistance tolerances, like ±20-30%, and resistor tempcos of 200-300ppm/°C. You can buy low tolerance, low tempco units, but they are relatively expensive, and have peak current specs that have to be adhered to.
You can use a low-cost unit for your application in ratiometric mode, which is what they are designed for, but it would require more parts, like an op amp, a transistor, and a couple of resistors.
I agree about the tangents!I am not any where where I can do any tests, so I realy was not ignoring Alec. Or your advice, I can only look at data sheets and the recomedations of you and others.. I guess I am looking to anyone and everyone for different solutions to the same problem. I assume that is what this forum is all about? I think most Importantly about any dialog is to know what is being asked, and then formulate the best answer to the question. I wish I could sit down with any one of you for a day or two.
the tolerances are not that important for my application. I would like to keep the components to a minimum. (moreso because I cannot follow complex schematics) my logic is........ there has to be a better way of doing things? whether loading the dishwasher or playing solitare? call it OCD If you like. and Razeen, Your IC LS7210 is a great idea! I don't understand why it is so hard to get? It seems like an awesome IC? but the adjustment manualy could be difficult ( I said electronicall controled, so my bad)
Please tell us the high and low frequency ranges, in hertz (not rpm).
EDIT: This forum appparently will not allow shouting. I typed the above sentence in CAPs, and it converted them to lower case.
Sometimes SHOUTING is appropriate - like now.
Hey, so low 100hz- 330hz and high 330hz- 1.167khz. an active low will run low, an active high will activate high. the high speed and low speed run the same motor. those numbers don't need to be exact, It is just what the rpm's worked out to. the low numbers are definite values. The high could possibly be from 600hz to 1.2khz as I probly wont use between 330hz- 600hz anyways? the speed increase could be as high as 25hz incriments, lower would be better. when I get back home I will be ready to try these disigns, yes Alecs too. which I do have a couple questions about as well. post #1 I should have devided by 60 not multiplied, oops. no wonder you are asking........ Sorry! p.s I looked back at the digital pots spec. sheet, like you said +20 to -20% wow! It would still work for me...... but wow!
yes, for the most part, the circuit I made the duty cycle was to long...... so I inverted the signal. I don't remember the specifics, but a shorter duty cycle functions better than a longer one. the circuit recognized a pulse better than a long duration on time.. but I think a square wave is fine too?
yes, for the most part, the circuit I made the duty cycle was to long...... so I inverted the signal. I don't remember the specifics, but a shorter duty cycle functions better than a longer one. the circuit recognized a pulse better than a long duration on time.. but I think a square wave is fine too?
You are using stepper motors and the way to control the speed is by controlling the pulse rate. I advise you to give up the idea of having a variable frequency by controlling the oscillator instead you can use a counter to divide digital clock / pulse from a fixed squire wave generator. The division can be set manually by simple section or even can be by logic inputs.
Also you entire circuit can be minimized by removing limit switches since you can exactly control the no of pulses delivered and reverse the motor after a short delay. So it’s not necessary in this case to have two different circuits. Say you have to give 1000 steps / pulses to move from “home” to the destination. Then stop for few more pulses depend on the time delay required. Then reverse the motor the same signal would re-direct your pulses through dividing counter giving you a longer time for the system to return home.
It’s in my mind how it can be done as I described, try if you can work it out, if not I can give you some sketch.
Limit,HOME...... Yes that would work, however It must always know where home is....... on startup .or mid-cycle start.......cannot assume always at home position. like a printer. cycle on..... find home....... all values assumed after that 1000 steps is 1000 steps. I understand what you are saying but is this possible without a microcontroler? as I said efore I am running this currently on a cnc program called MACH3....I bought a PIC programming book, but without personal help it is way to complicated for me to understand? I have looked at basic programs and others, I wish I understood them?....... thats why I am trying to do on off type circuit? and yes Idealy I could adjust the pulse rate and number.........and if pigs could fly.....a ramp up frequency on high speed.\ for return to home/ the more I try to learn, the more I undertand that I don't know....
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