Tom just as a reminder, that .1uf ceramic disk cap, that is not on the schematic, goes from vcc+ (pin 8) to ground, or vcc- (pin 4). At least that is my understanding. You probably were aware of that, don't mean to be a backseat driver, okay I'll stop now. 🙂
Wish I could start on building the splitter, but my finances prohibit until around the 1st of the month. I have the same generator you have, only it's in a small plastic case. I think I'll mount the case face in my finished chassis box for access. I've been playing with that generator, and it seems very accurate, certainly more than the little 3 phase generator. I don't have an oscilloscope (can't believe I haven't bought one yet), but do have a true RMS voltage meter that measures frequency pretty accurately. It says my 3 phase generator is off by at least 1hz at 60 (can't remember exactly, had a very busy day), and reads right on for the DDS.
twystd
Wish I could start on building the splitter, but my finances prohibit until around the 1st of the month. I have the same generator you have, only it's in a small plastic case. I think I'll mount the case face in my finished chassis box for access. I've been playing with that generator, and it seems very accurate, certainly more than the little 3 phase generator. I don't have an oscilloscope (can't believe I haven't bought one yet), but do have a true RMS voltage meter that measures frequency pretty accurately. It says my 3 phase generator is off by at least 1hz at 60 (can't remember exactly, had a very busy day), and reads right on for the DDS.
twystd
Hi Twystd
There is never to much information. I know what the circuit is doing only because Hans said it is. I have been reading up a little on the op amps etc. But the information is all over the place.
If you know where there are some brussless DC motors or a 3 phase motor like yours let me know.
Thanks Tom
There is never to much information. I know what the circuit is doing only because Hans said it is. I have been reading up a little on the op amps etc. But the information is all over the place.
If you know where there are some brussless DC motors or a 3 phase motor like yours let me know.
Thanks Tom
Yes, 0.1uF caps have to go from pin 8 to pin 4 on the PCB, as close as possible to every op amp to prevent it from oscillating.
Hans
Just for completeness, I have added the design for an automatic frequency switch.
With a notch filter on 60 Hz, the output "relais" is either 24 Volt with 60 Hz at the input or 0 Volt with 81 Hz.
A small 24V relay, like the IM07TS, can be directly switched by U6.
This relay has 2 contacts, so either one or two resistors can be switched.
So, when going from 60 hz to 81 Hz, you won't have to bother with changing the RC combination(s) in the phase splitter.
Input signal is the same as for the splitter, directly after the 1uF input cap.
Hans
With a notch filter on 60 Hz, the output "relais" is either 24 Volt with 60 Hz at the input or 0 Volt with 81 Hz.
A small 24V relay, like the IM07TS, can be directly switched by U6.
This relay has 2 contacts, so either one or two resistors can be switched.
So, when going from 60 hz to 81 Hz, you won't have to bother with changing the RC combination(s) in the phase splitter.
Input signal is the same as for the splitter, directly after the 1uF input cap.
Hans
I forgot to mention that for the frequency switch a LT1885 op amp has to be used, having 4 opamps in one package.
Hans
Hans
Very cool Hans, that automatic switch makes the operation so much handier. Now, if I could just get my UD-B DDS signal generator to power back up to where I had it set, I could just buy 2 of the $30 kits feed the automatic frequency switch with each in parallel. With a DPDT switch, I could switch the power supply back and forth between the 2 generators to change speed. That way I could dial in, and preset each generator to exactly the right speed, after that the speed change would be just a throw of the switch.
Tom, I see by looking at the udb 1005s dds generator, and saw this quote on an auction site "10 set of parameters with storage and recall functions". Have you figured out how to do that? That would really work with Han's automatic frequency switch. All we'd have to do is dial it in for the 2 speeds, for exact frequency and amplitude, and store those two sets of parameters. To switch speeds, all we'd have to do is call up a stored set of parameters. How cool would that be?
twystd
twystd
Maybe it's about time to start thinking of designing a PCB to include all things discussed so far.
I'm can be the one to do that, but I don't want to be involved in the production c.q. distribution. My part will be to delivering the Gerbers.
Let me know if there is enough interest in that.
Hans
I'm can be the one to do that, but I don't want to be involved in the production c.q. distribution. My part will be to delivering the Gerbers.
Let me know if there is enough interest in that.
Hans
Hans, I've been thinking along those lines myself, but I'm not educated enough to pull it off, however you obviously are. I'm certainly interested, if pointed in the right direction. I would be more than willing to look into production with advice, distribution wouldn't be a big deal for me. I ship and receive things all the time via USPS, I can schedule pickups on-line. Sometimes it's a problem shipping internationally, but it's certainly doable. I'll have to fill out a form or two IIRC. Postage and packaging costs could be easily handled through PayPal. I'm retired, and spend a lot of time at home, so waiting for the postman to show up won't be a problem. If someone else is interested, please feel free to step up to the plate, won't hurt my feelings.
twystd
twystd
BTW, I'm compiling a parts list as a project on the Mouser Electronics site (saved there), and another on Digikey for the stuff I can't get at Mouser. All resistors are .1% precision resistors, and 1%, 2%, and 5% capacitors I figure the 30nf (1%) and the 330nf (2% couldn't find a 1%) caps in the splitter are the most critical.
If I did get into the distribution side, I could just print the parts lists out, and ship them with the boards, along with a print out of the schematic, might save some work for folks. If someone wants to save a dollar or two, they'd be free to substitute lesser parts, or other sources, but a list could still be helpful.
I started down this road about 6 months ago, and was pretty lost, but kind of had some results, stumbling around on my own. Now I'm pretty excited about the project, as people on this forum, with a lot more technical knowledge than I, got onto a similar path. I'm willing to do what I can to help make it happen, if there is interest from others. If not, I'm happy with the way things are, and could do a one off on perfboard.
If I did get into the distribution side, I could just print the parts lists out, and ship them with the boards, along with a print out of the schematic, might save some work for folks. If someone wants to save a dollar or two, they'd be free to substitute lesser parts, or other sources, but a list could still be helpful.
I started down this road about 6 months ago, and was pretty lost, but kind of had some results, stumbling around on my own. Now I'm pretty excited about the project, as people on this forum, with a lot more technical knowledge than I, got onto a similar path. I'm willing to do what I can to help make it happen, if there is interest from others. If not, I'm happy with the way things are, and could do a one off on perfboard.
Hi Guys
Guess what I did??? I finished the 3 phase splitter ( Hans Splitter Deluxe) and then it dawn on me this is fixed on 120/240 degree split. That is fine for the motors I am going to get and try. But the Hurst motors I have in pods now are 2 phase 90 degree split motors.
Well I will throw together post 151 two phase style have enough parts and a +/- 15 volt power supply for the op amp.
Anyone found a good source for a 3 phase motor???
Tom
Guess what I did??? I finished the 3 phase splitter ( Hans Splitter Deluxe) and then it dawn on me this is fixed on 120/240 degree split. That is fine for the motors I am going to get and try. But the Hurst motors I have in pods now are 2 phase 90 degree split motors.
Well I will throw together post 151 two phase style have enough parts and a +/- 15 volt power supply for the op amp.
Anyone found a good source for a 3 phase motor???
Tom
Tom did you get my private message? Also check this out: For all people looking for a 2 phase solution. I just found an English language manual for this 2 channel signal generator (model MHS 2300). I have attached a PDF of it to this post. I don't think any splitter would be necessary for 2 phase motors. It also has an ultra low range 0-600hz with 10 microhertz accuracy, and adjustments, memory features, and way more. I'm not much with digital technology, but the 10 bit wave accuracy, and 1024 point waveform length, seems better than others I've seen as well. Looks like you can pick one up on ebay for $67.99 on ebay.
BTW Tom, I'm looking for a 3 phase motor for you. I have a lead, and will get in touch with you via private message on this. Better yet we should be in touch via our private emails, I'll private message an email address to you, and you can reply, so I can have yours.
Hans, I'm not exactly sure what ramifications this generator would have for us that need a 3 phase solution. I'm thinking at the very least it would be way more accurate than previous generators, and if nothing else, I can program one channel for 60 hz, and the other for 81 hz, dial them in, and save the parameters. That way, I could change speeds by just changing channels. With your automatic frequency switch, and the post 179 3 phase schematic, coupled to this generator, might be the way to go.
twystd
BTW Tom, I'm looking for a 3 phase motor for you. I have a lead, and will get in touch with you via private message on this. Better yet we should be in touch via our private emails, I'll private message an email address to you, and you can reply, so I can have yours.
Hans, I'm not exactly sure what ramifications this generator would have for us that need a 3 phase solution. I'm thinking at the very least it would be way more accurate than previous generators, and if nothing else, I can program one channel for 60 hz, and the other for 81 hz, dial them in, and save the parameters. That way, I could change speeds by just changing channels. With your automatic frequency switch, and the post 179 3 phase schematic, coupled to this generator, might be the way to go.
twystd
Hi Tom, this is the one that Huns commented to my inquiry last week and I purchased one from NJ. Hope it will serve my 2 phase Hurst. This one is even more fancy...
Look at this on eBay
2MHz Dual Channel Signal Generator 200MSa/s 100MHz Frequency Arbitrary Waveform
Sent from my iPhone using Tapatalk
Look at this on eBay
2MHz Dual Channel Signal Generator 200MSa/s 100MHz Frequency Arbitrary Waveform
Sent from my iPhone using Tapatalk
Hi Tom, this is the one that Huns commented to my inquiry last week and I purchased one from NJ. Hope it will serve my 2 phase Hurst. This one is even more fancy...
Look at this on eBay
2MHz Dual Channel Signal Generator 200MSa/s 100MHz Frequency Arbitrary Waveform
Sent from my iPhone using Tapatalk
This one also says it 12 bit, the pdf manual for the other one says 10 bit. If true, this one is more than fancy 🙂
More pricy too...🙁. I'll see how MHS is doing. I'll get this FY if MHS will fail as my fist generator: HS380.
Just piece of gunk.
Sent from my iPhone using Tapatalk
Just piece of gunk.
Sent from my iPhone using Tapatalk
If it does what it says, it sounds like a bargain ($80). Would be useful for other tasks too.
Did you notice this in the ebay description
"Can choose our FYV2000 series or FPA1000 series power amplifier to output 20W~60W signal in DC-3MHz"
When using a two phase generator, you won't need a frequency switch.
All you need is this.
When changing the frequency from 60Hz to 81Hz, this circuit will keep the 0-12-240 degrees shift intact,
The two signals from the generator will have to be specified with a DC offset voltage, roughly equal to Vbias. This will prevent the need of inserting caps in the input lines, causing phase shift and amplitude shift.
Hans
I ordered the 12bit function generator for $75. If it arrives before I'm ready, I'm willing to send it to one of you for evaluation.