EMRFD Message Archive 11764
Message Date From Subject 11764 2015-10-12 09:16:53 lawrence_joy Function Generator Has anyone duplicated or attempted to build "A Simple yet Precise Function Generator for the Experimenter" by Rubens Fernandes, VK5FE, that appeared in the 2013-05/06 issue of QEX? Or should I look in my 2015 ARRL Handbook or online for something else? Comments?
73 de 9V1MI/WN8P, Larry
11765 2015-10-12 10:28:54 David J Nushardt Re: Function Generator
Dave N9OOQ
Sent from my Kindle fire HDX 8.911768 2015-10-12 12:00:09 Jim Strohm Re: Function Generator
7311769 2015-10-12 13:11:41 Rod Re: Function Generator
This may be of interest to you:
https://www.sparkfun.com/products/11420
Also, Using a resistor R2R network (available from Digikey) , one can do
arbitrary
waveform generation with 8 bit D/A resolution. I found an article online
(don't have
an immediate reference- try googling) with open source software, and it
has been on my to-do list.
Rod KM6SN11775 2015-10-13 07:03:21 lawrence_joy Re: Function Generator Rod, I looked at that Sparkfun project before when I was looking around. It does go to 3 MHz but the output has a dc offset of Vcc/2 and the output amplitude is 1 V pp. Neither of these parameters is adjustable or variable. I suppose I could add external circuitry, but I don't want to dink with it at this time.
I generally don't find what I am looking for when doing Internet searches. I either put too much information in, not enough, not in the proper order, or not the right words. So, if you find the article of "arbitrary waveform generation with 8 bit D/A resolution with open source software" please let me know. I can be reached at the e-mail address given
11780 2015-10-14 15:27:05 kerrypwr Re: Function Generator
Although obsolete they seem to be readily available at low cost.
Maximum frequency is about 200kHz or about 20kHz with only moderate distortion; I think that that is about right for a function generator which is not a true RF signal generator.
The data sheet (go to http://www.intersil.com) and search for 8038) contains suggested circuits and there are many on the 'net; this one, picked at random, looks useful.
http://electronics-diy.com/electronic_schematic.php?id=112Kerry VK2TIL.
11781 2015-10-14 21:57:33 arfghans Re: Function Generator 11782 2015-10-15 08:55:30 Riccardo Montagut... Re: Function Generator
Riccardo
Inviato da iPhoneI'll put in another vote for the 8038 as a basic function generator. Very easy to apply. Just add range switching and an output amp/attenuator. THD is ok for anything but critical distortion measurements. I built such an instrument while in high school in the 70s and it served me well for decades. No computer required :-)
By the way, that chip was designed by the great Hans Camenzind, the guy who also brought us the 555.Gary, NA6O
11785 2015-10-15 12:54:38 Todd F. Carney / ... Re: Function Generator 11786 2015-10-15 13:00:22 Dana Myers Re: Function Generator 11842 2015-10-24 10:05:23 lawrence_joy Re: Function Generator 11843 2015-10-24 20:16:18 David J Nushardt Re: Function Generator Sounds good, along the lines of the classic wein bridge design ,I saw a article in a book by a famous analog design engineer , who is no longer with us , but his books and application notes so are, forgive me I'm blanking on his name, he worked for Linear Technologies.
He designed a modern ultra low distortion version of the classic hp wein bridge oscillator,as I recall the parts will run about 60- 80 bucks but it's ultra low distortion, its quite a project.
I believe the diagram is on the web in pdf. For free, you will have to do some searching for it.Sorry my brain is not cooperating, I had two strokes and cml leukemia, maybe someone can help me with the name Jim comes to mind, and the book the article is from, both the designer and the circuit is famous. Can someone help me, to recall this, Jim Williams is his name just clicked in but he has several not so cheap analog design books , I'm still having trouble recalling the book I seen this moder version of the classic hp wein bridge Oscillator in.
73's best of luck.
Dave
Sent from my Kindle fire HDX 8.911844 2015-10-24 20:31:28 n2msqrp Re: Function Generator
You are correct. Jim Williams was an Application Engineer for Linear Devices. Here is information about his book:
<http://www.linear.com/designtools/acd_book.php>
Ironically, Jim did not bother getting and Engineering degree but worked in the MIT Instrumentation Lab to learn his trade.
I first learned about him when he wrote an excellent series of articles about temperature measurements in EDN magaine in the 1970's.
I still have those articles stashed away in my file cabinet.
Mike N2MS
----- Original Message -----
11845 2015-10-24 22:06:58 David J Nushardt Re: Function Generator Yes, jim williams, but the books I'm talking about are the ones Amazon has he also wrote numerous application notes available on the web by searching for Jim Williams application notes, the actual article I'm talking about was a modern version of the hp 200C oscillator , I think, he scribbled a schematic using all LT parts and modern components , it was his version of the hp 200 c oscillator, using modern mostly available components, the only thing was a opto isolator that was a little difficult to find.
Thanks!
73's DaveSent from my Kindle fire HDX 8.9
11846 2015-10-24 22:17:12 David J Nushardt Re: Function Generator I found it, just google, Jim Williams version of the hp oscillator. Its a very interesting article.
DaveSent from my Kindle fire HDX 8.9