looking Function Generator project  - Page 1
Forum section: electronics / beginners

author: peps1
author_rank: Regular Contributor
timestamp: April 17, 2013, 02:31:15 pm
content: Hello guys,Just go my first oscilloscope, so looking to get a Function Generator next.......but would like to build one as a projectnot having used one before it hard to know what features I should be looking forso, hope someone can point me in the right direction!90% of my electronics work is analog audio, but I am getting more interested in digital logic and switching.

author: ddavidebor
author_rank: Super Contributor
timestamp: April 17, 2013, 02:37:45 pm
content: Sine, square, triangle... Zero to a couple of Mhz is cheap and great

author: peps1
author_rank: Regular Contributor
timestamp: April 17, 2013, 06:30:12 pm
content: thanks mate!Anyone got a link to a suitable project with PCB artwork?

author: ddavidebor
author_rank: Super Contributor
timestamp: April 17, 2013, 06:36:27 pm
content: well, i suggest you to buy something used. it's not like a power supply that you can build of good quality.you can buy a good function gen with 60€

author: Unknown
author_rank: Unknown
timestamp: April 17, 2013, 08:29:03 pm
content: See circuit below for a function generator 1Htz to 20Mhz, this was found on the web some time back; you would need to source the Max chip, and do a PCB lay-out...

author: Unknown
author_rank: Unknown
timestamp: April 17, 2013, 09:24:40 pm
content: The MAX038 was discontinued by Maxim quite a few years ago (I think it was around the time they switched all their processes to RoHS and discontinued the process used for the '038). It may still be available from shady eBay sellers. Expect it to be expensive ($20 or so), and the usual risk of buying from random Chinese sellers (could be desoldered or fake).This is too bad, since it was much better than the lousy XR2206.

author: MacAttak
author_rank: Unknown
timestamp: April 17, 2013, 10:16:12 pm
content: Interesting engineer name on that schematic.

author: BillyD
author_rank: Regular Contributor
timestamp: April 17, 2013, 10:16:54 pm
content: Variable duty cycle or PWM (for square waves) is another useful feature.I have one of these, not very pretty but cheap and functional :http://www.ebay.co.uk/itm/DDS-Sweep-Function-Signal-Generator-Wave-Meter-New-5MHz-/290677832126

author: c4757p
author_rank: Super Contributor
timestamp: April 17, 2013, 10:20:28 pm
content: Quote from: MacAttak on April 17, 2013, 10:16:12 pmI knew it looked familiar!20MHz High Speed Function Generator

author: notsob
author_rank: Frequent Contributor
timestamp: April 17, 2013, 10:28:12 pm
content: I wouldn't bother making one with the units available from Rigol, but if you must, you can get the MAX038 from futurlec for ~$23http://futurlec.com/ICMaxim.shtmlOther MAX038 circuits are Dick Cappels versionhttp://cappels.org/dproj/functsweep/functionswp.htmland Georgio's versionhttp://www.pcbheaven.com/projectpages/High_Frequency_Function_Generator/CheersPeter

author: Resistoid
author_rank: Contributor
timestamp: April 17, 2013, 11:12:09 pm
content: Peps1, if you want to buy a MAX038 in the UK you might try here:http://www.ebay.co.uk/itm/MAX038CPP-High-Frequency-Waveform-Generator-MAX038-/180860239105I have not used this source, hence I am unable to make a more substantive recommendation.Resistoid.

author: peps1
author_rank: Regular Contributor
timestamp: April 18, 2013, 10:49:10 am
content: Quote from: c4757p on April 17, 2013, 10:20:28 pmJust what im looking for......but sems to be missing a component layoutQuote from: Resistoid on April 17, 2013, 11:12:09 pmThanks mate!

author: Rerouter
author_rank: Super Contributor
timestamp: April 18, 2013, 10:54:45 am
content: its not missing one, you will have to lay it out if you want it, a large number of designs on the net are only published as schematics as then they can be adapted loosely into whatever it is your making,

author: peps1
author_rank: Regular Contributor
timestamp: April 18, 2013, 11:07:19 am
content: Quote from: Rerouter on April 18, 2013, 10:54:45 amthat seems to be the very definition of "missing".......Not present; absent.

author: c4757p
author_rank: Super Contributor
timestamp: April 18, 2013, 11:47:14 am
content: Dude, the link for the layout is right under the link for the schematic.

author: peps1
author_rank: Regular Contributor
timestamp: April 18, 2013, 12:47:46 pm
content: Quote from: c4757p on April 18, 2013, 11:47:14 amDude, I don't see it!?!?!?!Just link for the schematic and PCB....no component layout?Am I going blind?

author: c4757p
author_rank: Super Contributor
timestamp: April 18, 2013, 12:54:22 pm
content: Oops, I thought they'd be labelled on the PCB in the absence of a separate layout chart. Sorry. Yeah, I don't see one either. Still, it's a simple enough circuit, you could work it out pretty quickly from the schematic and PCB.

author: Resistoid
author_rank: Contributor
timestamp: April 18, 2013, 02:09:04 pm
content: @ peps1: You're welcome.

author: Unknown
author_rank: Unknown
timestamp: April 18, 2013, 10:45:39 pm
content: Nice to see members have good memories, I just did-not want to say where it came from, hope it's okay Dave.

author: Ferroto
author_rank: Frequent Contributor
timestamp: April 19, 2013, 07:12:07 pm
content: http://www.amazon.com/Function-Generator/dp/B00507BUOI/ref=pd_sim_sbs_indust_9