cheap thrills signal generator
ragnar, Sat Nov 04 2006, 11:09AMSo that I no longer have to get annoyed with a loose oscillator chip being dragged around on its back by alligator leads, I rigidified it. You can adjust the pots without a screwdriver now, too. ^^
Screws, nuts, spacers and hardware are from my "mixed hardware bits" box.
Heatsink, regulator, diode and cable are from my "dead monitors" heap.
Potentiometers and sockets are from my "mixed ex-audio crap" tray.
Board and chips are from my "dead & superseded TC drivers" collection.
Acrylic was cut from offcuts in my 25W CO2 lasercutter. =-)
It swings from ~2MHz to ~22MHz before the squarewave gets too ugly.
Cheap thrills. Wee.
Re: cheap thrills signal generator
Marko, Sat Nov 04 2006, 11:24AM
Here's my version I made years ago.
I had big trouble finding proper oscillator, I tought simple logic gates would be best approach but signal detoriated very quickly. (and duty cycle was fixed).
So I just rated it 1Mhz and stuffed in powerful push-pull stage so I can drive something.
Electronics are subject to changes but it served me well most of time.
If I come into need I'l probably build some more serious waveform generator, although I didn't really need much better than this!
(very old pics, hope you don't mind)
Marko, Sat Nov 04 2006, 11:24AM
Here's my version I made years ago.
I had big trouble finding proper oscillator, I tought simple logic gates would be best approach but signal detoriated very quickly. (and duty cycle was fixed).
So I just rated it 1Mhz and stuffed in powerful push-pull stage so I can drive something.
Electronics are subject to changes but it served me well most of time.
If I come into need I'l probably build some more serious waveform generator, although I didn't really need much better than this!
(very old pics, hope you don't mind)
Re: cheap thrills signal generator
Avalanche, Sat Nov 04 2006, 11:29AM
Nice! I need to build a new one of these, quite handy things to have around. The last one I built was a 5 minute job and I somehow blew it up on the first use
Avalanche, Sat Nov 04 2006, 11:29AM
Nice! I need to build a new one of these, quite handy things to have around. The last one I built was a 5 minute job and I somehow blew it up on the first use
Re: cheap thrills signal generator
Self Defenestrate, Sat Nov 04 2006, 05:17PM
Hey, Balsamplack, would you mind elaborating a bit on how that thing works? I wouldn't mind building one myself..
Self Defenestrate, Sat Nov 04 2006, 05:17PM
Hey, Balsamplack, would you mind elaborating a bit on how that thing works? I wouldn't mind building one myself..
Re: cheap thrills signal generator
..., Sat Nov 04 2006, 06:18PM
He cheated and used a max038 to do the signal generating. Unfortunantly they are about as hard to find as left handed bacon stretcher these days (the plant that they were made at is no longer owned my maxim)
Looks good in any case!
I want to make something like this, and since I do have a max038, it shouldn't be very much work... I just want to find a way to really protect the chip (I am considering feeding it into a little telecom laser I have, and fiber coupling it
should be good to ~10ghz) Some day...
..., Sat Nov 04 2006, 06:18PM
He cheated and used a max038 to do the signal generating. Unfortunantly they are about as hard to find as left handed bacon stretcher these days (the plant that they were made at is no longer owned my maxim)
Looks good in any case!
I want to make something like this, and since I do have a max038, it shouldn't be very much work... I just want to find a way to really protect the chip (I am considering feeding it into a little telecom laser I have, and fiber coupling it
should be good to ~10ghz) Some day...Re: cheap thrills signal generator
Marko, Sat Nov 04 2006, 10:07PM
My plan would be getting HC version of 4049 chip (18Mhz) used with 89C2051 mcu, as a precise software-controlled frequency syntesizer.
Simple logic multivibrators don't work as well as I tought - they are simply ''too weak'' to push sharp square edges well into output capacitances, so I need to find a powerful output driver to get a decent signal (these are hopes for that grey-box generator).
Marko, Sat Nov 04 2006, 10:07PM
My plan would be getting HC version of 4049 chip (18Mhz) used with 89C2051 mcu, as a precise software-controlled frequency syntesizer.
Simple logic multivibrators don't work as well as I tought - they are simply ''too weak'' to push sharp square edges well into output capacitances, so I need to find a powerful output driver to get a decent signal (these are hopes for that grey-box generator).
Re: cheap thrills signal generator
ragnar, Sat Nov 04 2006, 10:16PM
Hey, no cheating here! That's a $0.45 74HC4046 =-)
The output of the 4046 is buffered with a single UCC37322, very simple :)
ragnar, Sat Nov 04 2006, 10:16PM
Hey, no cheating here! That's a $0.45 74HC4046 =-)
The output of the 4046 is buffered with a single UCC37322, very simple :)
Re: cheap thrills signal generator
Marko, Sat Nov 04 2006, 10:21PM
Yeah, UCC is probably a best driver you can find around although I doubt it would give good square even when weakly loaded.
Sometimes it may be worth to afford something faster from DEI for such use...
''Dad, I want a CNC CO2 laser!''
Marko, Sat Nov 04 2006, 10:21PM
Yeah, UCC is probably a best driver you can find around although I doubt it would give good square even when weakly loaded.
Sometimes it may be worth to afford something faster from DEI for such use...
''Dad, I want a CNC CO2 laser!''
Re: cheap thrills signal generator
Hazmatt_(The Underdog), Sat Nov 04 2006, 11:13PM
All you're missing is the frequency counter, and you have a lab grade generator ^^
Hazmatt_(The Underdog), Sat Nov 04 2006, 11:13PM
All you're missing is the frequency counter, and you have a lab grade generator ^^
Re: cheap thrills signal generator
ragnar, Sat Nov 04 2006, 11:47PM
I love the frequency counter, Hazmatt -- that was the first thing on my mind when I was building this, but I think I'll have to make do with my frequency-counting mulimeter for now.
Quit making snide remarks about my apparent wealth, already.
hehe
ragnar, Sat Nov 04 2006, 11:47PM
I love the frequency counter, Hazmatt -- that was the first thing on my mind when I was building this, but I think I'll have to make do with my frequency-counting mulimeter for now.
Firkragg wrote ...
Sometimes it may be worth to afford something faster from DEI for such use...
''Dad, I want a CNC CO2 laser!''
Sometimes it may be worth to afford something faster from DEI for such use...
''Dad, I want a CNC CO2 laser!''
Quit making snide remarks about my apparent wealth, already.
heheRe: cheap thrills signal generator
Hazmatt_(The Underdog), Sun Nov 05 2006, 01:46AM
why?
you can build a frequency counter too. It's not that hard once you figure out how to do it.
Hazmatt_(The Underdog), Sun Nov 05 2006, 01:46AM
why?
you can build a frequency counter too. It's not that hard once you figure out how to do it.
Re: cheap thrills signal generator
Steve Conner, Sun Nov 05 2006, 11:47AM
Does yours work at 22MHz hazmatt?
As for how "good" a square wave something gives at these frequencies, remember that a 20MHz or even a 40MHz or 60MHz scope isn't going to give an accurate picture of what a 22MHZ square wave really looks like. We have a 400MHz analog scope in our lab at work, and if you prod a digital circuit with it, the waveforms look shockingly different to what you get with a regular scope. Not usually in a nice way!
*edit* I forgot the bit about modslapping Firkragg and BP into the middle of next week if they don't quit arguing about whose parents can or can't afford laser cutters.
Steve Conner, Sun Nov 05 2006, 11:47AM
Does yours work at 22MHz hazmatt?
As for how "good" a square wave something gives at these frequencies, remember that a 20MHz or even a 40MHz or 60MHz scope isn't going to give an accurate picture of what a 22MHZ square wave really looks like. We have a 400MHz analog scope in our lab at work, and if you prod a digital circuit with it, the waveforms look shockingly different to what you get with a regular scope. Not usually in a nice way!
*edit* I forgot the bit about modslapping Firkragg and BP into the middle of next week if they don't quit arguing about whose parents can or can't afford laser cutters.
Re: cheap thrills signal generator
Marko, Sun Nov 05 2006, 01:25PM
'regular' probes can own few hundred pf of capacitance as minimum, and this detoriates squarewave at such frequncies.
Maybe we could use just a small pece of coax cable with BNC connected directly to scope to minimize the capacitance for squarewave measuring (messy but may be useful sometimes).
Hey, I actually wanted to say that his CNC cutter is cool (including acrylic stuff cut with it).
Didn't want you to think I'm all in jealousy or something and my emotions are leading me into evil. ^^ :)
Marko, Sun Nov 05 2006, 01:25PM
'regular' probes can own few hundred pf of capacitance as minimum, and this detoriates squarewave at such frequncies.
Maybe we could use just a small pece of coax cable with BNC connected directly to scope to minimize the capacitance for squarewave measuring (messy but may be useful sometimes).
*edit* I forgot the bit about modslapping Firkragg and BP into the middle of next week if they don't quit arguing about whose parents can or can't afford laser cutters.
Hey, I actually wanted to say that his CNC cutter is cool
(including acrylic stuff cut with it).Didn't want you to think I'm all in jealousy or something and my emotions are leading me into evil. ^^ :)
Re: cheap thrills signal generator
Hazmatt_(The Underdog), Sun Nov 05 2006, 07:11PM
Steve, the chips can handle 40MHz without a prescaler
And I can count as high as I want, provided I have enough digits
My counter works great up to 100Hz standard timebase input. After that, reading the digits becomes a bit difficult. But with 100Hz, 8 digits, and a prescaler option, you have a sweet and simple versatile counter.
If you guys want, I can post details once im done with my DSP and Physics tedium.
Hazmatt_(The Underdog), Sun Nov 05 2006, 07:11PM
Steve, the chips can handle 40MHz without a prescaler
And I can count as high as I want, provided I have enough digits
My counter works great up to 100Hz standard timebase input. After that, reading the digits becomes a bit difficult. But with 100Hz, 8 digits, and a prescaler option, you have a sweet and simple versatile counter.
If you guys want, I can post details once im done with my DSP and Physics tedium.
Re: cheap thrills signal generator
Part Scavenger, Mon Nov 06 2006, 12:59PM
That's nice BP! I started building one about two months ago, and so far the boards are just sitting there. All that's left is Assy, I even made a nice box out of aluminum.
School. Pbbt.
Part Scavenger, Mon Nov 06 2006, 12:59PM
That's nice BP! I started building one about two months ago, and so far the boards are just sitting there. All that's left is Assy, I even made a nice box out of aluminum.
School. Pbbt.
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