On Sat, 15 Dec 2012 06:15:05 +1000, "David Eather" <eather@tpg.com.au> wrote:>sorry not currently in stockAs others have noted, ebay has lots of them, mostly from Chinese suppliers. Some have good feedback, so I guess I'll use them. Or, it might be fun to do a triangle oscillator and sine shaper out of parts. Soft-clipping a triangle should be close enough. -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
are all the function generators gone?
Started by ●December 12, 2012
Reply by ●December 14, 20122012-12-14
Reply by ●December 14, 20122012-12-14
On Fri, 14 Dec 2012 13:05:46 -0800, John Larkin <jlarkin@highlandtechnology.com> wrote:>On Sat, 15 Dec 2012 06:15:05 +1000, "David Eather" <eather@tpg.com.au> >wrote: > >>sorry not currently in stock > >As others have noted, ebay has lots of them, mostly from Chinese >suppliers. Some have good feedback, so I guess I'll use them. > >Or, it might be fun to do a triangle oscillator and sine shaper out of >parts. Soft-clipping a triangle should be close enough.Isn't there a way to generate a sine wave using a Johnson counter and a resistor network? Ah, check out US4368432 (expired) .. the 4018 chips are still available.
Reply by ●December 14, 20122012-12-14
"Spehro Pefhany" wrote in message=20 news:107nc8tis31922p71pcfics5ubo559l1eu@4ax.com...> Isn't there a way to generate a sine wave using a Johnson counter > and a resistor network?> Ah, check out US4368432 (expired) .. the 4018 chips are still > available.Much easier, cheaper, and more flexible to use a PIC and a DAC. http://www.mouser.com/ProductDetail/Microchip-Technology/PIC12LF1822-I-SN= /?qs=3DsGAEpiMZZMsrb0xF%2fYczN1BcC%2f18WRbOaaXsdrqok7c%3d=20 ($1.00) http://www.mouser.com/ProductDetail/Microchip-Technology/MCP4921-E-SN/?qs= =3DsGAEpiMZZMswix2y39yldZi8VMiqnm0Zf0J%252bc0lSlGY%3d=20 ($2.00) You can store the sine table in the PIC, and sequence through it at any=20 frequency by using the clock (internal or crystal) and a built-in=20 programmable counter. Easy to synchronize phase. You can also select=20 triangle, square, or any arbitrary waveform you like. Paul=20
Reply by ●December 14, 20122012-12-14
On Fri, 14 Dec 2012 16:44:00 -0500, Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote:>On Fri, 14 Dec 2012 13:05:46 -0800, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Sat, 15 Dec 2012 06:15:05 +1000, "David Eather" <eather@tpg.com.au> >>wrote: >> >>>sorry not currently in stock >> >>As others have noted, ebay has lots of them, mostly from Chinese >>suppliers. Some have good feedback, so I guess I'll use them. >> >>Or, it might be fun to do a triangle oscillator and sine shaper out of >>parts. Soft-clipping a triangle should be close enough. > >Isn't there a way to generate a sine wave using a Johnson counter and >a resistor network? > >Ah, check out US4368432 (expired) .. the 4018 chips are still >available.That should work. I'd switch the clock frequency to make FSK. It should be adequately phase coherent. -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Reply by ●December 14, 20122012-12-14
On Fri, 14 Dec 2012 18:20:55 -0500, the renowned "P E Schoen" <paul@peschoen.com> wrote:>"Spehro Pefhany" wrote in message >news:107nc8tis31922p71pcfics5ubo559l1eu@4ax.com... > >> Isn't there a way to generate a sine wave using a Johnson counter >> and a resistor network? > >> Ah, check out US4368432 (expired) .. the 4018 chips are still >> available. > >Much easier, cheaper, and more flexible to use a PIC and a DAC. > >http://www.mouser.com/ProductDetail/Microchip-Technology/PIC12LF1822-I-SN/?qs=sGAEpiMZZMsrb0xF%2fYczN1BcC%2f18WRbOaaXsdrqok7c%3d >($1.00) > >http://www.mouser.com/ProductDetail/Microchip-Technology/MCP4921-E-SN/?qs=sGAEpiMZZMswix2y39yldZi8VMiqnm0Zf0J%252bc0lSlGY%3d >($2.00) > >You can store the sine table in the PIC, and sequence through it at any >frequency by using the clock (internal or crystal) and a built-in >programmable counter. Easy to synchronize phase. You can also select >triangle, square, or any arbitrary waveform you like. > >PaulIf I was going to go and write code, I'd probably spec something more like the ATXMEGA164A4U-MH, which is $1.80 in 25's and has two 12-bit DACs on board, as well as a dozen 12-bit ADC inputs to read the trimpots. Being an agnostic architecture-wise can pay off. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Reply by ●December 14, 20122012-12-14
"P E Schoen" <paul@peschoen.com> wrote:>"Spehro Pefhany" wrote in message=20 >news:107nc8tis31922p71pcfics5ubo559l1eu@4ax.com... > >> Isn't there a way to generate a sine wave using a Johnson counter >> and a resistor network? > >> Ah, check out US4368432 (expired) .. the 4018 chips are still >> available. > >Much easier, cheaper, and more flexible to use a PIC and a DAC.That is two components from which one is programmable. When using a controller I'd go for PWM and skip the DAC. But then again, a 'discrete' solution might be much simpler. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
Reply by ●December 14, 20122012-12-14
On Fri, 14 Dec 2012 16:44:00 -0500, Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote:>On Fri, 14 Dec 2012 13:05:46 -0800, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Sat, 15 Dec 2012 06:15:05 +1000, "David Eather" <eather@tpg.com.au> >>wrote: >> >>>sorry not currently in stock >> >>As others have noted, ebay has lots of them, mostly from Chinese >>suppliers. Some have good feedback, so I guess I'll use them. >> >>Or, it might be fun to do a triangle oscillator and sine shaper out of >>parts. Soft-clipping a triangle should be close enough. > >Isn't there a way to generate a sine wave using a Johnson counter and >a resistor network?Yep. I've even been known to create Gaussian rising and falling edges that way to keep digital modulation schemes clean... as in WiFi.> >Ah, check out US4368432 (expired) .. the 4018 chips are still >available....Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●December 14, 20122012-12-14
On Dec 14, 4:44=A0pm, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat> wrote:> On Fri, 14 Dec 2012 13:05:46 -0800, John Larkin > > <jlar...@highlandtechnology.com> wrote: > >On Sat, 15 Dec 2012 06:15:05 +1000, "David Eather" <eat...@tpg.com.au> > >wrote: > > >>sorry not currently in stock > > >As others have noted, ebay has lots of them, mostly from Chinese > >suppliers. Some have good feedback, so I guess I'll use them. > > >Or, it might be fun to do a triangle oscillator and sine shaper out of > >parts. Soft-clipping a triangle should be close enough. > > Isn't there a way to generate a sine wave using a Johnson counter and > a resistor network? > > Ah, check out US4368432 (expired) .. the 4018 chips are still > available.That's neat, Just remember to factor in the 4018 output impedance. George H.
Reply by ●December 14, 20122012-12-14
"Spehro Pefhany" wrote in message=20 news:fjfnc8tva54iv0fvl1g7cfg8mk70dk59m9@4ax.com...> If I was going to go and write code, I'd probably spec something more > like the ATXMEGA164A4U-MH, which is $1.80 in 25's and has two > 12-bit DACs on board, as well as a dozen 12-bit ADC inputs to read > the trimpots. Being an agnostic architecture-wise can pay off.Microchip now has a PIC with a DAC (8 bit) on-board: http://www.mouser.com/ProductDetail/Microchip-Technology/PIC16F1783-I-SS/= ?qs=3DsGAEpiMZZMutXGli8Ay4kCSh8yJiBQSBw2xhJraXXiw%3d=20 ($1.64/25) It also has two switch mode controllers, two op-amps, 3 comparators, and = voltage reference. And it has five fully differential 12 bit ADCs. I'd=20 rather stay with what I'm familiar with. There is almost no reason anymore to design something using discrete=20 components and basic logic ICs. Paul=20
Reply by ●December 14, 20122012-12-14
On Fri, 14 Dec 2012 20:48:42 -0500, the renowned "P E Schoen" <paul@peschoen.com> wrote:>"Spehro Pefhany" wrote in message >news:fjfnc8tva54iv0fvl1g7cfg8mk70dk59m9@4ax.com... > >> If I was going to go and write code, I'd probably spec something more >> like the ATXMEGA164A4U-MH, which is $1.80 in 25's and has two >> 12-bit DACs on board, as well as a dozen 12-bit ADC inputs to read >> the trimpots. Being an agnostic architecture-wise can pay off. > >Microchip now has a PIC with a DAC (8 bit) on-board: >http://www.mouser.com/ProductDetail/Microchip-Technology/PIC16F1783-I-SS/?qs=sGAEpiMZZMutXGli8Ay4kCSh8yJiBQSBw2xhJraXXiw%3d >($1.64/25)The DAC looks like a derivative of their older crude 5-bit DAC-- in fact with (unfortunately) typical uChip datasheet attention to detail, they've copied and pasted parts of Figure 19.1 so it shows a 256-resistor ladder feeding into a 32:1 mux.>It also has two switch mode controllers, two op-amps, 3 comparators, and >voltage reference. And it has five fully differential 12 bit ADCs.One ADC with an option to have 5 differential inputs or 11 single-ended. There are applications where we need actual multiple ADCs.>I'd rather stay with what I'm familiar with.There's less reason to do that with most of us using 'C' these days, but my impression is that Atmel is a bit spotty on long-term availability etc. for small scale customers. As typical with newer stuff, that uChip part has some fairly significant errata, much of it relating to the analog-y stuff (but not the DAC) http://ww1.microchip.com/downloads/en/DeviceDoc/80541C.pdf Some of the stuff they don't get around to fixing for years..>There is almost no reason anymore to design something using discrete >components and basic logic ICs. > >PaulNot big boards filled with logic, but tossing a few logic chips at part of a problem is often a decent way to go, especially with single and dual gate tiny packages. Micros are only one arrow in the quiver. Microchip's Configurable Logic Cells are interesting- incorporating a few gates or even a logic-level 555-equivalant onto the chip, though I've not yet had occasion to use that functionality. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
