On 11/18/2021 18:11, Phil Hobbs wrote:> Phil Hobbs wrote: >> Jan Panteltje wrote: >>> On a sunny day (Wed, 17 Nov 2021 20:19:54 -0800) it happened >>> jlarkin@highlandsniptechnology.com wrote in >>> <02lbpgt8a1m6t56vfnv8lcqpvnotmj7rhk@4ax.com>: >>> >>> Nice to have it all in that chip, but the modulation - demodulation >>> is always a bit .. Not Needed? I remember back in the seventies >>> using optocouplers for audio and a bit higher frequencies, there >>> was a chip for that too, no idea what the type number was. May >>> still have one somewhere, >>> >>> >> >> TI used to make the (iirc) TIL311, > > TIL300, it was. > >> which had a LED and two photodiodes, all mutually isolated. You used >> one PD to servo the LED brightness, and used the other one as the >> output. >> >> Cheers >> >> Phil Hobbs >> > >But it was TIL311 I remembered as something I had seen :-). Early 80-s I guess.
low cost isolation amplifier
Started by ●November 18, 2021
Reply by ●November 18, 20212021-11-18
Reply by ●November 18, 20212021-11-18
On 11/18/2021 7:28, jlarkin@highlandsniptechnology.com wrote:> On Thu, 18 Nov 2021 00:00:46 -0500, bitrex <user@example.net> wrote: > >> On 11/17/2021 11:19 PM, jlarkin@highlandsniptechnology.com wrote: >>> >>> https://www.mouser.com/ProductDetail/Texas-Instruments/ISO120SG?qs=rNOSrj6uCs17dA0jO5%2FyAw%3D%3D >>> >>> >>> >> >> They had to pay the burglars to snatch some out of the Smithsonian so >> they could put them back on the shelf > > But I really need a low cost isolation amplifier. > > Looks like roughly $3 each. SiLabs has a three channel isolated ADC > that is interesting, if I can figure out the actual throughput rate. > Si8902. >Depending on the throughput you need could you perhaps do some cheap ADC -> opto -> DAC scheme... I am not very familiar with the cheap side of MCU-s but I think there are very cheap ones with an ADC, not so sure about the DAC (those I use are precision, cost >$10, but may be there are cheaper). I suppose something like 10uS per word should be achievable but well, I am just musing.
Reply by ●November 18, 20212021-11-18
torsdag den 18. november 2021 kl. 08.00.46 UTC+1 skrev Phil Hobbs:> Jan Panteltje wrote: > > On a sunny day (Wed, 17 Nov 2021 20:19:54 -0800) it happened > > jla...@highlandsniptechnology.com wrote in > > <02lbpgt8a1m6t56vf...@4ax.com>: > > > > Nice to have it all in that chip, > > but the modulation - demodulation is always a bit .. Not Needed? > > I remember back in the seventies using optocouplers for audio and a bit higher > > frequencies, there was a chip for that too, no idea what the type number was. > > May still have one somewhere, > > > > > TI used to make the (iirc) TIL311, which had a LED and two photodiodes, > all mutually isolated. You used one PD to servo the LED brightness, and > used the other one as the output.or HCNR200, afair it pretty require calibration because the photodiodes are like +/-10% gain
Reply by ●November 18, 20212021-11-18
Dimiter_Popoff wrote:> On 11/18/2021 18:11, Phil Hobbs wrote: >> Phil Hobbs wrote: >>> Jan Panteltje wrote: >>>> On a sunny day (Wed, 17 Nov 2021 20:19:54 -0800) it happened >>>> jlarkin@highlandsniptechnology.com wrote in >>>> <02lbpgt8a1m6t56vfnv8lcqpvnotmj7rhk@4ax.com>: >>>> >>>> Nice to have it all in that chip, but the modulation - demodulation >>>> is always a bit .. Not Needed? I remember back in the seventies >>>> using optocouplers for audio and a bit higher frequencies, there >>>> was a chip for that too, no idea what the type number was. May >>>> still have one somewhere, >>>> >>>> >>> >>> TI used to make the (iirc) TIL311, >> >> TIL300, it was. >> >>> which had a LED and two photodiodes, all mutually isolated. You used >>> one PD to servo the LED brightness, and used the other one as the >>> output. >>> >>> Cheers >>> >>> Phil Hobbs >>> >> >> > > But it was TIL311 I remembered as something I had seen :-). Early 80-s > I guess.Me too. ;) The TIL331 is a seven-segment LED display. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●November 18, 20212021-11-18
On Thursday, November 18, 2021 at 8:11:22 AM UTC-8, Phil Hobbs wrote:> Phil Hobbs wrote:> > TI used to make the (iirc) TIL311, > TIL300, it was. > > which had a LED and two photodiodes, all mutually isolated. You used > > one PD to servo the LED brightness, and used the other one as the > > output.I'd consider using a dual isolator, with the LEDs in series, except that the usual pinouts don't physically separate the hot-side output from the cold one. It'd be OK for low-voltage floating, though. TIL300 matching (transfer gain) is tested, the -A version had max 10% mismatch, with 25% on the run-of-the-mill parts. That probably is a production nuisance.
Reply by ●November 18, 20212021-11-18
whit3rd wrote:> On Thursday, November 18, 2021 at 8:11:22 AM UTC-8, Phil Hobbs wrote: >> Phil Hobbs wrote: > >>> TI used to make the (iirc) TIL311, >> TIL300, it was. >>> which had a LED and two photodiodes, all mutually isolated. You used >>> one PD to servo the LED brightness, and used the other one as the >>> output. > > I'd consider using a dual isolator, with the LEDs in series, > except that the usual pinouts don't physically separate the > hot-side output from the cold one. It'd be OK for low-voltage floating, though. > > TIL300 matching (transfer gain) is tested, the -A version had max 10% mismatch, > with 25% on the run-of-the-mill parts. That probably is a production nuisance. >Well, the part is long gone anyway. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●November 18, 20212021-11-18
On 11/18/2021 12:02 PM, Dimiter_Popoff wrote:> On 11/18/2021 7:28, jlarkin@highlandsniptechnology.com wrote: >> On Thu, 18 Nov 2021 00:00:46 -0500, bitrex <user@example.net> wrote: >> >>> On 11/17/2021 11:19 PM, jlarkin@highlandsniptechnology.com wrote: >>>> >>>> https://www.mouser.com/ProductDetail/Texas-Instruments/ISO120SG?qs=rNOSrj6uCs17dA0jO5%2FyAw%3D%3D >>>> >>>> >>>> >>>> >>> >>> They had to pay the burglars to snatch some out of the Smithsonian so >>> they could put them back on the shelf >> >> But I really need a low cost isolation amplifier. >> >> Looks like roughly $3 each. SiLabs has a three channel isolated ADC >> that is interesting, if I can figure out the actual throughput rate. >> Si8902. >> > > Depending on the throughput you need could you perhaps do some cheap > ADC -> opto -> DAC scheme... I am not very familiar with the cheap side > of MCU-s but I think there are very cheap ones with an ADC, not so > sure about the DAC (those I use are precision, cost >$10, but may be > there are cheaper). I suppose something like 10uS per word should > be achievable but well, I am just musing. >There are I2C isolators with 2.5kV standoff voltages, at 400kHz signaling rate I think you should be able to get close to 60kHz 16 bit data across that with some basic lossless compression like modems use
Reply by ●November 18, 20212021-11-18
On 11/18/2021 1:38 PM, bitrex wrote:> On 11/18/2021 12:02 PM, Dimiter_Popoff wrote: >> On 11/18/2021 7:28, jlarkin@highlandsniptechnology.com wrote: >>> On Thu, 18 Nov 2021 00:00:46 -0500, bitrex <user@example.net> wrote: >>> >>>> On 11/17/2021 11:19 PM, jlarkin@highlandsniptechnology.com wrote: >>>>> >>>>> https://www.mouser.com/ProductDetail/Texas-Instruments/ISO120SG?qs=rNOSrj6uCs17dA0jO5%2FyAw%3D%3D >>>>> >>>>> >>>>> >>>>> >>>> >>>> They had to pay the burglars to snatch some out of the Smithsonian so >>>> they could put them back on the shelf >>> >>> But I really need a low cost isolation amplifier. >>> >>> Looks like roughly $3 each. SiLabs has a three channel isolated ADC >>> that is interesting, if I can figure out the actual throughput rate. >>> Si8902. >>> >> >> Depending on the throughput you need could you perhaps do some cheap >> ADC -> opto -> DAC scheme... I am not very familiar with the cheap side >> of MCU-s but I think there are very cheap ones with an ADC, not so >> sure about the DAC (those I use are precision, cost >$10, but may be >> there are cheaper). I suppose something like 10uS per word should >> be achievable but well, I am just musing. >> > > There are I2C isolators with 2.5kV standoff voltages, at 400kHz > signaling rate I think you should be able to get close to 60kHz 16 bit > data across that with some basic lossless compression like modems useIt would be interesting project to see how good you could do with the 10 bit internal ADC and some data compression on say a ATTiny85 on one side and another doing decompress and fast PWM DAC on the other with both 8-bitters just running flat-out at 20 MHz top speed
Reply by ●November 18, 20212021-11-18
torsdag den 18. november 2021 kl. 19.43.52 UTC+1 skrev bitrex:> On 11/18/2021 1:38 PM, bitrex wrote: > > On 11/18/2021 12:02 PM, Dimiter_Popoff wrote: > >> On 11/18/2021 7:28, jla...@highlandsniptechnology.com wrote: > >>> On Thu, 18 Nov 2021 00:00:46 -0500, bitrex <us...@example.net> wrote: > >>> > >>>> On 11/17/2021 11:19 PM, jla...@highlandsniptechnology.com wrote: > >>>>> > >>>>> https://www.mouser.com/ProductDetail/Texas-Instruments/ISO120SG?qs=rNOSrj6uCs17dA0jO5%2FyAw%3D%3D > >>>>> > >>>>> > >>>>> > >>>>> > >>>> > >>>> They had to pay the burglars to snatch some out of the Smithsonian so > >>>> they could put them back on the shelf > >>> > >>> But I really need a low cost isolation amplifier. > >>> > >>> Looks like roughly $3 each. SiLabs has a three channel isolated ADC > >>> that is interesting, if I can figure out the actual throughput rate. > >>> Si8902. > >>> > >> > >> Depending on the throughput you need could you perhaps do some cheap > >> ADC -> opto -> DAC scheme... I am not very familiar with the cheap side > >> of MCU-s but I think there are very cheap ones with an ADC, not so > >> sure about the DAC (those I use are precision, cost >$10, but may be > >> there are cheaper). I suppose something like 10uS per word should > >> be achievable but well, I am just musing. > >> > > > > There are I2C isolators with 2.5kV standoff voltages, at 400kHz > > signaling rate I think you should be able to get close to 60kHz 16 bit > > data across that with some basic lossless compression like modems use > It would be interesting project to see how good you could do with the 10 > bit internal ADC and some data compression on say a ATTiny85 on one side > and another doing decompress and fast PWM DAC on the other with both > 8-bitters just running flat-out at 20 MHz top speedAD have several isolated delta-sigma ADCs that would just need a clock and a lowpass filter on the "DAC" side
Reply by ●November 18, 20212021-11-18
On 11/18/2021 1:56 PM, Lasse Langwadt Christensen wrote:> torsdag den 18. november 2021 kl. 19.43.52 UTC+1 skrev bitrex: >> On 11/18/2021 1:38 PM, bitrex wrote: >>> On 11/18/2021 12:02 PM, Dimiter_Popoff wrote: >>>> On 11/18/2021 7:28, jla...@highlandsniptechnology.com wrote: >>>>> On Thu, 18 Nov 2021 00:00:46 -0500, bitrex <us...@example.net> wrote: >>>>> >>>>>> On 11/17/2021 11:19 PM, jla...@highlandsniptechnology.com wrote: >>>>>>> >>>>>>> https://www.mouser.com/ProductDetail/Texas-Instruments/ISO120SG?qs=rNOSrj6uCs17dA0jO5%2FyAw%3D%3D >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>>> They had to pay the burglars to snatch some out of the Smithsonian so >>>>>> they could put them back on the shelf >>>>> >>>>> But I really need a low cost isolation amplifier. >>>>> >>>>> Looks like roughly $3 each. SiLabs has a three channel isolated ADC >>>>> that is interesting, if I can figure out the actual throughput rate. >>>>> Si8902. >>>>> >>>> >>>> Depending on the throughput you need could you perhaps do some cheap >>>> ADC -> opto -> DAC scheme... I am not very familiar with the cheap side >>>> of MCU-s but I think there are very cheap ones with an ADC, not so >>>> sure about the DAC (those I use are precision, cost >$10, but may be >>>> there are cheaper). I suppose something like 10uS per word should >>>> be achievable but well, I am just musing. >>>> >>> >>> There are I2C isolators with 2.5kV standoff voltages, at 400kHz >>> signaling rate I think you should be able to get close to 60kHz 16 bit >>> data across that with some basic lossless compression like modems use >> It would be interesting project to see how good you could do with the 10 >> bit internal ADC and some data compression on say a ATTiny85 on one side >> and another doing decompress and fast PWM DAC on the other with both >> 8-bitters just running flat-out at 20 MHz top speed > > AD have several isolated delta-sigma ADCs that would just need a clock and a lowpass filter on the "DAC" side > >Is they available for love and/or money?
