Now and again, one gets to bite the biter.
In this case, a character in Europe has been making a research instrument and touting it as the absolutely best that can possibly be made. It happens that I am the only competition on the planet, and make a significantly different instrument (which the USDA has finally approved the patent on).
The fun now is that I have on my workbench a recent European instrument to reverse engineer. I can't help but notice that a contact that is made external to the instrument is soldered with lead-free solder (RoHS, ya know). But inside, all them solder joints are tin-lead. He uses phenolic boards, so the pure tin would lift the traces.
To complete the silliness, the head amplifier that is placed close to the biological signals being collected, uses a CA3420 op amp, perhaps circa 1983. It is housed in a DB-25 shell - plastic with aluminum flash. The BNC jack fits the cable path. Contact is by tightening the nut to a light friction fit.
Inside, though, is the same crap used since 1985. Like a 741 op amp. And this clown claims to have the best stuff possible. The control for the applied substrate voltage is not even marked in a meaningful way. The schematic is strange. This is a hobbyist level instrument at best.
I see significant noise in the power supply - and in the output, as a 741 faithfully passes rail noise right out the output. He uses a overall gain of 100 and 8 bits conversion to do electrophysiology recordings. There is lots of noise in the baseline and drift is significant.
He has proposed an "ideal" AC instrument. Having made one, he dismisses it as totally insignificant as his did not produce a usable output. He seems to think the principle is similar to AM radio.
That's odd, as I have been producing such instruments for many years. With gains of 10,000 and a flat baseline using 14 bit conversions. Quite a number of papers are in print now that utterly disprove his contentions about his instrument. Now I get the satisfaction of demonstrating just how poorly made it is.
I feel better now.
In this case, a character in Europe has been making a research instrument and touting it as the absolutely best that can possibly be made. It happens that I am the only competition on the planet, and make a significantly different instrument (which the USDA has finally approved the patent on).
The fun now is that I have on my workbench a recent European instrument to reverse engineer. I can't help but notice that a contact that is made external to the instrument is soldered with lead-free solder (RoHS, ya know). But inside, all them solder joints are tin-lead. He uses phenolic boards, so the pure tin would lift the traces.
To complete the silliness, the head amplifier that is placed close to the biological signals being collected, uses a CA3420 op amp, perhaps circa 1983. It is housed in a DB-25 shell - plastic with aluminum flash. The BNC jack fits the cable path. Contact is by tightening the nut to a light friction fit.
Inside, though, is the same crap used since 1985. Like a 741 op amp. And this clown claims to have the best stuff possible. The control for the applied substrate voltage is not even marked in a meaningful way. The schematic is strange. This is a hobbyist level instrument at best.
I see significant noise in the power supply - and in the output, as a 741 faithfully passes rail noise right out the output. He uses a overall gain of 100 and 8 bits conversion to do electrophysiology recordings. There is lots of noise in the baseline and drift is significant.
He has proposed an "ideal" AC instrument. Having made one, he dismisses it as totally insignificant as his did not produce a usable output. He seems to think the principle is similar to AM radio.
That's odd, as I have been producing such instruments for many years. With gains of 10,000 and a flat baseline using 14 bit conversions. Quite a number of papers are in print now that utterly disprove his contentions about his instrument. Now I get the satisfaction of demonstrating just how poorly made it is.
I feel better now.
