What is a modern version of the TBA120? Preferably in a package visible to the naked eye.
Actually I just need the limiting amp part from 1kHz to 20 MHz, say 50 uV limiting in, couple of hundred mV limited out. Supply voltage not important. No noise.
can't use a video amp? You could put some nice low cap diodes in the feed back loop for limiting.
Jamie
On a sunny day (Sat, 09 Feb 2013 15:31:20 GMT) it happened Jan Panteltje wrote in :
detector,
endless.
Or better an electret mike and measure the time delay between the RF spark and the sound. I usually count, 3 seconds is a km. A fast PIC could do a bit of digital signal processing to get that low rumble, else some opamps..
detector,
are endless.
the sound.
Try that simplistic approach when the number of strikes is over 1100 in a half hour.
detector,
endless.
the sound.
Not trying to thread hijack here, but I've always wondered if the charge onn the plastic in an electret mic fades away over time, like an old magnet?
detector,
are endless.
and the sound.
Makes you wonder. Mylar like tapes for wrapping have a charge. I once made a Mylar tape electrostatic speaker.
Greg
detector,
are endless.
and the sound.
Magnets don't fade much. A little when they are young, but virtually none after that.
e
' detector,
ons are endless.
ark and the sound.
This generally useful paper on electret microphones:
says "charge potential has a predicted half-life of several decades"
but doesn't describe the mechanism by which it is lost.
detector,
are endless.
and the sound.
They why do they need to remagnetize the magneto on old huff & puff engines? I knew someone who made & sold hundreds of electromagnets for that job.
detector,
are endless.
and the sound.
Perhaps they got too warm? I dunno!
Iron and Alnico aren't stable the way ceramic and rare earth ones are. If you leave the keeper off an Alnico magnet long, it'll demagnetize itself.
Cheers
Phil Hobbs
detector,
are endless.
and the sound.
Gosh. I don't know. Maybe too much huff and not enough puff.
Are permanent magnets really permanent? Magnets generally retain their magnetism unless they are stored near power lines, other magnets, and high temperatures. Over time, magnet materials lose a very small amount of magnetism. For example, Samarium Cobalt magnets may lose about 1% of their magnetism in ten years.
detector,
variations are endless.
spark and the sound.
Do you think that type of magnet was available when they designed those first gasoline engines?
detector,
variations are endless.
spark and the sound.
Probably. I don't know. They may have compromised on the magnetic properties for mechanical reasons. I researched it pretty thoroughly when I was a loudspeaker contractor.
They looked like Alnico magnets, and would die in about 20-50 years. A speaker's magnetic circuit is nothing like a Magneto.
Huff & puff engines have been around for over 100 years, but Alnico was developed in the '30s so it was probably just a cast iron slug that was machined to have a smooth face.
A lie. Antique generator sets still run just fine, and they were fitted with AlNiCo magnets.
There were other magnet alloys before AlNiCo. It was probably NOT raw Iron.
By imposing an electric field via the electrodes while the dielectric is hot, and slowly cooling the electret material while maintaining the polarizing voltage.
See the section on Manufacture.
Joe Gwinn
If you need sinewave out, could a 4046 be used as clock for a DDS? Never tried it.
Or even better: add a low-pass, makes a sinewave, leave out that DDS.
If you need sinewave out, could a 4046 be used as clock for a DDS? Never tried it.
Or even better: add a low-pass, makes a sinewave, leave out that DDS.
And there is also some chip that does sinewave out, old modem chip,
2???, there are actually more.Have something to add? Share your thoughts — no account required.
Ask the community — no account required