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Am 27.04.19 um 00:37 schrieb tabbypurr:
One thing about the classic National LM324 is that if you rail any
section, it wrecks the shared bias supplies for the other sections. So
one comparator switching *really* messes up whatever the other three
amps are doing.
I think some peoples' later versions didn't do that.
The 324 is my favourite opamp ever. You get so much for so little.
Hm. It definitely needs better output biasing.
In a previous life I have made a LM124-like op amp on an
analog array, and also a LM139-like comparator.
Not a bad architecture when all the good PNP transistors you have
are substrate transistors. I.E. their collectors are preconnected
to the substrate. A extra mA and a VBE multiplier were essential.
Current mirrors with pnp lateral transistors are a joke.
Nevertheless it was surprising what could be done with
1 metal layer and a few predefined resistors and transistors.
And there was a 30 pF cap per cell. That one was huge.
regards,
Gerhard
On Wednesday, 1 May 2019 17:39:28 UTC+1, Gerhard Hoffmann wrote:
Am 27.04.19 um 00:37 schrieb tabbypurr:
One thing about the classic National LM324 is that if you rail any
section, it wrecks the shared bias supplies for the other sections. So
one comparator switching *really* messes up whatever the other three
amps are doing.
I think some peoples' later versions didn't do that.
The 324 is my favourite opamp ever. You get so much for so little.
Hm. It definitely needs better output biasing.
In a previous life I have made a LM124-like op amp on an
analog array, and also a LM139-like comparator.
Not a bad architecture when all the good PNP transistors you have
are substrate transistors. I.E. their collectors are preconnected
to the substrate. A extra mA and a VBE multiplier were essential.
Current mirrors with pnp lateral transistors are a joke.
Nevertheless it was surprising what could be done with
1 metal layer and a few predefined resistors and transistors.
And there was a 30 pF cap per cell. That one was huge.
regards,
Gerhard
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
NT
On 2019-04-24 14:17, Gerhard Hoffmann wrote:
Am 24.04.19 um 21:35 schrieb Joerg:
1. EMI behavior of opamps. This is generally not understood at all by
engineers and (still!) not taught at universities from what young EEs
told me. A bipolar input stage will rectify RF at the first BE
junction, even stuff at cell phone frequencies. This rectification or
demodulation is very inefficient but since that is inside the loop any
resultying baseband AM will hit at full tilt because it happens at
"open loop".
It's not that FETs are any worse at demodulating than BJTs, it's just
that they need a higher source impedance for the same dBms. Say, a
different cable transformation.
MOSFETs don't demodulate at all because there is no conducting diode
path. I have found cases with hardcore EM susceptibility to the point
where a person outside the concrete walls of the building could upset a
circuit operating at single-digit kHz range, just by turning on their
cell phone. GSM ones were especially bad. After switching to a CMOS
opamp ... nad, zilch, not even when holding a cell phone right above the
open circuit and then turning it on.
A downside is that one can often not achieve the same low noise
performance with CMOS opamps.
IIRC, there is a nice triggered oscillator in the interpolator ofI've been tweaking my 500 MHz triggered Colpitts oscillator [1]. It's
now common-collector, using either a bipolar NPN or an enhancement
phemt. I'm seeing DC effects at startup.
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
On Wednesday, 1 May 2019 17:39:28 UTC+1, Gerhard Hoffmann wrote:
Am 27.04.19 um 00:37 schrieb tabbypurr:
One thing about the classic National LM324 is that if you rail any
section, it wrecks the shared bias supplies for the other sections. So
one comparator switching *really* messes up whatever the other three
amps are doing.
I think some peoples' later versions didn't do that.
The 324 is my favourite opamp ever. You get so much for so little.
Hm. It definitely needs better output biasing.
In a previous life I have made a LM124-like op amp on an
analog array, and also a LM139-like comparator.
Not a bad architecture when all the good PNP transistors you have
are substrate transistors. I.E. their collectors are preconnected
to the substrate. A extra mA and a VBE multiplier were essential.
Current mirrors with pnp lateral transistors are a joke.
Nevertheless it was surprising what could be done with
1 metal layer and a few predefined resistors and transistors.
And there was a 30 pF cap per cell. That one was huge.
regards,
Gerhard
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
NT
There are some dual and quad 741 equivalents that are also crazy
cheap, but aren't as bad as a 324.
Am 01.05.19 um 22:08 schrieb John Larkin:
I've been tweaking my 500 MHz triggered Colpitts oscillator [1]. It's
now common-collector, using either a bipolar NPN or an enhancement
phemt. I'm seeing DC effects at startup.
IIRC, there is a nice triggered oscillator in the interpolator of
the HP5370 time interval counter. That's from the time when the
circuits were in the manuals. Should be easy to find.
regards,
Gerhard
On Wednesday, 1 May 2019 17:39:28 UTC+1, Gerhard Hoffmann wrote:
Am 27.04.19 um 00:37 schrieb tabbypurr:
One thing about the classic National LM324 is that if you rail any
section, it wrecks the shared bias supplies for the other sections. So
one comparator switching *really* messes up whatever the other three
amps are doing.
I think some peoples' later versions didn't do that.
The 324 is my favourite opamp ever. You get so much for so little.
Hm. It definitely needs better output biasing.
In a previous life I have made a LM124-like op amp on an
analog array, and also a LM139-like comparator.
Not a bad architecture when all the good PNP transistors you have
are substrate transistors. I.E. their collectors are preconnected
to the substrate. A extra mA and a VBE multiplier were essential.
Current mirrors with pnp lateral transistors are a joke.
Nevertheless it was surprising what could be done with
1 metal layer and a few predefined resistors and transistors.
And there was a 30 pF cap per cell. That one was huge.
regards,
Gerhard
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
On Wednesday, 1 May 2019 17:39:28 UTC+1, Gerhard Hoffmann wrote:
Am 27.04.19 um 00:37 schrieb tabbypurr:
One thing about the classic National LM324 is that if you rail any
section, it wrecks the shared bias supplies for the other sections. So
one comparator switching *really* messes up whatever the other three
amps are doing.
I think some peoples' later versions didn't do that.
The 324 is my favourite opamp ever. You get so much for so little.
Hm. It definitely needs better output biasing.
In a previous life I have made a LM124-like op amp on an
analog array, and also a LM139-like comparator.
Not a bad architecture when all the good PNP transistors you have
are substrate transistors. I.E. their collectors are preconnected
to the substrate. A extra mA and a VBE multiplier were essential.
Current mirrors with pnp lateral transistors are a joke.
Nevertheless it was surprising what could be done with
1 metal layer and a few predefined resistors and transistors.
And there was a 30 pF cap per cell. That one was huge.
regards,
Gerhard
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
On Wednesday, 1 May 2019 17:39:28 UTC+1, Gerhard Hoffmann wrote:
Am 27.04.19 um 00:37 schrieb tabbypurr:
One thing about the classic National LM324 is that if you rail any
section, it wrecks the shared bias supplies for the other sections. So
one comparator switching *really* messes up whatever the other three
amps are doing.
I think some peoples' later versions didn't do that.
The 324 is my favourite opamp ever. You get so much for so little.
Hm. It definitely needs better output biasing.
In a previous life I have made a LM124-like op amp on an
analog array, and also a LM139-like comparator.
Not a bad architecture when all the good PNP transistors you have
are substrate transistors. I.E. their collectors are preconnected
to the substrate. A extra mA and a VBE multiplier were essential.
Current mirrors with pnp lateral transistors are a joke.
Nevertheless it was surprising what could be done with
1 metal layer and a few predefined resistors and transistors.
And there was a 30 pF cap per cell. That one was huge.
regards,
Gerhard
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
On Thu, 2 May 2019 05:04:44 -0700 (PDT), tabbypurr wrote:
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
Anyone using scrap deserves what they get.
I won't even use a part
that's fallen on the floor or has escaped my sight. It's just not
worth the hassle to save a nickel (or less).
On Friday, 3 May 2019 02:49:27 UTC+1, k...@notreal.com wrote:
On Thu, 2 May 2019 05:04:44 -0700 (PDT), tabbypurr wrote:
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
Anyone using scrap deserves what they get.
absolutely, they get to make a living & eat.
I won't even use a part
that's fallen on the floor or has escaped my sight. It's just not
worth the hassle to save a nickel (or less).
For you, no. Many aren't so lucky.
On Fri, 3 May 2019 02:14:26 -0700 (PDT), tabbypurr wrote:
On Friday, 3 May 2019 02:49:27 UTC+1, k...@notreal.com wrote:
On Thu, 2 May 2019 05:04:44 -0700 (PDT), tabbypurr wrote:
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
Anyone using scrap deserves what they get.
absolutely, they get to make a living & eat.
Bullshit.
I won't even use a part
that's fallen on the floor or has escaped my sight. It's just not
worth the hassle to save a nickel (or less).
For you, no. Many aren't so lucky.
Luck has nothing to do with it.
On Friday, 3 May 2019 02:49:27 UTC+1, k...@notreal.com wrote:
On Thu, 2 May 2019 05:04:44 -0700 (PDT), tabbypurr wrote:
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
Anyone using scrap deserves what they get.
absolutely, they get to make a living & eat.
I won't even use a part
that's fallen on the floor or has escaped my sight. It's just not
worth the hassle to save a nickel (or less).
For you, no. Many aren't so lucky.
NT
On Saturday, 4 May 2019 05:32:20 UTC+1, k...@notreal.com wrote:
On Fri, 3 May 2019 02:14:26 -0700 (PDT), tabbypurr wrote:
On Friday, 3 May 2019 02:49:27 UTC+1, k...@notreal.com wrote:
On Thu, 2 May 2019 05:04:44 -0700 (PDT), tabbypurr wrote:
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
Anyone using scrap deserves what they get.
absolutely, they get to make a living & eat.
Bullshit.
nope, that's what they get
They deserve scrap.
since you don't know a thing about them
Their customer is getting screwed.
no, the customer gets a good deal.
I won't even use a part
that's fallen on the floor or has escaped my sight. It's just not
worth the hassle to save a nickel (or less).
For you, no. Many aren't so lucky.
Luck has nothing to do with it.
Clue has nothing to do with it in your case.
NT
On Fri, 3 May 2019 02:14:26 -0700 (PDT), tabbypurr@gmail.com wrote:
On Friday, 3 May 2019 02:49:27 UTC+1, k...@notreal.com wrote:
On Thu, 2 May 2019 05:04:44 -0700 (PDT), tabbypurr wrote:
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
Anyone using scrap deserves what they get.
absolutely, they get to make a living & eat.
I won't even use a part
that's fallen on the floor or has escaped my sight. It's just not
worth the hassle to save a nickel (or less).
For you, no. Many aren't so lucky.
NT
What do you do that's so price sensitive?
Do you have a lot of test failures form using reclaimed parts?
On Sat, 4 May 2019 00:48:30 -0700 (PDT), tabbypurr wrote:
On Saturday, 4 May 2019 05:32:20 UTC+1, k...@notreal.com wrote:
On Fri, 3 May 2019 02:14:26 -0700 (PDT), tabbypurr wrote:
On Friday, 3 May 2019 02:49:27 UTC+1, k...@notreal.com wrote:
On Thu, 2 May 2019 05:04:44 -0700 (PDT), tabbypurr wrote:
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
Anyone using scrap deserves what they get.
absolutely, they get to make a living & eat.
Bullshit.
nope, that's what they get
So you screw your customers. No surprise.
They deserve scrap.
since you don't know a thing about them
You *SAID* they were scrap, dumbass!
Their customer is getting screwed.
no, the customer gets a good deal.
No, he gets screwed. You're a thief.
I won't even use a part
that's fallen on the floor or has escaped my sight. It's just not
worth the hassle to save a nickel (or less).
For you, no. Many aren't so lucky.
Luck has nothing to do with it.
Clue has nothing to do with it in your case.
NT
On Fri, 3 May 2019 02:14:26 -0700 (PDT), tabbypurr wrote:
On Friday, 3 May 2019 02:49:27 UTC+1, k...@notreal.com wrote:
On Thu, 2 May 2019 05:04:44 -0700 (PDT), tabbypurr wrote:
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
Anyone using scrap deserves what they get.
absolutely, they get to make a living & eat.
I won't even use a part
that's fallen on the floor or has escaped my sight. It's just not
worth the hassle to save a nickel (or less).
For you, no. Many aren't so lucky.
What do you do that's so price sensitive?
On 5/5/19 1:06 am, John Larkin wrote:
What do you do that's so price sensitive?
Do you have a lot of test failures form using reclaimed parts?
I've gleaned that he lives in India, where $15/week is a basic living.
anything that can be scavenged and turned into rupiah can change
someone's life.
krw probably thinks they're poor because they haven't
shown enough initiative so they deserve it, but he's probably never
visited. He probably can't spell "privilege" either.
Clifford Heath.
On Sunday, 5 May 2019 04:01:54 UTC+1, Clifford Heath wrote:
On 5/5/19 1:06 am, John Larkin wrote:
What do you do that's so price sensitive?
Do you have a lot of test failures form using reclaimed parts?
I've gleaned that he lives in India, where $15/week is a basic living.
UK. Assembly is dotted about the developing world. At the extreme end some previously made as little as 8-10p a day, under 15 cents.
At that point it's hard to afford enough calories to survive, so..
that's true at 10p a day. Also corn alone does not deliver the right nutrients.
anything that can be scavenged and turned into rupiah can change
someone's life.
Yes, but I do design these things to be reliable, safe & nontoxic, it's not just a free for all. I don't want to create more problems.
On 5/5/19 1:06 am, John Larkin wrote:
On Fri, 3 May 2019 02:14:26 -0700 (PDT), tabbypurr@gmail.com wrote:
On Friday, 3 May 2019 02:49:27 UTC+1, k...@notreal.com wrote:
On Thu, 2 May 2019 05:04:44 -0700 (PDT), tabbypurr wrote:
On Thursday, 2 May 2019 02:44:04 UTC+1, k...@notreal.com wrote:
On Wed, 1 May 2019 11:51:17 -0700 (PDT), tabbypurr wrote:
There's only one good thing to say about the 324: the price. And that's the point. Price matters for a whole lot of people.
Even that isn't so great. There is _nothing_ to recommend the '324,
these days. Fifty years ago, sure. Today, nope. No way.
The price is the best it gets. The more there are in scrap, the less labour it takes to get them. And you get 4 for the same work as 2 with other opamps.
Anyone using scrap deserves what they get.
absolutely, they get to make a living & eat.
I won't even use a part
that's fallen on the floor or has escaped my sight. It's just not
worth the hassle to save a nickel (or less).
For you, no. Many aren't so lucky.
NT
What do you do that's so price sensitive?
Do you have a lot of test failures form using reclaimed parts?
I've gleaned that he lives in India, where $15/week is a basic living.
At that point it's hard to afford enough calories to survive, so
anything that can be scavenged and turned into rupiah can change
someone's life. krw probably thinks they're poor because they haven't
shown enough initiative so they deserve it, but he's probably never
visited. He probably can't spell "privilege" either.