Chip with simple program for Toy

[andrew queisser]

Hi Walter,

Thanks for the info and link, guess I'll have some reading to do this
weekend.

Your TLC272 is a poor choice for this application; if you look on its
datasheet you'll see that, characteristic of CMOS opamps, it is specified
only down to 10k loads (so you're off by a factor of 500 or so), and it is
not stable with capacitive loads (the typical capacitance of a long-ish
headphone cord is enough to set it oscillating). Its current drive
capability is very weak - although it's specified for a max current of
30mA, the amount of current it can drive while still having any sort of
gain, bandwidth, and distortion spec is more like a tenth of that. You
would be far, far better off with something like an OPA2134 (or even a
TL072), though IMHO these still do not really have enough current drive,
even with two sections paralleled.

I read some articles by Chu Moy and he used the OPA too. We have a lot of
different opamps in our bin stock here but no OPA so I picked one with a
decent output current but I didn't understand the relationship to distortion
and gain. My plan was to learn about opamps with the stuff on hand and then
order some parts that are more appropriate. I'm actually surprised that the
sound is pretty good to my ears given that I've committed other sins like
using cheap caps for decoupling.

Rather than paralleling opamps, you might consider the common approach of
adding a discrete class-B buffer to the output. Self gives an example
circuit in his article. One caution: although Self says that he did not
need any compensation to avoid oscillation, in my own experience I've
found it necessary to put a small (47pF or so) capacitor in parallel with
the feedback resistor.


This sounds like a good idea - I might go for that.

Andrew

 

[andrew queisser]

Hi Andrew,

I assume the TLC272 is a 'rail to rail' amplifier. That means it should be
able
to swing +/- 4.5V at the output. Into a 25 ohm load the load current would
be
+/- 180mA but the chip will current limit long before that.

You'll therefore get more output by operating 2 sections in 'parallel'.
You
don't need more volts ( as you'd get by bridging ).

Configure the second half of the op-amp as a voltage follower connected to
the
first half's output and connect the outputs together via a couple of low
value
Rs ( say 10 ohms ) in series with each output pin ( for current sharing ).

Graham

Ahh, I see, I was using the wrong terms. I meant to ask about paralleling

the inputs and outputs but I said bridging instead. I'll try the voltage
follower.

Thanks,
Andrew

 

[Richard the Dreaded Liber]

On Fri, 13 Jan 2006 18:17:27 +0000, Peter Hucker wrote:

On Fri, 13 Jan 2006 11:31:36 -0000, ah <splifingate@gmail.com> wrote:

Rich Grise wrote:
On Sat, 07 Jan 2006 08:06:50 +0000, ah wrote:

Rich Grise wrote:
On Wed, 14 Dec 2005 20:43:05 +0000, Peter Hucker wrote:
On Wed, 14 Dec 2005 17:31:31 -0000, ah <splifingate@gmail.com> wrote:

"Some marajuana" is never anywhere near specific.

"Dope will get you through times of no money better than money will get
you through times of no dope."
-- Fabulous Furry Freak Brothers

"Dope will get you through times of no pussy better than money will."
-- some cow-orker in the EMR shop at Beale AFB, CA, ca. 1974

Cheers!
Rich

[1] EMR = Electromagnetic Reconnaissance. Or, depending whom you're
talking to, Educable Mentally Retarded. ;-P

IAWTP.

WTF IAWTP? "I Am Wet Toilet Paper?"

I Am With The Police.

Your spelling sux. Try this site: http://dictionary.reference.com/search?q=pig

Well, like I said, "I am Wet Toilet Paper." Is there a difference, after
all? ;-P

Cheers!
Rich
--
"We have met the enemy and he is us." - Pogo Possum

 

[ah]

Peter Hucker wrote:

On Fri, 13 Jan 2006 11:31:36 -0000, ah <splifingate@gmail.com> wrote:

Rich Grise wrote:
On Sat, 07 Jan 2006 08:06:50 +0000, ah wrote:

Rich Grise wrote:
On Wed, 14 Dec 2005 20:43:05 +0000, Peter Hucker wrote:
On Wed, 14 Dec 2005 17:31:31 -0000, ah <splifingate@gmail.com> wrote:

"Some marajuana" is never anywhere near specific.

"Dope will get you through times of no money better than money will get
you through times of no dope."
-- Fabulous Furry Freak Brothers

"Dope will get you through times of no pussy better than money will."
-- some cow-orker in the EMR shop at Beale AFB, CA, ca. 1974

Cheers!
Rich

[1] EMR = Electromagnetic Reconnaissance. Or, depending whom you're
talking to, Educable Mentally Retarded. ;-P

IAWTP.

WTF IAWTP? "I Am Wet Toilet Paper?"

I Am With The Police.

Your spelling sux. Try this site: http://dictionary.reference.com/search?q=pig

Your lingo sux.

Try this site: http://dictionary.reference.com/search?q=Miranda%20Rights
--
ah

 

[tssk]

"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...

Peter Hucker wrote:
On Fri, 13 Jan 2006 11:31:36 -0000, ah <splifingate@gmail.com> wrote:

Rich Grise wrote:
On Sat, 07 Jan 2006 08:06:50 +0000, ah wrote:

Rich Grise wrote:
On Wed, 14 Dec 2005 20:43:05 +0000, Peter Hucker wrote:
On Wed, 14 Dec 2005 17:31:31 -0000, ah <splifingate@gmail.com
wrote:

"Some marajuana" is never anywhere near specific.

"Dope will get you through times of no money better than money will
get
you through times of no dope."
-- Fabulous Furry Freak Brothers

"Dope will get you through times of no pussy better than money will."
-- some cow-orker in the EMR shop at Beale AFB, CA, ca. 1974

Cheers!
Rich

[1] EMR = Electromagnetic Reconnaissance. Or, depending whom you're
talking to, Educable Mentally Retarded. ;-P

IAWTP.

WTF IAWTP? "I Am Wet Toilet Paper?"

I Am With The Police.

Your spelling sux. Try this site:
http://dictionary.reference.com/search?q=pig

Your lingo sux.
~

So, we are back to the de facto that he's a cunning linguist - or not?
~

 

[Peter Hucker]

On Fri, 13 Jan 2006 22:06:58 -0000, ah <splifingate@gmail.com> wrote:

Peter Hucker wrote:
On Fri, 13 Jan 2006 11:31:36 -0000, ah <splifingate@gmail.com> wrote:

Rich Grise wrote:
On Sat, 07 Jan 2006 08:06:50 +0000, ah wrote:

Rich Grise wrote:

IAWTP.

WTF IAWTP? "I Am Wet Toilet Paper?"

I Am With The Police.

Your spelling sux. Try this site: http://dictionary.reference.com/search?q=pig

Your lingo sux.

Try this site: http://dictionary.reference.com/search?q=Miranda%20Rights

Don't call me Miranda in public.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

A certain little girl, when asked her name, would reply, "I'm Mr. Sugarbrown's daughter."
Her mother told her this was wrong, she must say, "I'm Jane Sugarbrown."
The Vicar spoke to her in Sunday School, and said, "Aren't you Mr. Sugarbrown's daughter?"
She replied, "I thought I was, but mother says I'm not."

 

[ah]

tssk wrote:

"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...
Peter Hucker wrote:
On Fri, 13 Jan 2006 11:31:36 -0000, ah <splifingate@gmail.com> wrote:

Rich Grise wrote:
On Sat, 07 Jan 2006 08:06:50 +0000, ah wrote:

Rich Grise wrote:
On Wed, 14 Dec 2005 20:43:05 +0000, Peter Hucker wrote:
On Wed, 14 Dec 2005 17:31:31 -0000, ah <splifingate@gmail.com
wrote:

"Some marajuana" is never anywhere near specific.

"Dope will get you through times of no money better than money will
get
you through times of no dope."
-- Fabulous Furry Freak Brothers

"Dope will get you through times of no pussy better than money will."
-- some cow-orker in the EMR shop at Beale AFB, CA, ca. 1974

Cheers!
Rich

[1] EMR = Electromagnetic Reconnaissance. Or, depending whom you're
talking to, Educable Mentally Retarded. ;-P

IAWTP.

WTF IAWTP? "I Am Wet Toilet Paper?"

I Am With The Police.

Your spelling sux. Try this site:
http://dictionary.reference.com/search?q=pig

Your lingo sux.
~
So, we are back to the de facto that he's a cunning linguist - or not?
~

What.
--
ah

 

[ah]

Peter Hucker wrote:

On Fri, 13 Jan 2006 22:06:58 -0000, ah <splifingate@gmail.com> wrote:

Peter Hucker wrote:
On Fri, 13 Jan 2006 11:31:36 -0000, ah <splifingate@gmail.com> wrote:

Rich Grise wrote:
On Sat, 07 Jan 2006 08:06:50 +0000, ah wrote:

Rich Grise wrote:

IAWTP.

WTF IAWTP? "I Am Wet Toilet Paper?"

I Am With The Police.

Your spelling sux. Try this site: http://dictionary.reference.com/search?q=pig

Your lingo sux.

Try this site: http://dictionary.reference.com/search?q=Miranda%20Rights

Don't call me Miranda in public.

Shirley, you don't mean that?
--
ah

 

[tssk]

"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...
Peter Hucker wrote:
On Fri, 13 Jan 2006 11:31:36 -0000, ah <splifingate@gmail.com> wrote:

Rich Grise wrote:
On Sat, 07 Jan 2006 08:06:50 +0000, ah wrote:

Rich Grise wrote:
On Wed, 14 Dec 2005 20:43:05 +0000, Peter Hucker wrote:
On Wed, 14 Dec 2005 17:31:31 -0000, ah <splifingate@gmail.com
wrote:

"Some marajuana" is never anywhere near specific.

"Dope will get you through times of no money better than money will
get
you through times of no dope."
-- Fabulous Furry Freak Brothers

"Dope will get you through times of no pussy better than money
will."
-- some cow-orker in the EMR shop at Beale AFB, CA, ca. 1974

Cheers!
Rich

[1] EMR = Electromagnetic Reconnaissance. Or, depending whom you're
talking to, Educable Mentally Retarded. ;-P

IAWTP.

WTF IAWTP? "I Am Wet Toilet Paper?"

I Am With The Police.

Your spelling sux. Try this site:
http://dictionary.reference.com/search?q=pig

Your lingo sux.
~
So, we are back to the de facto that he's a cunning linguist - or not?
~

What.
~

It was a cunning reply from a linguist?
Wake up man!
~

 

[ah]

tssk wrote:

"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...
tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...
Peter Hucker wrote:
On Fri, 13 Jan 2006 11:31:36 -0000, ah <splifingate@gmail.com> wrote:

Rich Grise wrote:
On Sat, 07 Jan 2006 08:06:50 +0000, ah wrote:

Rich Grise wrote:
On Wed, 14 Dec 2005 20:43:05 +0000, Peter Hucker wrote:
On Wed, 14 Dec 2005 17:31:31 -0000, ah <splifingate@gmail.com
wrote:

"Some marajuana" is never anywhere near specific.

"Dope will get you through times of no money better than money will
get
you through times of no dope."
-- Fabulous Furry Freak Brothers

"Dope will get you through times of no pussy better than money
will."
-- some cow-orker in the EMR shop at Beale AFB, CA, ca. 1974

Cheers!
Rich

[1] EMR = Electromagnetic Reconnaissance. Or, depending whom you're
talking to, Educable Mentally Retarded. ;-P

IAWTP.

WTF IAWTP? "I Am Wet Toilet Paper?"

I Am With The Police.

Your spelling sux. Try this site:
http://dictionary.reference.com/search?q=pig

Your lingo sux.
~
So, we are back to the de facto that he's a cunning linguist - or not?
~

What.
~
It was a cunning reply from a linguist?
Wake up man!
~

Oh, sorry: it's always "Was that the biggest telephone pole you've ever seen,
or what?" over on this side of the Pond.
--
ah

 

[Peter Hucker]

On Sat, 14 Jan 2006 03:52:12 -0000, ah <splifingate@gmail.com> wrote:

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...
tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...
Peter Hucker wrote:

Your lingo sux.
~
So, we are back to the de facto that he's a cunning linguist - or not?
~

What.
~
It was a cunning reply from a linguist?
Wake up man!
~

Oh, sorry: it's always "Was that the biggest telephone pole you've ever seen,
or what?" over on this side of the Pond.

What?

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

It is bad luck to be superstitious.

 

[ah]

Peter Hucker wrote:

On Sat, 14 Jan 2006 03:52:12 -0000, ah <splifingate@gmail.com> wrote:

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...
tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...
Peter Hucker wrote:

Your lingo sux.
~
So, we are back to the de facto that he's a cunning linguist - or not?
~

What.
~
It was a cunning reply from a linguist?
Wake up man!
~

Oh, sorry: it's always "Was that the biggest telephone pole you've ever seen,
or what?" over on this side of the Pond.

What?

Exactly.
--
ah

 

[tssk]

"ah" <splifingate@gmail.com> wrote in message
news:fvgyf.5855$6L1.4571@trnddc02...

Peter Hucker wrote:
On Sat, 14 Jan 2006 03:52:12 -0000, ah <splifingate@gmail.com> wrote:

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...
tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...
Peter Hucker wrote:

Your lingo sux.
~
So, we are back to the de facto that he's a cunning linguist - or
not?
~

What.
~
It was a cunning reply from a linguist?
Wake up man!
~

Oh, sorry: it's always "Was that the biggest telephone pole you've ever
seen,
or what?" over on this side of the Pond.

What?

Exactly.
~

Harumph... existentialists - never have trusted them.
~

 

[ah]

tssk wrote:

"ah" <splifingate@gmail.com> wrote in message
news:fvgyf.5855$6L1.4571@trnddc02...
Peter Hucker wrote:
On Sat, 14 Jan 2006 03:52:12 -0000, ah <splifingate@gmail.com> wrote:

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...
tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...
Peter Hucker wrote:

Your lingo sux.
~
So, we are back to the de facto that he's a cunning linguist - or
not?
~

What.
~
It was a cunning reply from a linguist?
Wake up man!
~

Oh, sorry: it's always "Was that the biggest telephone pole you've ever
seen,
or what?" over on this side of the Pond.

What?

Exactly.
~
Harumph... existentialists - never have trusted them.
~

But, how do you /know/ they exist?
--
ah

 

[tssk]

"ah" <splifingate@gmail.com> wrote in message
news:20nyf.895$MG1.149@trnddc05...

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:fvgyf.5855$6L1.4571@trnddc02...
Peter Hucker wrote:
On Sat, 14 Jan 2006 03:52:12 -0000, ah <splifingate@gmail.com> wrote:

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...
tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...
Peter Hucker wrote:

Your lingo sux.
~
So, we are back to the de facto that he's a cunning linguist - or
not?
~

What.
~
It was a cunning reply from a linguist?
Wake up man!
~

Oh, sorry: it's always "Was that the biggest telephone pole you've
ever
seen,
or what?" over on this side of the Pond.

What?

Exactly.
~
Harumph... existentialists - never have trusted them.
~

But, how do you /know/ they exist?
--
ah
~

Exactly! That's why I don't trust 'em...
~

 

[Peter Hucker]

On Sun, 15 Jan 2006 00:16:11 -0000, ah <splifingate@gmail.com> wrote:

Peter Hucker wrote:
On Sat, 14 Jan 2006 03:52:12 -0000, ah <splifingate@gmail.com> wrote:

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...
tssk wrote:

What.
~
It was a cunning reply from a linguist?
Wake up man!
~

Oh, sorry: it's always "Was that the biggest telephone pole you've ever seen,
or what?" over on this side of the Pond.

What?

Exactly.

Eh?

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

A Scotsman and a Jew went to a restaurant.
After a hearty meal, the waitress came by with the inevitable check.
To the amazement of all, the Scotsman was heard to say, "I'll pay it!"
The next morning's newspaper carried the news item: "JEWISH VENTRILOQUIST FOUND MURDERED IN ALLEY".

 

[ah]

tssk wrote:

"ah" <splifingate@gmail.com> wrote in message
news:20nyf.895$MG1.149@trnddc05...
tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:fvgyf.5855$6L1.4571@trnddc02...
Peter Hucker wrote:
On Sat, 14 Jan 2006 03:52:12 -0000, ah <splifingate@gmail.com> wrote:

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...
tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:6wVxf.82$Di.25@trnddc06...
Peter Hucker wrote:

Your lingo sux.
~
So, we are back to the de facto that he's a cunning linguist - or
not?
~

What.
~
It was a cunning reply from a linguist?
Wake up man!
~

Oh, sorry: it's always "Was that the biggest telephone pole you've
ever
seen,
or what?" over on this side of the Pond.

What?

Exactly.
~
Harumph... existentialists - never have trusted them.
~

But, how do you /know/ they exist?
--
ah
~
Exactly! That's why I don't trust 'em...
~

Enough of this transcendental masturbation!

Where's the Skotch?!
--
ah

 

[ah]

Peter Hucker wrote:

On Sun, 15 Jan 2006 00:16:11 -0000, ah <splifingate@gmail.com> wrote:

Peter Hucker wrote:
On Sat, 14 Jan 2006 03:52:12 -0000, ah <splifingate@gmail.com> wrote:

tssk wrote:
"ah" <splifingate@gmail.com> wrote in message
news:mgXxf.824$he.14@trnddc03...
tssk wrote:

What.
~
It was a cunning reply from a linguist?
Wake up man!
~

Oh, sorry: it's always "Was that the biggest telephone pole you've ever seen,
or what?" over on this side of the Pond.

What?

Exactly.

Eh?

Dude #1: "Is she a looker, or what?"
Dude #2: "What."
--
ah

 

[Lord Garth]

<vze24h5m@verizon.net> wrote in message
news:1137191038.133014.34510@o13g2000cwo.googlegroups.com...

logjam wrote:
Is that why all of mine have been gutted of their parts?

The manual is sure pretty scary. This is Rev.2 and there are incorrect
labels on jumpers all over the place.

Is this 4k DRAM board decent? It doesn't look like a kit model.

http://www.stockly.com/images2/060108-76_Front.jpg

If you like, I think I can locate the schematic of the 64k dram board I used
in my Altair....you might modify it to use 8) 64k drams rather than the
4116 types.

 

[Rich Grise]

On Tue, 17 Jan 2006 15:28:16 +0000, Derek Potter wrote:

On Tue, 17 Jan 2006 00:08:38 GMT, Rich Grise <richgrise@example.net
wrote:


Next, I'm gonna see what happens when I take the magnetic shunts out;
http://www.abiengr.com/~sysop/images/MOT-primary2.jpg
has anyone ever done this, and is it a good idea?
[the penny is only for scale, but I did have this wild-ass idea that the
induced eddy currents would make magnetic effects that would be physically
observable, but no such luck. )-; ]

And at only 1.4 amps, is it worth the bother to wind more primary
turns?

Not unless it's running far too hot. By using more turns, you just
waste the magnetic capacity of the core by reducing the flux. You're
also adding series copper which will increase the losses.

You want minimum turns for the highest acceptable flux density and
then use as much copper as the core will take. That gives you amximum
power throughput.

And are there other newsgroups that might want to participate in a MOT
saga? ;-)

Not yet..... newgroup alt.mot.flash.flash.flaaaaaaaaa

Thanks Everybody! This thread has been very enlightening!

Thanks!
Rich