Chip with simple program for Toy

[Roger Johansson]

NoSpam@daqarta.com (Bob Masta) wrote:

This made carving a breeze, but after a half
hour or so of carving, I found my fingertips had a very strange
sensation. Even with everything turned off, there was still
a tingling. The strangest part was that if I tapped on something,
it felt like my fingers were little tuning forks... they seemed to
"ring" for a few seconds afterward.

Strong mechanical vibration have well known negative consequences, like
nerve damage and problems with blood vessels. The circulation is
hampered. But these effects appear at strong vibrations, like when using
a pneumatic sander.

I don't think the device we are talking about would need so strong
vibrations that there is any need to worry about such effects.

We touch and feel things all the time and that does not damage the nerves
or circulation.


--
Roger J.

 

[John Popelish]

Andy wrote:

Is John Popelish here? I changed the labeling since
my last post. I am still having difficulty to fully
grasp this circuit. My next questions are as follows:

I also removed the LED because we can see the simulation
without it, and it does not (I think) effect the analysis.

Agreed. minor effect.

Did you also lose the diode that connected between the base of Q1 and
ground? That has a big effect on frequency. Without that diode, R1
mostly affects the off time and R2 mostly affects the on time.

I have noticed that if we increase R2 from 47K to 2M the
circuit will still oscillate, but any further increase and
the circuit will not oscillate. I was wondering if I could
obtain a formula to calculate the maximum value (which is
2M by inspection of simulation results)

The exact value is dependent on the gain of the transistors and the
amount of bias current from R1. The resistor has to provide enough
positive feedback from the linear biased operating point to produce
closed loop gain greater than 1.

following is the lt spice asc file as modified by me:

Version 4
SHEET 1 880 680
WIRE 48 64 176 64
WIRE 240 112 240 320
WIRE 160 320 240 320
WIRE 240 320 240 384
WIRE 32 320 96 320
WIRE -48 320 -96 320
WIRE -96 320 -96 112
WIRE -16 112 -96 112
WIRE -96 112 -96 0
WIRE -96 -80 -96 -144
WIRE -96 -144 240 -144
WIRE 528 -144 528 -128
WIRE 240 -144 240 16
WIRE 240 -144 528 -144
FLAG 48 160 0
FLAG 240 464 0
FLAG 528 -48 0
SYMBOL res 224 368 R0
SYMATTR InstName R3
SYMATTR Value 50
SYMBOL cap 160 304 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C
SYMATTR Value .47ľ
SYMBOL pnp 176 112 M180
SYMATTR InstName Q2
SYMATTR Value 2N3906
SYMBOL res 48 304 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R2
SYMATTR Value 47k
SYMBOL npn -16 64 R0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL res -112 -96 R0
SYMATTR InstName R1
SYMATTR Value 4e6
SYMBOL voltage 528 -144 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value PULSE(0 9 0)
TEXT -114 506 Left 0 !.tran 10s

--
John Popelish

 

[Terry Pinnell]

See also the thread resulting from OP's cross post in s.e.d. I asked a
few other questions there, in
news:9mtlr0d5t2u0dv6cr1torgmcvrio1l1lfc@4ax.com

I'm hoping he'll reply, as I'm curious about the cause.

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Lord Garth]

"Phil" <philSPAMKILLissler@comcast.net> wrote in message
news:j4qdnUrbR-e1QyLcRVn-2Q@comcast.com...

Does anyone have any information about where to obtain a replacement bulb
for the Quick-EII eprom eraser from ZAX Corp? I have tried to contact the
Japanese company that owns the ZAX name, but have received no reply. Any
documentation or info on this product would be appreciated. Thanks in
advance.

If this is a fluorescent type, the model number is on the quartz tube.
If it's an argon glow lamp, I don't know.

Are you sure there is no other problem like a defective interlock
that kills the lamp when the eraser is opened?

 

[Fritz Schlunder]

"Gary Helfert" <ghelfert@worldnet.att.net> wrote in message
news:WsSvd.126873$7i4.32941@bgtnsc05-news.ops.worldnet.att.net...

This is an academic question among my coworkers. Some believe it is
infinite, however I believe at some voltage the electrons will jump the
gap.
Any ideas?

Vacuum doesn't have infinite dielectric strength, however it can be fairly
large or really quite pitiful. I understand the shape of the electrodes
(needle points will concentrate electric field lines and decrease breakdown
strength), the temperature of the electrodes (high temperature leading to
thermionic emission which takes minimal voltage), and the specific electrode
material used (different vacuum work functions) will significantly alter the
effective dielectric strength of vacuum. Presumably cathode ray tube (CRT)
monitors and TVs use electron guns which work in vacuum but only require a
few tens of kV (but they use electrode heating) or less.

 

[John Larkin]

On Wed, 15 Dec 2004 08:20:06 GMT, "Gary Helfert"
<ghelfert@worldnet.att.net> wrote:

This is an academic question among my coworkers. Some believe it is
infinite, however I believe at some voltage the electrons will jump the gap.
Any ideas?

A vacuum can support a huge electric field, infinite except for
obscure quantum effects at incredible field levels. But real
electrodes will have surface emission effects that will rip ions out
of the metals or whatever; once a few ions get loose and whack the
opposite electrode, all hell breaks loose. It takes something like
1e8v/m to rip ions out of metal, but you can get that sort of field at
the tip of a rough spikey bit using only kilovolts. Clean high-vacuum
systems can work in the tens of megavolts per meter range, as I
recall.

As in interesting aside, look up the Farnsworth Multipactor effect.
It's cause some serious grief in satellite RF systems.

John

 

[Diefenbaker]

Thanks Andrew.

 

[peterken]

"Gary Helfert" <ghelfert@worldnet.att.net> wrote in message
news:WsSvd.126873$7i4.32941@bgtnsc05-news.ops.worldnet.att.net...

This is an academic question among my coworkers. Some believe it is
infinite, however I believe at some voltage the electrons will jump the
gap.
Any ideas?


Don't really know for vacuum, but I assume it's a better insulator as

"normal" air...
My (practical) experience is that 10kV / cm...12kV /cm can be done in a
"normal" environment without any breakdown (unless spikey surfaces or highly
humid air are involved)

 

[Greg Bender]

Thanks Rich! Hopefully someone will post a schematic.

 

[Rich Grise]

On Wed, 15 Dec 2004 23:06:39 -0500, kreb wrote:

I am going to build a power supply with 5 rechargeable giving me the 6
volts. But of course the problem is finding how to connect (hardwire) to
the flash without too much disturbance of the body. I am not sure how to
get into the unit and where to connect with the battery terminals as I am
not in as yet. This unit has only 4 battery slots so I must improvise if
I am going to be able to use the rechargeable.

Get two wood dowels, the size of AA cells. Put a metal tab on one end of
each, for your power supply terminals. Put these two sticks in the first
and last battery position, so that the tabs contact the 6V contacts. Put
your 5 x 1.2V. batteries in their own holder and call it the "power supply."

Be sure and get the polarity right!

Good Luck!
Rich

 

[CBarn24050]

Subject: Re: Voltage Shifting Question
From: "Andrew Holme" andrew@nospam.com
Date: 16/12/04 22:27 GMT Standard Time
Message-id: <cpt2ap$gpo$1$8300dec7@news.demon.co.uk

James Howe wrote:

is wired, the ramp ranges from -12v to -4v. I understand why this
works the way it does. However, the final output of the circuit
produces a ramp which ranges from -4v to +4v.

A basic high pass RC network always behaves this way. The AC wavform stays the
same but is level shifted such that the average voltage is equal to the voltage
that the resistor is conected to, in this case 0v. If you were to return the
resistor to -8v the wave would go back to -12v to -4v.

 

[Rich Grise]

On Thu, 16 Dec 2004 16:34:45 -0500, James Howe wrote:

I've been looking at a circuit which produces sawtooth oscillations. It
does this by sending a constant current to a capacitor which is part of a
circuit containing a 555 timer.

What? The other 12 answers weren't good enough?

You need to go to the public library.

Good Luck!
Rich

 

[Rich Grise]

On Sat, 18 Dec 2004 03:10:16 +0000, Gary Schafer wrote:

The manager was not entirely wrong. Specific gravity tells you if the
battery is charged and what percent of charge it is at. But the
battery can have a high internal resistance as another poster said.
What the guy at the store probably was talking about was a "load
test". It is commonly done in the battery service shops. They put a
load of so many amps and measure how much the voltage drops and how
quickly. That is the real test to see if the battery is any good.

Thanks for this. I knew it, but was negligent in not bothering to remember
it before posting my response.

Cheers!
Rich

On Fri, 17 Dec 2004 15:36:46 -0500, "Mike" <no_spam@comcast.net
wrote:

Hi Don,

"~" meant approximate, so I don't remember exactly what it read. Could have
been well over 13 volts, but the question in my post was whether that Sears
manager was BS'in me.

 

[Robert Baer]

AssTelescope wrote:

Howdy

I have an Antene here and I know it can be used for something. It would be
good to be able to pickup other stations (free to air) from around the globe
or simply just look for video streams.

What equipment would I need to make something like this useful (besides a tv
set).

Many thanks,

Ive attached three pics

[Image]

[Image]

[Image]

1) This NG is not the place for binaries (pictures).
2) That is mainly for TV in the UHF region.

 

[John Bäckstrand]

Not quite instantly.
The pressure you apply at the input end is propagated at the speed of
sound in the marble column

It is? This seems very un-intuitive to me. Dont know why, it just seems
wrong. Sure, sound is vibration in a medium (?) so it kind-of makes
sense. I guess the speed of sound in very hard materials is very high?

---
John Bäckstrand

 

[Franz Heymann]

"Bob Masta" <NoSpam@daqarta.com> wrote in message
news:41c44f7a.1431423@news.itd.umich.edu...

On 17 Dec 2004 11:26:40 -0800, billb@eskimo.com wrote:

[snip]

A good intuitive example is a pipe full of marbles. If you push
another marble into one end, a marble on the far end moves
out "instantly", even though it is a long way away.

Not quite instantly.
The pressure you apply at the input end is propagated at the speed of
sound in the marble column

Franz

 

[Doug]

John Bäckstrand wrote:

Not quite instantly.
The pressure you apply at the input end is propagated at the speed of
sound in the marble column

It is? This seems very un-intuitive to me. Dont know why, it just seems
wrong. Sure, sound is vibration in a medium (?) so it kind-of makes
sense. I guess the speed of sound in very hard materials is very high?

---
John Bäckstrand
Speed of sound in various solids in m/s from a web stie. I made no attempt

to confirm

Diamond 12000
Pyrex glass 5640
Iron 5130
Aluminum 5100
Brass 4700
Copper 3560
Gold 3240
Lucite 2680
Lead 1322
Rubber 1600

 

[MG]

"AssTelescope" <mr@mr.com> wrote in message
news:41c37608@duster.adelaide.on.net...

Howdy

I have an Antene here and I know it can be used for something. It would be
good to be able to pickup other stations (free to air) from around the
globe or simply just look for video streams.

What equipment would I need to make something like this useful (besides a
tv set).

Many thanks,

Ive attached three pics

Do not mean to be picky but the correct spelling is Antenna (singular).
As Robert explained, that antenna is for TV and at those frequencies, the
receiving antenna must be almost on the line of sight, no obstructions.
Whatever station you can receive you can easily drive to visit in a few
hours, no hexotic stuff around the world.
MG

 

[Anthony]

NoSpam@daqarta.com (Bob Masta) wrote in news:41af2700.3580034
@news.itd.umich.edu:

On 2 Dec 2004 03:46:30 -0800, arunsahlam@gmail.com wrote:

Hi,

I would like to control arund 100 electric switches from my PC.
Can someone guide me on this.

Thanks in advance

Arun Sahlam


You can do this with the standard parallel printer port.
It's easier if your system uses Win9x or DOS, but should
work from NT,2K, XP with an IO driver so you can get
access to the port.

The standard port has only 8 output lines, but it also
has several control lines. The trick is to make a multiplexer
8-bit latch chips. Use 4 control lines to select one of 16
latch chips to be updated from the common 8 lines.
That will give you 8 * 16 = 128 possible outputs.

There is lots of port info at www.lvr.com

Hope this helps!


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

I did this with my very first computer for a science fair project back in
83....a Tandy Color Computer....had a whopping 16K of extended
memory...but more importantly....it had a game port...
I built a card to plug in the port..used opto-isolators...through some
latches..and on to some high-capacity triacs..would switch 16 120VAC
loads...I just hooked up 16 lamps for the project...but you could have
ran your household appliances from it.
BTW...I've still got the old color computer
--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

 

[Anthony Fremont]

"Karl Uppiano" <karl.uppiano@verizon.net> wrote

Back in the late '70s, I used to pick up very distant FM stations
(with much
fading, but at times in perfect stereo) for a period of several hours
on
summer afternoons. I was in southwest Idaho, and the stations I picked
up
tended to be in Texas and Oklahoma. There is some sort of atmospheric
refraction that allows this. When this was going on, I could also pick
up
distant TV stations from the same areas, as well.

Sounds like Tropospheric Ducting. It happens when there is a thermal
inversion (warm air under cold air). The VHF signals tend to follow the
border between the cold and warm air masses and hence follows the
curvature of the Earth over the horizon.

I have keyed up a 2mtr repeater from >300 miles away using a handy-talky
and a rubber duck with full quieting into the machine.