Op amps problem Gain Calculation

[Anthony Fremont]

"Alexander" <electricdummy@hotmail.com> wrote in message
news:dusjmc$4gd$1@news5.zwoll1.ov.home.nl...

OK, I can give you some help.
1st: You probably have another chip than the 16F84.

Why would you say that? They are still quite available.

2nd the $ means the current PC
3rd don't use instructions that are for another family PIC's, the
16FXXX don't support DECFSZ. Look at the instruction set in the
manual.

Er, umm....yes they do.

Somhow RTFM (of the right chip) pops into my mind.

I heard that. ;-)

Looks to me like the OP needs to use CALL instead of GOTO.

 

[Alexander]

"Ash" <ashleyyouett@hotmail.com> schreef in bericht
news:1142086040.962303.75010@u72g2000cwu.googlegroups.com...

Unfortunately I am using the 16F84A chip and cannot change that, I
do
not have a manual for it as such but a few pieces of paper defining
the
35 commands it supports (which include decfsz) and overview of what
the
chip is capable of.

The code I quoted before does work, giving an 0.2 sec delay so the
PIC
is functioning fine and successfully decrements counters, my
question
was how can I extend this delay to 10 seconds as I have tried and
failed at numerous attempts loops.

I have tried using the CALL command but it did not work when I
programmed the chip. On the simulation in MPLAB it never seemed to
exit
the second subroutine despite the RETURN command at the end of the
routine with all the different variations of coding I tried.

If the code placed in the OP worked for a 0.2sec delay, you simply use

the following:

MOVLW, D'50'; 50 times 0.2 should be 10
MOVWF COUNT3 ; make variable first
DELAY10SEC
CALL SECTION
DECFSZ COUNT3
GOTO DELEY10SEC

Then paste the subroutine somewhere outside the main code, but before
"end"!

Alexander

p.s. I have not tested anything

 

[Anthony Fremont]

"Ash" <ashleyyouett@hotmail.com> wrote in message
news:1142086040.962303.75010@u72g2000cwu.googlegroups.com...

Unfortunately I am using the 16F84A chip and cannot change that, I do
not have a manual for it as such but a few pieces of paper defining
the
35 commands it supports (which include decfsz) and overview of what
the
chip is capable of.

Why not?
http://www.microchip.com/stellent/idcplgidcplg?IdcService=SS_GET_PAGE&nodeId=1335&dDocName=en010230

The code I quoted before does work, giving an 0.2 sec delay so the PIC
is functioning fine and successfully decrements counters, my question
was how can I extend this delay to 10 seconds as I have tried and
failed at numerous attempts loops.

I have tried using the CALL command but it did not work when I
programmed the chip. On the simulation in MPLAB it never seemed to
exit
the second subroutine despite the RETURN command at the end of the
routine with all the different variations of coding I tried.

"I also tried creating another subroutine that called DELAY by simply
going"

DELAY2 GOTO DELAY
GOTO DELAY
RETURN

Did you try changing the above code to:

DELAY2 CALL DELAY
CALL DELAY
RETURN

Another thing to check, the stack is only 8 levels deep so too much
nesting of calls will make it wrap around. Watch the stack level
closely in MPLAB

 

On Fri, 10 Mar 2006 21:05:47 +0000 (UTC), "Grumble"
<grumble53@yahoo.co.uk> wrote:

I was wondering if there is a way of converting the speaker output of a
cassette player to a signal suitable for line-input of a PC audio card.
There is no headphone-out on the device. The intention is to fit a car audio
cassette player into the PC. Will it even fit? Has anyone tried to do the
same thing? I know there is a company that makes one but it ain't cheap
http://plusdeck.com/englishsite/index.asp or at least it ain't as cheap as
I'd like it to be! I'd like to convert the family tape collection to mp3 but
I'm sick of all the cables and leads festooning this computer as it is
without adding any more to it with another piece of stand alone kit.

Thanks for any help

Ian

I'd just go ahead and try it. Line in is typically rated for one volt

input (if you over drive, it will clip the signal and be distorted).

A car system will output a maximum signal of just under its power
supply voltage. ~12 volts unless it is rated at some very high RMS
power output - then they may use an internal DC -DC converter to step
up the voltage - but that is just in those systems that make your ears
bleed, an inexpensive player won't use a power converter.

A car tape player may use a bridged amplifier so there is no common
between speakers - that may cause you a problem. They use two
amplifiers for each channel to increase the power - one amp is driven
with an out of phase signal - so its output will be high when the
other amp is low. Four amps for stereo . . . and it is quite common.

You might try using ground and one wire from each speaker output to
the line in and see if that works. Keep the output turned down low.

If that is still too much a resistor divider on the output will drop
the signal.

It may require some experimentation - the car amp is designed for a 4
ohm speaker load and may not work well on a much higher impedance
input so you may need a load resistor to keep the amp happy.

You may find all kinds of hum and hiss that wasn't noticeable with the
player in a car - you changed the power supply from a heavy DC battery
to the switching supply in the computer or some other supply that it
wasn't designed to work with.

You may have ground loops between the signal paths and supply current
paths.

The output of the car player may have a high noise level that will be
present all the time but only becomes noticeable when driving another
amp input (a voltage divider may help there).

All the problems have solutions - but you have to be able to track
them down and fix them.


--

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[lapépite]

Yes, that is an idea.
Roland
"Richard Harris" <none@none.com> wrote in message
news:duddde$cg1$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...

Sorry not sure what your talking about, what exactly do you mean by
water engine ? and are you just trying to create a printed circuit
board...
if so cant you go to a company that produces them.... many will take a pcb
layout or even schematic and produce the board for a charge.



"lapépite" <bonjourmadame@fsmail.net> wrote in message
news:du26om$9ig$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
Hi,

I am basically looking to expriment the water engine on a lawn mower.
There
is no really problem mecanicwise but I did not find somebody able to
build
the printed circuit for it according to the plan I have got.

Anyone interested or knowing someone who could be?

I am not interested in money business but more in something like: "we
build
our engine, put it in our car if it works and nobody knows"... To avoid
the
creation of taxes from governments on the system. Goverment can't help
it,
it has to tax anything that breathes...So I am more interested in it on a
charitable and friendly basis.
Maybe this is a bit utopia but I think that if we do not want to make
money
ot of it, who can do?

What you say?

regards

Roland

 

[Anthony Fremont]

"Richard Harris" <none@none.com> wrote in message
news:dv1haa$bl3$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...

Hi,
I have a plan for a PIC project but im not sure about the acuracy
that
can be achieved with a PIC.
Basicly I will be using a number of dealy routines but I need the PIC
to run
for 2 months and it must not lose more than 2 minutes per week. I
intend to
run it at 4MHz And the temperature should be fairly steady (code),
Should this be possible?

That's about 200 parts/million so yes,a 4MHz crystal will do the job
nicely, but it will burn up a couple of mA. Do you really need that
much speed for your application? You could run it from a 32,768Hz watch
crystal and run continuously (without sleeping) for months (if not
years) from AA cells. In either case, sleeping would increase your
battery life.

Also a question about relays, my understanding is you can use them to
switch
a high voltage from a low votage triger, and that you can use them as
a
simple switch, you aply voltage to one side and the other side
contacts. Is
this the case?

Pretty much, but a PIC isn't going to be able to directly drive much of
a relay. You'll need a driver transistor of some sort for most relays.
How much voltage are you wanting to switch? A MOSFET may be the way to
go instead of the relay.

Thanks for your time, any help is much appreciated.

 

[Richard Harris]

Thanks you very very very much

That was exactly what i needed to know.
I love the idea of using a watch crystal and yup I dont need to run at such
speed.

The reason i wanted to use a relay is I have a push button on a device and I
need to triger it from a PIC, I dont know how the switch is hooked up, all I
know is that the device is running of 3V, so i figured if I replaced the
push
button switch with a relay and trigered it from the PIC I would be sorted.

(I know nothing about electronics so this seemed a simple sure way of
achiving what I needed)

Cant thank you enough.

PS Im about to make a killing $$$$ with some electronics that cost a few
dolars, aint that funy, considering

"Anthony Fremont" <spam@anywhere.com> wrote in message
news:WhYQf.15969$733.13650@tornado.texas.rr.com...

"Richard Harris" <none@none.com> wrote in message
news:dv1haa$bl3$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
Hi,
I have a plan for a PIC project but im not sure about the acuracy
that
can be achieved with a PIC.
Basicly I will be using a number of dealy routines but I need the PIC
to run
for 2 months and it must not lose more than 2 minutes per week. I
intend to
run it at 4MHz And the temperature should be fairly steady (code),
Should this be possible?

That's about 200 parts/million so yes,a 4MHz crystal will do the job
nicely, but it will burn up a couple of mA. Do you really need that
much speed for your application? You could run it from a 32,768Hz watch
crystal and run continuously (without sleeping) for months (if not
years) from AA cells. In either case, sleeping would increase your
battery life.

Also a question about relays, my understanding is you can use them to
switch
a high voltage from a low votage triger, and that you can use them as
a
simple switch, you aply voltage to one side and the other side
contacts. Is
this the case?

Pretty much, but a PIC isn't going to be able to directly drive much of
a relay. You'll need a driver transistor of some sort for most relays.
How much voltage are you wanting to switch? A MOSFET may be the way to
go instead of the relay.

Thanks for your time, any help is much appreciated.

 

[JoeSP]

"WIlly Ci" <hsinhsin@comcast.net> wrote in message
news:csWdnRGDe4v8jFDeRVn-og@comcast.com...

thanks
found this online
http://www.compsys1.com/support/docs/ELbacklight_Guide.pdf



"Dan Hollands" <dhollan3@rochester.rr.com> wrote in message
news:%BTyf.74030$XJ5.17488@twister.nyroc.rr.com...

"WIlly Ci" <hsinhsin@comcast.net> wrote in message
newsYmdnVS1JYlwX1beRVn-rA@comcast.com...
hi everyone,

I have a electoric handhold sudoku game system,
is there any easy way to build at backlit for the LED screen?

thanks
Will

Seems like a hell of a lot of trouble. I'd just use one of those clip-on
book reading lights.

 

[Jasen Betts]

On 2006-03-12, Richard Harris <none@none.com> wrote:

Hi,
I have a plan for a PIC project but im not sure about the acuracy that
can be achieved with a PIC.
Basicly I will be using a number of dealy routines but I need the PIC to run
for 2 months and it must not lose more than 2 minutes per week. I intend to
run it at 4MHz And the temperature should be fairly steady (code),
Should this be possible?

if you use a crystal for the clock that could work.

Also a question about relays, my understanding is you can use them to switch
a high voltage from a low votage triger, and that you can use them as a
simple switch, you aply voltage to one side and the other side contacts. Is
this the case?

yes. get a relay and some flashlight bulbs and have a play.

Bye.
Jasen

 

[Alexander]

"Richard Harris" <none@none.com> schreef in bericht
news:dv33me$9u7$1@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com...

Hi,
Ok me made a circuit diagram that i think is as simple as it can
possibly
be.

http://www.synios.com/Circuit1.jpg

Does this look ok?

The technical data sheet on the pic states that it will operate at
12uA @
32kHz 2.0V typical.
So that is about uA = 0.000001(micro) * 12 = 0.000012 Amp hour

Timer Oscillator Current 1.2uA @ 32kHz 2.0V typical.
So that is about uA = 0.000001(micro) * 1.2 = 0.0000012 Amp hour

0.000012 + 0.0000012 = 0.0000132 Amp hour

0.0000132 * 24 (hours in day) = 0.0003168
0.0003168 * 60 (days in 2 months) = 0.019008 Amp

So I would need 0.02 Amp battery then to run the pic for 60 days.

It does seem a little to impressive, have I made some big mistake
here ?

Lastly, it seems that a relay is not such a good idea, because it
uses to
much current to operate.
I know that the push button switches i need to operate simply
contacts two
terminals when the button is
pushed and that the device is running of 3.6V also the current
passing
though cant be very much.
What would be the simplest way of operating the switch from the
output pin
of a pic? would a Mosfet do the job? and any info on how to do this.

Thank you for your time, it is very much appreciated..


RJH




"Richard Harris" <none@none.com> wrote in message
news:dv1haa$bl3$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
Hi,
I have a plan for a PIC project but im not sure about the
acuracy that
can be achieved with a PIC.
Basicly I will be using a number of dealy routines but I need the
PIC to
run
for 2 months and it must not lose more than 2 minutes per week. I
intend
to
run it at 4MHz And the temperature should be fairly steady (code),
Should this be possible?

Also a question about relays, my understanding is you can use them
to
switch
a high voltage from a low votage triger, and that you can use them
as a
simple switch, you aply voltage to one side and the other side
contacts.
Is
this the case?

Thanks for your time, any help is much appreciated.





I don't have much experience with solid state relays, maybe they

consume less power.

Alexander

 

[Arabel]

Take a look at this site , what you have seen was not US main voltage, but
a high voltage transformer of a monitorset or TV. Tesla coils can also be
used.
It works with a voltage of about 20.000 Volts!!! more or less, and creates a
ION-wind which lift the device into air.
Try google for words like "powering a lifter" tesla coils etc...
http://jnaudin.free.fr/html/lftbld.htm


grtz





"Richard Harris" <none@none.com> wrote in message
news:duhn48$msk$1@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com...

Hi, this is a little long.
I was watching a TV program about UFO's as there was nothing else on TV,
it
was very comical and amusing but then there was a 30 second clip of some
guy
that explained something and then showed an experiment. It got my
attention
and curiosity, would like to know if anyone has any information about what
is described below and if its true or not, as they say you cant believe
everything you see on TV.

The guy showed a device which was simply a circular coil of wire wraped
around about 240 times at a diameter of 4 inches, it had no core, just
taped
into a circle. It was not insulated either, not sure what gage wire it
was,
anyway, the two ends of the coil was attached to a US style mains plug,
the
guy plugged this into a US mains outlet which I believe is 110V 60HZ AC,
and
the coil of wire levitated in the air, there was no metal core or
anything,
it was not electromagnetism holding the coil in the air, but it just
floats
in the air! Now the only thing I would expect the coil to do would be to
generate a load of heat and a magnetic field. Is this for real? Any idea
what is going on?

I did not want to try this, for a number of reasons, one I have 240V
supply,
two my fuse box would most likely trip soon as the device is plugged in.

I did try google for information on this and came up with nothing like it.

Thanks.

 

[David]

Jason,

I would not consider the request vague but more as a general request.

A general request will hopefully provide a range of possible solutions
for consideration and give a reasonable idea of what's "out there" to
supplement my web search.

Regards

David

 

[Don Kelly]

----------------------------
"Arabel" <arabel@home.nl> wrote in message
news:dv4i5n$lnh$1@news4.zwoll1.ov.home.nl...

Take a look at this site , what you have seen was not US main voltage,
but
a high voltage transformer of a monitorset or TV. Tesla coils can also be
used.
It works with a voltage of about 20.000 Volts!!! more or less, and creates
a
ION-wind which lift the device into air.
Try google for words like "powering a lifter" tesla coils etc...
http://jnaudin.free.fr/html/lftbld.htm


grtz

So? No big deal and definitely not a way to get a practical device.
Variation of the old corona pinwheel and the practical application of
electrostatic speakers. Efficiency low, power/weight ratio very high.
--

Don Kelly @shawcross.ca
remove the X to answer

>

 

[John Fields]

On Wed, 15 Mar 2006 04:17:27 +0000 (UTC), "Richard Harris"
<none@none.com> wrote:

Hi,
how much do you charge per hour for advice and your skills in electronics?

---
$125.00
---

Thanks

---
Sure.

--
John Fields
Professional Circuit Designer

 

[Richard Harris]

"John Fields" <jfields@austininstruments.com> wrote in message
newsvuf12hotcnkat1f1iu1doo6b9sh8u197b@4ax.com...

On Wed, 15 Mar 2006 04:17:27 +0000 (UTC), "Richard Harris"
none@none.com> wrote:

Hi,
how much do you charge per hour for advice and your skills in
electronics?

---
$125.00
---

Thanks

---
Sure.

--
John Fields
Professional Circuit Designer

ah great, will contact you in a few weeks when I have got all my stuff
together.

Thanks

 

[JeffM]

...modifying it from a 1.5 V battery to a 9V battery.
GuitarPsych

Seems like a dumb idea. A cell is much cheaper than a battery.
What advantage could there possibly be?

 

[Jasen Betts]

On 2006-03-16, GuitarPsych <none@test.com> wrote:

These are reasons just off the top of my head:

1) To go through the process just to learn.

this Is a good reason

2) To standardize all my effects pedals so I only have to carry 1 type
of extra battery, therefore minimizing carrying space and weight and
minimizing the chance I will be out of the one I need.

another good reason.

3) The standardization will also eventually allow me to work on a
project that allows all my pedals to run on a power supply that accepts
multiple pedals. The power supply works with pedals expecting 9V. I am
unclear if it would work with pedals expecting 1.5 V... I have my
doubts, therefore the conversion project.

this could prove more challenging than it seems at fiirst glance
often interconnected DC powered devices can't be powered in parallel
due to them using different signal ground potentials.

4) The 1 AA battery dies quickly.

the 9V typically contains less energy and costs many times as much
it will die faster, possibly much faster.

so that's two for and two agaist.

Bye.
Jasen

 

[Daniel]

Gareth Edwards wrote:

Hi

Can anybody explain to me exactly how this circuit functions, what it does,
and why were the components chosen i.e. how were the resistor values
calculated etc.
Where it says "solar +ve", this is the positive pole of a small solar panel.
The circuit works on 2 AA batteries in series.
L1, L2, R1, R2, and R3 are all resistors.
The capacitor is a 101. 100pF ceramic disc type.
Two transistors are S8050 type.
Diode is a 1N5819.

Thanks for any help.

Gareth, any chance you can reduce the size of the circuit Diagram?
Trying to work out what's going on, when you can only see about one
sixth of the circuit at a time, is pretty difficult. Printing it out is
worse yet.

Daniel
*** Free account sponsored by SecureIX.com ***
*** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com ***

 

[GuitarPsych]

I'd rather not make this about a debate as to whether it's a good idea
overall. I may in fact not actually do the conversion. Regardless, I
would just like to know how to go about doing it, IF I chose to.

Jasen Betts wrote:

On 2006-03-16, GuitarPsych <none@test.com> wrote:

These are reasons just off the top of my head:


1) To go through the process just to learn.


this Is a good reason


2) To standardize all my effects pedals so I only have to carry 1 type
of extra battery, therefore minimizing carrying space and weight and
minimizing the chance I will be out of the one I need.


another good reason.


3) The standardization will also eventually allow me to work on a
project that allows all my pedals to run on a power supply that accepts
multiple pedals. The power supply works with pedals expecting 9V. I am
unclear if it would work with pedals expecting 1.5 V... I have my
doubts, therefore the conversion project.


this could prove more challenging than it seems at fiirst glance
often interconnected DC powered devices can't be powered in parallel
due to them using different signal ground potentials.


4) The 1 AA battery dies quickly.


the 9V typically contains less energy and costs many times as much
it will die faster, possibly much faster.

so that's two for and two agaist.

Bye.
Jasen

 

[Jasen Betts]

On 2006-03-16, Daniel <dxmm@nospam.albury.net.au> wrote:

Gareth, any chance you can reduce the size of the circuit Diagram?
Trying to work out what's going on, when you can only see about one
sixth of the circuit at a time, is pretty difficult. Printing it out is
worse yet.

I see you're using linux, install xzgv and use that to view the pic, press z
to zoom out.

Bye.
Jasen