555 timer problem

[randomname]

I'm working on the "time fountain" project and have run into probably
the last of my problems. Here is the circuit (just strobing LEDs, and
a motor):

+6V
+------+ |
+6V>--+--[1N4001>]--+------|Vcc | [LED]
| |+ | | |K
| [1000µF] | OUT|----+
| | | |
GND>--|-------------+------|GND 5|--[.1uf]--|GND
| +------+
|
|
+--------------------------------------+
| |
| +----+----+
| | |
| [1N4001] [MOTOR]
| | |
| +------+ +----+----+
+6V>--+--[1N4001>]--+------|Vcc | |
|+ | | C
[1000µF] | OUT|---[R]--B
| | | E
GND>----------------+------|GND 5|--[.1uf]--|
+------+ GND

The top timer just controls strobing LEDs, and appears to be working
fine (though I have no real means to test it).

The bottom timer, however, gives me problems. I'm using a 1uf cap, 1K
for uptime, and 1K for downtime. (The configuration is such that one
resistor controls the cap charge, the other controls the discharge)

The motor is a tiny submersible 3vdc water pump. The problem is that
the frequency of the 555 timer will alternate. Ive hooked up a piezo
in parralel to the motor, so I can hear the frequency of the timer. (I
dont have an oscilloscope)

It will be high for a few seconds, then dip low for a few seconds, then
go back high. When this happens, it changes the RPMs of the motor
which changes the flow of water -- I need a constant flow of water. I
just need the motor to run steady at a certain rate, which it does, but
only for short bursts of time.

I need the 555 to stay as constant as possible... but for some reason
the 555 timer is giving me a hard time. Any suggestions? Thanks a
lot!

-sam


Another note: when I first turn on the rig it will work fine for a
minute or two, then it will start to give me problems. Don't know if
that helps.

 

[John O'Flaherty]

I'm working on the "time fountain" project and have run into probably
the last of my problems. Here is the circuit (just strobing LEDs, and
a motor):

+6V
+------+ |
+6V>--+--[1N4001>]--+------|Vcc | [LED]
| |+ | | |K
| [1000µF] | OUT|----+
| | | |
GND>--|-------------+------|GND 5|--[.1uf]--|GND
| +------+
|
|
+--------------------------------------+
| |
| +----+----+
| | |
| [1N4001] [MOTOR]
| | |
| +------+ +----+----+
+6V>--+--[1N4001>]--+------|Vcc | |
|+ | | C
[1000µF] | OUT|---[R]--B
| | | E
GND>----------------+------|GND 5|--[.1uf]--|
+------+ GND

The top timer just controls strobing LEDs, and appears to be working
fine (though I have no real means to test it).

The bottom timer, however, gives me problems. I'm using a 1uf cap, 1K
for uptime, and 1K for downtime. (The configuration is such that one
resistor controls the cap charge, the other controls the discharge)

The motor is a tiny submersible 3vdc water pump. The problem is that
the frequency of the 555 timer will alternate. Ive hooked up a piezo
in parralel to the motor, so I can hear the frequency of the timer. (I
dont have an oscilloscope)

It will be high for a few seconds, then dip low for a few seconds, then
go back high. When this happens, it changes the RPMs of the motor
which changes the flow of water -- I need a constant flow of water. I
just need the motor to run steady at a certain rate, which it does, but
only for short bursts of time.

I need the 555 to stay as constant as possible... but for some reason
the 555 timer is giving me a hard time. Any suggestions? Thanks a
lot!

Maybe if you could post the exact circuit of the timer that controls
the motor, with all the parts and connections...

 

[default]

The motor is a tiny submersible 3vdc water pump. The problem is that
the frequency of the 555 timer will alternate. Ive hooked up a piezo
in parralel to the motor, so I can hear the frequency of the timer. (I
dont have an oscilloscope)

It will be high for a few seconds, then dip low for a few seconds, then
go back high. When this happens, it changes the RPMs of the motor
which changes the flow of water -- I need a constant flow of water. I
just need the motor to run steady at a certain rate, which it does, but
only for short bursts of time.

I need the 555 to stay as constant as possible... but for some reason
the 555 timer is giving me a hard time. Any suggestions? Thanks a
lot!

Maybe not what you are after, but if I were trying for a precise
amount, particularly individual drops of liquid, I'd look into
chemical metering pumps. I forget the name of the manufacturer, but
someone makes a tiny (Ice Cube size) solenoid pump that is capable of
very precise delivery with each stroke of the solenoid.

I saw the thing at a pharmaceutical instrument trade show. Vicor may
be the name of the company - but searching didn't turn up hits on a
pump. Slick little pump - they had it making precise timed air
bubbles and timed droplets of one fluid in another (immiscible) fluid
(like those wave tank thingees they sell to executives to put on their
desks, or the old lava lamp)

From what you are saying, I get the idea that you are dealing with a
centrifugal type (impeller) pump (similar to a car windshield washer,
or boat bilge pump). For precise delivery a positive displacement
pump will work much better - each revolution or stroke of a piston
delivers a known amount of fluid and if you stop up the outlet the
pump stalls.

And if that is the idea - no pressure necessary - you could just use
your pump to pump up a liquid to a small reservoir and let it overflow
to maintain a constant head - then regulating the drips could be done
with a small needle valve or pinch valve on some tubing. Motor speed
of the pump isn't critical to delivery rate that way.

One solution, with the pump you have, if you want pressurized water,
may be to use it to pressurize a bladder tank similar to what well
water systems use. Sounds farfetched; don't it? On a miniature
scale, a balloon in a plastic enclosure. The bladder is in a rigid
enclosure and water can inflate the balloon compressing the air around
it (to provide a method of storing the small amount of pressure).
Balloon mechanically/magnetically opens a switch and shuts down the
pump until the pressure drops a little (or operates a linear
potentiometer that works the pulse width modulator on the 555?) slick
.. . .

Build your own pump? I cobbled together a pump from a loud speaker
and some strips of latex to use as check valves (ala aquarium pumps).
Mine was to provide puffs of air across a spark gap to quench the
spark - worked with 60 cycles to quench a 60 cycle spark. I only used
one check valve since the fluid in the tube (air in my case) had
inertia and once it was moving down the tubing it didn't want to come
back during the refill stroke of the voice coil. (and the length of
tubing was resonant at 60 hertz with air in it) - not for liquid but
it wouldn't be a big deal to use a sheet of thin latex (like a dental
dam from a drug store) to isolate the speaker cone from the fluid.
(latex is fine with water but doesn't like hydrocarbon oils).

It would be a piece of cake to modify an aquarium pump with a solenoid
driver instead of the magnet/AC coil they use. The parts are liquid
proof (plastic enclosure) Buena N diaphragm (from the looks of it) and
silicone rubber check valves. Vary the delivery by varying the stroke
with an adjustable stop on the solenoid driver so it limits the range
of motion.

Then you have Archimedes pumps, bucket pumps, etc if lifting water
without the need for pressure is the game.

Boggles the mind: don't it? I could have a lot of fun with this.

 

[randomname]

Maybe not what you are after, but if I were trying for a precise
amount, particularly individual drops of liquid, I'd look into
chemical metering pumps. I forget the name of the manufacturer, but
someone makes a tiny (Ice Cube size) solenoid pump that is capable of
very precise delivery with each stroke of the solenoid.

I saw the thing at a pharmaceutical instrument trade show. Vicor may
be the name of the company - but searching didn't turn up hits on a
pump. Slick little pump - they had it making precise timed air
bubbles and timed droplets of one fluid in another (immiscible) fluid
(like those wave tank thingees they sell to executives to put on their
desks, or the old lava lamp)

From what you are saying, I get the idea that you are dealing with a
centrifugal type (impeller) pump (similar to a car windshield washer,
or boat bilge pump). For precise delivery a positive displacement
pump will work much better - each revolution or stroke of a piston
delivers a known amount of fluid and if you stop up the outlet the
pump stalls.

And if that is the idea - no pressure necessary - you could just use
your pump to pump up a liquid to a small reservoir and let it overflow
to maintain a constant head - then regulating the drips could be done
with a small needle valve or pinch valve on some tubing. Motor speed
of the pump isn't critical to delivery rate that way.

One solution, with the pump you have, if you want pressurized water,
may be to use it to pressurize a bladder tank similar to what well
water systems use. Sounds farfetched; don't it? On a miniature
scale, a balloon in a plastic enclosure. The bladder is in a rigid
enclosure and water can inflate the balloon compressing the air around
it (to provide a method of storing the small amount of pressure).
Balloon mechanically/magnetically opens a switch and shuts down the
pump until the pressure drops a little (or operates a linear
potentiometer that works the pulse width modulator on the 555?) slick
. . .

Build your own pump? I cobbled together a pump from a loud speaker
and some strips of latex to use as check valves (ala aquarium pumps).
Mine was to provide puffs of air across a spark gap to quench the
spark - worked with 60 cycles to quench a 60 cycle spark. I only used
one check valve since the fluid in the tube (air in my case) had
inertia and once it was moving down the tubing it didn't want to come
back during the refill stroke of the voice coil. (and the length of
tubing was resonant at 60 hertz with air in it) - not for liquid but
it wouldn't be a big deal to use a sheet of thin latex (like a dental
dam from a drug store) to isolate the speaker cone from the fluid.
(latex is fine with water but doesn't like hydrocarbon oils).

It would be a piece of cake to modify an aquarium pump with a solenoid
driver instead of the magnet/AC coil they use. The parts are liquid
proof (plastic enclosure) Buena N diaphragm (from the looks of it) and
silicone rubber check valves. Vary the delivery by varying the stroke
with an adjustable stop on the solenoid driver so it limits the range
of motion.

Then you have Archimedes pumps, bucket pumps, etc if lifting water
without the need for pressure is the game.

Boggles the mind: don't it? I could have a lot of fun with this.

Wow! Thank you so much for providing me with all of these ideas. Ive
looked into the "positive displacement pump" solution and found just
the companies who might be able to help me out.. I just hope the cost
isn't absurd.

This page may contain the pump I'm looking for:
http://www.micropump.com/products/pumps/gear/

Do you think the Series GB pump would work? It seems like if I get
could the correct mL/rev and the right rev speed, I could get a perfect
drip!

Again, thank you so much!

-Sam

 

[default]

Wow! Thank you so much for providing me with all of these ideas. Ive
looked into the "positive displacement pump" solution and found just
the companies who might be able to help me out.. I just hope the cost
isn't absurd.

This page may contain the pump I'm looking for:
http://www.micropump.com/products/pumps/gear/

Yeah that looks like it (or its many cousins) could work.

Since you seem to be playing with 555's and battery power, I figured
this was more of a project to satisfy curiosity or for self
satisfaction (low budget toy).

And chemical metering pumps do tend to be expensive. They are made
for chemical, pharmaceutical, industrial applications and those people
have lots of money - and it ain't exactly a common item. They want
absolute accuracy, a pump that will run for a long time before
repairing, and usually in a harsh environment - that costs.

Farmers use them too, for fertilizer and livestock applications - but
it is still in a business context although they have less to spend.
Farm pumps are likely to be high volume types.

There the savings is usually one of chemicals that have a long life
when in a "stock" concentration and very short life when in a
"working" solution/dilution - the solution to the problem is mix the
two just before applying them.

What cost is absurd?

I haven't been following the whole thread, so I haven't kept up with
your quest. I was off for a week with the wife too . . . Is this,
are you building a water clock?

I had a deal where I had to fill and empty flasks in a robotic
chemical assay application. I found a really slick pump to do the
fill. Had to be within a fraction of a percent to volume.
Pharmaceutical company and money is no object (unless, of course, I
asked for a raise). Well anyhow this pump used compressed air on one
side of a piston and liquid to be pumped on the other. A stop (bolt
that ran into the end) adjusted the stroke length and delivery volume.
Very accurate and virtually foolproof and maintenance free. Looks
like it was made from schedule 80 PVC plumbing parts, with a little
machining and hardware. Check valves were off the shelf parts - one
way ball checks. Ingenuous and expensive but did the job
beautifully.

Another thought for accuracy and cheap easy to make (but not pulse
free) are peristaltic pumps. A hub spins with a motor. The hub has
rollers around the periphery. A piece of tubing is stretched around
~180 to ~270 degrees of arc against the rollers with enough force to
close the tubing where it touches the rollers (only works with low
modulus(?) tubing like silicone). I was using one to fill vials with
a 600 RPM drive and filled the vials to within a tenth of a percent,
using timing to turn the pump on and off.

You mentioned something about viscosity and drop size? I was a kid
and watching TV in the 50's sometime. There was a show called "You
Asked for It." Someone wanted to know what the largest drop size
was, and they sure produced a prodigious drop. They showed people
climbing up a ladder and dumping buckets into this large (6-8 foot
diameter) ring with about a three foot height. The "drop" formed at
the bottom of the ring and went into a huge tub.

Well this thing, if my memory is right, was just a ring with a very
fine mesh screen at the bottom and a layer of cloth resting on the
screen. They had to start it off carefully by wetting the cloth until
they had a few inches of water in it then just dumped buckets in it
until it drop 'd through the screen. You could see the drop forming
long before it dropped and it looked like it held a few hundred
gallons. The ring was formed with a "bell" opening where they were
pouring water, and it looked like the drop formed below with some
margin - like there was a rim or something that prevented the drop
from going out to the edge of the ring.

That was a long time ago. I was a kid. It was a black and white TV
and on an antenna - so perhaps there are gaps in my memory.

They didn't say, or I don't remember, if they had any way to increase
the surface tension of the water - I think not. I think the whole
idea/experiment was predicated on the same idea as used by aerators on
faucets.

Before someone jumps in my shit - aerators work mostly by keeping air
out of the pipe after the water is shut off - no air no drip (unless
the washer is bad). They also entrain air into the delivery for
esthetic reasons and help dissipate some off tastes that may be
present, due to volatile chemicals in the water.

I don't know if you can use that aerator thing I figure if accurate
delivery of water is paramount you don't measure by the drop, so a
drop must be necessary for a visual reason or for its impact when
falling onto something.

In absolute scientific terms a drop is a drop - but a drop at one
temperature will weigh more or less as the temperature and density
changes - if one were building a clock that needed a specific weight
for the mechanism, for instance.

 

[Homer J Simpson]

I haven't been following the whole thread, so I haven't kept up with
your quest. I was off for a week with the wife too . . . Is this,
are you building a water clock?

The Time Fountain
http://cre.ations.net/creation/44

Look at the video.

 

[James Thompson]

The Time Fountain
http://cre.ations.net/creation/44

Look at the video.

My solution and I tested it, was to use an aquarium air pump. But not to
pump air, so it pumps water. You take the chamber out of the air pump so it
will sit in the water basin. The tubing fits the outlet just like the air
line did. The magnet that was inside is removed from the swing arm and
attached to the rubber pump bulb. From there all that is needed is a coil
positioned close to the magnet. Each current pulse on the coil will produce
a drop of water. JTT

 

[default]

The Time Fountain
http://cre.ations.net/creation/44

Look at the video.

On dial up? Video? can they do that?

I'm sort of text . . . very slow dial up. Yes, when you think of
geographical area - not every one connects - and will never if
Congress (corporations) have a say. There are compensations.

I get the idea though. One wants a drip at precise intervals (?) and
then strobes it with light and cameras to make it look like the drip
(actually many drips) are in slow motion?

Should be easy with an LED, 555 and dripping spigot. But I haven't
never dun nothing like that so wouldn't no.

That seems really simple. Reservoir idea should be perfect for as
long as it needs to work for a camera - if this is for a
demonstration in a science exhibit, a metering pump and some anti
microbial solution in the working fluid would be better if school kids
were to see it.

What's the game? pictures or empirical discovery?

My computer security?: don't use Outhouse, Exploder, Flash Etc.

 

[Homer J Simpson]

On dial up? Video? can they do that?

It'll download and then run.

I'm sort of text . . . very slow dial up. Yes, when you think of
geographical area - not every one connects - and will never if
Congress (corporations) have a say. There are compensations.

I know there are parts of the US that still don't have phones, or where 300
baud is max dial up.

I get the idea though. One wants a drip at precise intervals (?) and
then strobes it with light and cameras to make it look like the drip
(actually many drips) are in slow motion?

Actually they detect the drops then fire the UV LEDs to sync with them. You
can make the drops 'run upwards' by tweaking the syncing.

 

[default]

My solution and I tested it, was to use an aquarium air pump. But not to
pump air, so it pumps water. You take the chamber out of the air pump so it
will sit in the water basin. The tubing fits the outlet just like the air
line did. The magnet that was inside is removed from the swing arm and
attached to the rubber pump bulb. From there all that is needed is a coil
positioned close to the magnet. Each current pulse on the coil will produce
a drop of water. JTT

Good job.

You can take a 10-32 bolt and use it to tap out a drill hole in
plastic. (helps to score it - the tap - with some longitudinal
gouges, but it isn't necessary - just to make a "proper" tap)

With the tapped hole, you can use those "drip irrigation" fittings in
the hardware store - then you can draw up liquid into the pump and
pump it out - no need to submerge the pump.- but I figure with 60
pulses per second timing should provide accurate delivery.

So why remove the magnet? I don't understand that. make it a
solenoid pump?

Or perhaps you got a pump that would make uniform drops?

Hey! Tell me more. are you driving it with 50/60 cycles, or driving
it with a solenoid? What pump are you using?

This is McGyver stuff,

 

[default]

It'll download and then run.


I know there are parts of the US that still don't have phones, or where 300
baud is max dial up.


Actually they detect the drops then fire the UV LEDs to sync with them. You
can make the drops 'run upwards' by tweaking the syncing.

Well it ain't that bad. I do's got's dialup. and at 50K.

My problem is I can't stay with one topic long enough to download.

Doubtless the pharmaceutical companies will have an answer for that -
with side effects like: runny nose, depression, suicidal impulses, and
death. I just ain't ready to go there.

Well you know this thing about making the drops run up? We were doing
that in the 60's and didn't use UV light (but did use zeon lamps which
do produce some UV).

It is called a "strobo tach" or."optical tach" these days - and they
are on the internet

 

[randomname]

Yeah that looks like it (or its many cousins) could work.

Since you seem to be playing with 555's and battery power, I figured
this was more of a project to satisfy curiosity or for self
satisfaction (low budget toy).

Well, I'd like the unit to cost as little as possible, because I'll
probably be making a bunch and giving them as gifts (very expensive
gifts). I might try to sell a few on eBay... considering the ones on
the webpage sold for $400 each, preordered (for 6-8 weeks in the
future, which is about now). So a pump under $50 would be great.

And chemical metering pumps do tend to be expensive. They are made
for chemical, pharmaceutical, industrial applications and those people
have lots of money - and it ain't exactly a common item. They want
absolute accuracy, a pump that will run for a long time before
repairing, and usually in a harsh environment - that costs.

I've looked on about 20 of these chemical/pharmaceutical/misc "fluidic
specialists" websites and found lots of suitable pumps.. but only one
site had a listed price (I've 'applied' to all the others, with as best
specifications as I could.)

Perhaps you could help me with this. Take a look and read their
descriptions:

http://www.hargravesfluidics.com/air_pumps.php (look for the CTS
models)
and
http://www.hargravesfluidics.com/liquid_pumps.php

The store for the CTS pumps is here:
http://www.hargravesfluidics.com/store_cts.php
and for the liquid is here:
http://www.hargravesfluidics.com/store_ltc.php

The LTC pumps cost double, and need at least 12volts. So I've ruled
them out.

However, the CTS pumps look like they could work. Especially the "low
flow" pumps at the bottom. I've measured the flow row of my fountain
when it drips at an optimal rate, and it turns out to be about
..08mL/minute. I measured it by weighing a cup, filling it for a minute
with the perfectly dripping stream, then weighing it again. I'm
assuming my tap water/highliter liquid solution is approximately 1g/ml.

Anyway, the problem is the CTS line of pumps doesn't explicitly say it
is meant for water. I'm wondering it will work anyway. I sure hope
so, because I'd love to order one right now and get this thing working
and very stable. I'd love to get rid of this valve and replace it with
just controlling the PWM. Which leads into my next question, PWM
should work the same with these pumps, right? It won't adversely
effect performance, will it?

And yet another question.. will the pulsation of one of these pumps
affect the unit? I mean, do you think it will vibrate enough to shake
the whole foutain and cause some disruption of the drops? I noticed
they work with a weight off the shaft of the motor which seems like it
will cause some wobble. I'm assuming that since it's so small it won't
do much.

On a side note, I found it astonishing how well these pumps react to
pressure! They can pump water really high for being so small. My
little impeller pump here has such a huge drop-off when the height of
the fountain is raised. But I guess thats the principal behind
"positive displacement," theres no way for the water to go but out the
pump.

I haven't been following the whole thread, so I haven't kept up with
your quest. I was off for a week with the wife too . . . Is this,
are you building a water clock?

I hope you check out the video.. it shouldn't take longer than 5
minutes to load.

You mentioned something about viscosity and drop size? I was a kid
and watching TV in the 50's sometime. There was a show called "You
Asked for It." Someone wanted to know what the largest drop size
was, and they sure produced a prodigious drop. They showed people
climbing up a ladder and dumping buckets into this large (6-8 foot
diameter) ring with about a three foot height. The "drop" formed at
the bottom of the ring and went into a huge tub.

Well this thing, if my memory is right, was just a ring with a very
fine mesh screen at the bottom and a layer of cloth resting on the
screen. They had to start it off carefully by wetting the cloth until
they had a few inches of water in it then just dumped buckets in it
until it drop 'd through the screen. You could see the drop forming
long before it dropped and it looked like it held a few hundred
gallons. The ring was formed with a "bell" opening where they were
pouring water, and it looked like the drop formed below with some
margin - like there was a rim or something that prevented the drop
from going out to the edge of the ring.

That was a long time ago. I was a kid. It was a black and white TV
and on an antenna - so perhaps there are gaps in my memory.

They didn't say, or I don't remember, if they had any way to increase
the surface tension of the water - I think not. I think the whole
idea/experiment was predicated on the same idea as used by aerators on
faucets.

I'd love to learn how to make bigger drops using this method. I'm
content with the current drop size, though. I might upgrade it by
putting a piece of McDonalds straw (aka soda-pipe) at the end, since
its much wider.

As per the pump made from the aquarium pump... I'll look into this but
I'd prefer a plug-and-play solution at this point. I'm hoping one of
the several pump places I've contacted will be friendly enough to be
like "we've got just the right pumpt for you... and it's a very common
one. It'll be $30." We'll see, and I'll definitely keep you all
posted.

Again, thanks so much for keeping up with this!

-sam

 

[default]

Anyway, the problem is the CTS line of pumps doesn't explicitly say it
is meant for water. I'm wondering it will work anyway. I sure hope
so, because I'd love to order one right now and get this thing working
and very stable. I'd love to get rid of this valve and replace it with
just controlling the PWM. Which leads into my next question, PWM
should work the same with these pumps, right? It won't adversely
effect performance, will it?

Don't have a lot of time to devote to this now
Check out:
http://www.allelectronics.com/cgi-bin/category.cgi

Looks like the CTS and is surplus. They call it an air pump but they
could be wrong - at $15 you could experiment

Air pumps will work with other fluids if the materials are compatible
- water is way more viscous too, the pump would have to turn slowly to
pump water.

Other sites for cheap pumps, when they have them (surplus)

http://www.labwarehouse.com/lw/

http://www.sciplus.com/search.cfm? Look for pumps

www.surpluscenter.com

They all have interesting paper catalogs too.

 

[Homer J Simpson]

Well, I'd like the unit to cost as little as possible, because I'll
probably be making a bunch and giving them as gifts (very expensive
gifts). I might try to sell a few on eBay... considering the ones on
the webpage sold for $400 each, preordered (for 6-8 weeks in the
future, which is about now). So a pump under $50 would be great.

Look at model railroad accessories (like Faller or Vollmer). ISTR a tiny
solenoid pump that ran waterwheels on some models.

 

[default]

Anyway, the problem is the CTS line of pumps doesn't explicitly say it
is meant for water. I'm wondering it will work anyway. I sure hope
so, because I'd love to order one right now and get this thing working
and very stable. I'd love to get rid of this valve and replace it with
just controlling the PWM. Which leads into my next question, PWM
should work the same with these pumps, right? It won't adversely
effect performance, will it?

And yet another question.. will the pulsation of one of these pumps
affect the unit? I mean, do you think it will vibrate enough to shake
the whole foutain and cause some disruption of the drops? I noticed
they work with a weight off the shaft of the motor which seems like it
will cause some wobble. I'm assuming that since it's so small it won't
do much.

I'm guessing the CTS pump wasn't intended for liquid - that isn't to
say it wouldn't work with water - I just don't know. The problem with
pumping liquid through an air pump is the density/viscosity is so much
higher that it effectively stalls the pump - can't move out the outlet
fast enough.

Air pumps can be used to pump water indirectly by filling a vessel
with water and using air to displace it. A three liter plastic soda
bottle is an excellent pressure vessel (one of the home brewers tested
a 20 ounce PET bottle to 125 PSI and it held without problems - I just
put sugar, water and yeast in one and my 20 ounce bottle was teardrop
shaped and held 40 ounces when it was finished fermenting - but it
didn't break)

You just need a stopper with two holes and a dip tube to go to the
bottom then use the air pump to pressurize the head space. 15 pounds
of pressure will raise water about 30 feet.

Vibration may not be a problem you won't know until you try. It is
very easy to just make a suspension so the vibration isn't coupled
into the drop tube. For aquarium pumps I just put springs to each of
the corners and mount it in a frame - I even used a similar technique
to mount an air compressor in an attic - built a wooden frame and
suspended it from the rafters on four springs (1/2 hp compressor with
air tank). No noise in the lab below. When it was on the joists it
made one hell of a racket.

You seem to be killing yourself with all this fixation on getting
uniform drop spacing. Why?

If you look at the original device - he uses a PIC (overkill in my
opinion) to trigger the strobe when a drop fell. That is easily done
with two 555's. Using the conductivity detector to trigger the first
timer to allow a delay, then a short time delay 555 to fire the
strobe.

The thing will work perfectly every time because the acceleration of
the drops as they fall is governed by gravity and is consistent (so
the strobe will always fire at the precise point in time when the drop
is at a fixed distance from the nozzle. If you want them to look like
they are moving upwards - that may still need consistent delivery to
make it look fluid.

It looks like U toob requires flash player. Flash player is spyware
in my opinion

- it defaults to leaving your camera and microphone open to sites you
visit (if you have a camera or microphone).

To change the privacy settings you have to visit a web site with Java
Script enabled so they can set the privacy settings you select, and
you have to trust that they do it.

They have something similar to web cookies - that were intended to be
non-removable tracking cookies.

See
http://internetweek.cmp.com/showArticle.jhtml?articleID=160400749

I won't have Flash player installed on my computer, and there is no
alternative - so I can't use U toob.

 

[default]

On 2 Oct 2006 01:57:37 -0700, "randomname" <[email protected]>
wrote:

http://www.allelectronics.com/cgi-bin/item/PMP-6/search/PRECISION_MICRO_AIR_PUMP_.html

Correct link to the pump


Sensidyne # AA060INSNF40VC2. Precision, miniature air pump. Operates
on 6 Vdc, 80 mA (no load). Minimum free flow, 1460 cc / min. Minimum
Vacuum @ dead head, 9.1" HG (307 mbar). 1.55" x 1.22" x 0.68." Ports
for 1/8" (3.2mm) ID tubing.
CAT# PMP-6

Your Price: $14.75 each

 

[randomname]

Sensidyne # AA060INSNF40VC2. Precision, miniature air pump. Operates

on 6 Vdc, 80 mA (no load). Minimum free flow, 1460 cc / min. Minimum
Vacuum @ dead head, 9.1" HG (307 mbar). 1.55" x 1.22" x 0.68." Ports
for 1/8" (3.2mm) ID tubing.
CAT# PMP-6

Your Price: $14.75 each

Thanks again for the info.

I've been browsing allelectronics to see how much it would cost to
build 10 of these babies, and it's incredibly cheap. I never bothered
to search or a pump! Can't believe they have it. I hope it can handle
water... I have a feeling it won't, though. Seems like theyd advertise
that it could be used for water.

I've ordered this pump, along with the tronics for building another
fountain. This time around I'm going to use a 556 timer instead of a
555, so that I only need 1 1000uF cap, and to make everything better
organized (especially since the breadboard I ordered has positive and
negative rails on both the top and bottom. Score!)

In the meantime, we'll see what these "fluidic professionals" say, if
they bother to reply to a non-company such as myself.

-sam

 

[randomname]

Look at model railroad accessories (like Faller or Vollmer). ISTR a tiny
solenoid pump that ran waterwheels on some models.

I'll look into that right now..

http://www.walthers.com/exec/productinfo/348-422319

and I've find this little guy for only $3.. there are no specs though.
Do you happen to know what voltage is the standard for these train
set-ups? Hopefully <6v DC.

Thanks,
-sam

 

[Homer J Simpson]

I'll look into that right now..

http://www.walthers.com/exec/productinfo/348-422319

and I've find this little guy for only $3.. there are no specs though.
Do you happen to know what voltage is the standard for these train
set-ups? Hopefully <6v DC.

Typically 12 - 20 VDC - but Marklin uses AC IIRC.

That looks like the pump - my memory is that it runs off AC - it kind of
'buzzes' at 60 cycles. This one is made in China.

http://www.ihc-hobby.com/cgi-bin/bsc.cgi?sn=9795F974U9491U74284998K9192HW4&id=42-2319

 

[randomname]

Today I purchased a wall transformer from the dollar store (liars -- it
was $3.59) that has 1.5, 3 4.5, 6, 9, and 12 volts, and works with 110
or 220 volt inputs, and provides 500mA of current.

So this replaces my 4 AA batteries, which would run weak after a couple
of hours. Strange thing is, when set to 6v it really makes my set-up
go crazy. The pump pumps way more liquid, and the strobe lights just
go crazy.. they flash brightly and irradically.

So I switched it to 3v and everything is fine. Pump runs very stable,
and the LEDs are steady and bright. It's been running for over an hour
completely stable (except for the normal hiccups and jitter caused by
my crappy pump). The wall transformer is just warm (about 115 F), so I
figure it's happy.

I wonder why I need to set it to 3v. If i switch it to 220v mode, I
need to crank it up to 12v for it to run about the same. If anyone can
explain this I'm all ears.

Oh well, it works!

-sam