Boat Electonic Project help For "Golden Newbie"

In retirement I am Improving my boat and need help with two projects .
The last one I did was in 1969 building a valve power amplifier! So,
any help will need to be jargon free,with diagrams , assume skill and
ability on my part -but little current knowledge.A Doctorate in
Science is my background.

Here goes Project1

I want to switch ,on/off, a 12v (ca 8 amp)pump via
a level sensor.The sensor has a 12v input permanently live. Two output
terminals are also normally live at 12v. As the liquid level rises
output1 goes to 0v . Further rise sets output 2 to 0v.At this point I
need to switch on the pump and maintain power whilst the level falls
first to the point at which output2 reverts to 12v and beyond this
level ,until output 1 reverts to 12v .The pump should then be switched
off and the whole cycle capable of being repeated.

Project 2

The mast head Anemometer (near antique!) generates
a pulse output at about 100mv and the frequency dependant on wind
speed.I need a circuit in which this pulse will switch a 12v few
milliamp supply to drive a modern tachometer thereby providing me with
a cheap,reliable analogue wind speed gauge. Here's the tricky bit.The
mast head unit runs at 0 to about 1000 rpm.The tacho needs 0-6000 rpm
for full range,so in the interval between two pulses from the mast we
need to generate a multiple number of equally spaced pulses to the
tacho. Oh yes,and the multiplication needs to be controllably variable
to allow calibration.

That's it . All help gratefully accepted.

Tony Marriott

 

[Glenn Ashmore]

dragmarriott@hotmail.com wrote:

In retirement I am Improving my boat and need help with two projects .
The last one I did was in 1969 building a valve power amplifier! So,
any help will need to be jargon free,with diagrams , assume skill and
ability on my part -but little current knowledge.A Doctorate in
Science is my background.

Here goes Project1

I want to switch ,on/off, a 12v (ca 8 amp)pump via
a level sensor.The sensor has a 12v input permanently live. Two output
terminals are also normally live at 12v. As the liquid level rises
output1 goes to 0v . Further rise sets output 2 to 0v.At this point I
need to switch on the pump and maintain power whilst the level falls
first to the point at which output2 reverts to 12v and beyond this
level ,until output 1 reverts to 12v .The pump should then be switched
off and the whole cycle capable of being repeated.

Seems like your float switch arangement is a bit over complicated. I
would rather see the logic reversed to prevent stray current from doing
electrolosis damage. If you went to 12V on high water you could just
cascade a couple of relays to provide the hysterisis you are looking for.

Project 2

The mast head Anemometer (near antique!) generates
a pulse output at about 100mv and the frequency dependant on wind
speed.I need a circuit in which this pulse will switch a 12v few
milliamp supply to drive a modern tachometer thereby providing me with
a cheap,reliable analogue wind speed gauge. Here's the tricky bit.The
mast head unit runs at 0 to about 1000 rpm.The tacho needs 0-6000 rpm
for full range,so in the interval between two pulses from the mast we
need to generate a multiple number of equally spaced pulses to the
tacho. Oh yes,and the multiplication needs to be controllably variable
to allow calibration.

Look into an LM2907 frequency to voltage converter. I am using them on
my watermaker control to sense engine RPM and display product water flow
from a turbine flow sensor. Fairly easy to set up following the app
notes, operate on 12V and the output can be adjusted to calibrate a
cheap volt meter.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

 

Glenn Ashmore <gashmore3@cox.net> wrote in message news:<NJZ8c.57$9g.44@lakeread04>...

dragmarriott@hotmail.com wrote:
In retirement I am Improving my boat and need help with two projects .
The last one I did was in 1969 building a valve power amplifier! So,
any help will need to be jargon free,with diagrams , assume skill and
ability on my part -but little current knowledge.A Doctorate in
Science is my background.

Here goes Project1

I want to switch ,on/off, a 12v (ca 8 amp)pump via
a level sensor.The sensor has a 12v input permanently live. Two output
terminals are also normally live at 12v. As the liquid level rises
output1 goes to 0v . Further rise sets output 2 to 0v.At this point I
need to switch on the pump and maintain power whilst the level falls
first to the point at which output2 reverts to 12v and beyond this
level ,until output 1 reverts to 12v .The pump should then be switched
off and the whole cycle capable of being repeated.

Seems like your float switch arangement is a bit over complicated. I
would rather see the logic reversed to prevent stray current from doing
electrolosis damage. If you went to 12V on high water you could just
cascade a couple of relays to provide the hysterisis you are looking for.

Project 2

The mast head Anemometer (near antique!) generates
a pulse output at about 100mv and the frequency dependant on wind
speed.I need a circuit in which this pulse will switch a 12v few
milliamp supply to drive a modern tachometer thereby providing me with
a cheap,reliable analogue wind speed gauge. Here's the tricky bit.The
mast head unit runs at 0 to about 1000 rpm.The tacho needs 0-6000 rpm
for full range,so in the interval between two pulses from the mast we
need to generate a multiple number of equally spaced pulses to the
tacho. Oh yes,and the multiplication needs to be controllably variable
to allow calibration.

Look into an LM2907 frequency to voltage converter. I am using them on
my watermaker control to sense engine RPM and display product water flow
from a turbine flow sensor. Fairly easy to set up following the app
notes, operate on 12V and the output can be adjusted to calibrate a
cheap volt meter.

Thanks for the suggestion,I'll look at the LM2907 and keep you
posted.I may be able to help you in your project in teak deck laying
and most types of surface coating. Please ask. regards A.G.M