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Topic: Finding the right IC? (Read 529 times) previous topic - next topic

britesc

Hi,

I am looking for an IC that can handle a number of inputs then when requested send the specific input as an single output.
I think this is a series of input gates that open one when requested to allow data passage through the output.
I want to make a PCB that receives input from 5 or 6 sensors then upon request delivers the appropriate sensors info down the output line.

Can anyone please advise me if this is doable and if so where I should look for the IC.
And also if there is an easy way of finding IC's like a look-up table?
I also think I will need to change some of the data to be analog so that all data could be analog output.

Appreciate the help.

Thanks,
jB  8)
=====================================================
My Grandkids think I'm cool but, actually I'm partially sighted so sorry for any typos

Graynomad

At a guess I'd say you're looking for a multiplexer, try the 4051 or 4067.

But a lot depends on the exact circuit you are talking about, for a start what are the sensors?

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

Grumpy_Mike

Quote
And also if there is an easy way of finding IC's like a look-up table?

No, if you don't know what it is called then you can't look it up.
What you can do however is read the catalogues or web pages of major distribuitors like Farnell DigiKey Mouser and so on to see the sorts of chips that they sell.

britesc

Hi,

I want to take the temperature, current & voltage etc from each of my batteries used in an off-grid Photovoltaic, Wind Turbine bank.
Each battery is rated 2vdc 1200aH Lead Antimony Solid Plate Electrolyte, but sways up and down during charging, desulphating etc.
I have 24 so want a pcb per battery. ( 2 banks of 12) for a 24vdc array.
I hope to add in liquid level sensors etc.

Thanks,
jB  8)
=====================================================
My Grandkids think I'm cool but, actually I'm partially sighted so sorry for any typos

Graynomad

In a series string of batteries won't the current be the same in each cell?

You can use various analog sensors for the three parameters and mux them into the Arduino. For temp use one of the many sensors around, for voltage you can use a voltage divider (two resistors) at each cell to drop the (up to) 30V+ down to 5v for the Arduino.

However you will have to change the resistors (or even not use them at all) depending on the cell's position in the string. For example the first cell is nominally 0-2v and the last is 22-24v, a voltage divider that is appropriate for the last cell is not appropriate for the first.

______
Rob

Rob Gray aka the GRAYnomad www.robgray.com

britesc

Hi,

Strictly speaking Yes, but in practice No, as each battery is an independent entity that has various attributes such as, level of electrolyte, temperature, degree of sulphation, strength of electrolyte, etc. So to obtain the SOH of a battery (State of Health) I must accumulate as much data as possible then maintain a history trail, much like a weatherman. This will help predict ETOF (Estimated Time of Failure) so I can get the pennies ready for a replacement, also it will advise me which batteries are over or under performing in the banks so that they can be moved around.
It's all great fun, especially when you are partially sighted and disabled which was the instigator of the project...

I'm also on the lookout for external liquid level sensors (don't want the electrolyte to eat them) and the Holy Grail of a Specific Gravity Sensor.
And I want to make a small pulse generator (around 800Mhz) to work on the secondary sulphation.

Kind regards and thanks to all,

jB
=====================================================
My Grandkids think I'm cool but, actually I'm partially sighted so sorry for any typos

Graynomad

#6
May 23, 2012, 11:50 pm Last Edit: May 23, 2012, 11:53 pm by Graynomad Reason: 1
Very interesting. I live off solar and am in the processes of making a monitoring system, however I have a different approach.

I am working on a network of sensors to monitor all the aspects of the system. Apart from being much more versatile (it will do other things as well like show how level the RV is, switch security cameras, temp reading for the oven etc) it doesn't have any problems with noise because there are no analog signals running all over the place.

If you want to measure current at each cell you will need 24 shunts, that will get expensive although I have seen cheap ones on eBay. Also the voltage drop will add up with all those shunts. I suppose current transducers or hall-effect sensors would do the same job with no losses.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

britesc

Hi,

Thats exactly what I am doing too.
I have 4 linked Arduinos, with the mega as the master / web server. It also monitors gas production, flame etc, plus manages the cabinet, turning on fans and pet coolers when necessary.
2 Arduino UNOS.s manage a bank of 12 batteries each. The last manages the weather as I'm a nerd or geek or whatever the saying is now.
I will add 1 more to manage the PV cells, and 3.5Kw Wind Turbine (3 Phase).
As the whole lot is wired to my home network I can view the output as web pages.
I currently use a Debian Server as an SMS Gateway to sned alert messages etc.
I will switch that to an UNO running PPP interfacing to an MySQL database on the Debian Server as soon as I can.

At the moment I am busy making sensors boards for each battery so that only 1 input is required to the UNO for each battery.

I will keep updating my hit and miss progress.

Kind regards,

jB
=====================================================
My Grandkids think I'm cool but, actually I'm partially sighted so sorry for any typos

Graynomad

Quote
The last manages the weather

Can I have the code for that, I'm sick of all the rain we're getting.

Quote
nerd or geek or whatever the saying is now.

It sounds like either one is applicable.

Please keep us informed on progress.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

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