Thanks Chuck! Very helpful. On Wed, Aug 30, 2017 at 11:04 AM, Chuck McCown <[email protected]> wrote:
> V out = Vin x [R1/(R1+R2)] > > So you are giving it 5 volts full scale and you need .1 volt to represent > full scale. > > V out/ V in = .1/5 or .02 > > Pick a R1. Normally telemetry inputs are pretty high impedance like 100K > or 1M so the divider resistance can use 1K as one of the resistances. > > So if R1=1K then 1k/.02 = 1K + R2 > 50K=1K + R2 > So R2=49K. > > Voltage in through the 49K resistor in series with the 1K resistor then to > ground. > > The telemetry would be fed from the junction between the two resistors and > ground. > > > *From:* Jesse DuPont > *Sent:* Wednesday, August 30, 2017 11:55 AM > *To:* [email protected] > *Subject:* Re: [AFMUG] Cost effective battery charging and monitoring > device > > So, R1 would be X Ohms and R2 would be X*.02 Ohms? > > *Jesse DuPont* > > Network Architect > email: [email protected] > Celerity Networks LLC > > Celerity Broadband LLC > Like us! facebook.com/celeritynetworksllc > > Like us! facebook.com/celeritybroadband > On 8/30/17 11:51 AM, Chuck McCown wrote: > > Forrest, quit working and come out and play with us.... > > *From:* Chuck McCown > *Sent:* Wednesday, August 30, 2017 11:49 AM > *To:* [email protected] > *Subject:* Re: [AFMUG] Cost effective battery charging and monitoring > device > > But you can use a voltage divider to convert the 0-5 volt to 0-.1 volt. > Two resistors. > > *From:* George Skorup > *Sent:* Wednesday, August 30, 2017 11:48 AM > *To:* [email protected] > *Subject:* Re: [AFMUG] Cost effective battery charging and monitoring > device > > No, the SiteMonitor shunt input is ±100mV nominal. > > On 8/30/2017 12:42 PM, Jesse DuPont wrote: > > Would these work on a SiteMonitor? They output 1-5V DC based on current > flowing through. > > https://flexscada.com/product/hall-effect-current-sensor-ac-75a-dc-100a/ > > *Jesse DuPont* > > Network Architect > email: [email protected] > Celerity Networks LLC > > Celerity Broadband LLC > Like us! facebook.com/celeritynetworksllc > > Like us! facebook.com/celeritybroadband > On 8/30/17 11:29 AM, George Skorup wrote: > > Yeah, about that. I wouldn't use those on 12VDC systems. Too much current. > I've burned up a couple of the 10A shunts on Traco BCMUs that were running > around 200W load on battery. 200/13 = 15 amps. Ungood. One site at about > 225W, first time it went to battery, the shunt went kaput after 10-15 > minutes and the site went down. > > I'm hoping Forrest comes up with some Hall effect stuff or even plain 20+ > amp shunts that can be used on the SiteMonitor's existing 100mv input. Hall > effect is nice because you don't have to be "in" the circuit. But I'll take > what I can get. > > On 8/30/2017 10:26 AM, Adam Moffett wrote: > > Yeah, up to 10 amp. > > > ------ Original Message ------ > From: "Chuck McCown" <[email protected]> > To: [email protected] > Sent: 8/30/2017 11:18:36 AM > Subject: Re: [AFMUG] Cost effective battery charging and monitoring device > > > I think Forrest has them on his site with the site monitors. > > *From:* Sam Lambie > *Sent:* Wednesday, August 30, 2017 9:15 AM > *To:* [email protected] > *Subject:* Re: [AFMUG] Cost effective battery charging and monitoring > device > > Parallel. Site Monitor! Now where can I get a shunt? > > On Wed, Aug 30, 2017 at 9:09 AM, Chuck McCown <[email protected]> wrote: > >> 4 batts in series or parallel? >> Shunt + sitemonitor would be a better way to go and you don’t have to >> write code. >> >> *From:* Sam Lambie >> *Sent:* Wednesday, August 30, 2017 9:06 AM >> *To:* [email protected] >> *Subject:* [AFMUG] Cost effective battery charging and monitoring device >> >> Hey all, >> I am getting away from using APC at a couple of our sites and right now I >> have installed a Tripp-Lite APS750 connected to 4 Deep cycle marine >> batteries for a total of 404 aH system. I'd like to be able to monitor the >> discharge rate of the batteries when power is out remotely. What have you >> guys been doing to that effect? >> >> I'm thinking a Pi and a shunt and some quick scripting classes on Python >> to put it all together... >> >> -- >> -- >> *Sam Lambie* >> Taosnet Wireless Tech. >> 575-758-7598 <%28575%29%20758-7598> Office >> www.Taosnet.com <http://www.newmex.com> >> > > > > -- > -- > *Sam Lambie* > Taosnet Wireless Tech. > 575-758-7598 <(575)%20758-7598> Office > www.Taosnet.com <http://www.newmex.com> > > > > > >
