How about installing a potentiometer in series with the relay coil to vary the available voltage, i.e. the point it would drop out. Take reading of PPM and calibrate the scale of the knob on the pot.
Mike Ivan Anderson wrote: > Maybe a voltage (or current) comparator opamp with a fet switch? > If any one nuts one out, please let me know. > > Ivan. > > ----- Original Message ----- > From: "Robert L. Berger" <[email protected]> > To: <[email protected]> > Sent: Sunday, 16 July 2000 06:14 > Subject: Re: CS>Away too long > > > Hi Erwin; > > > > I haven't found out how to program a relay with a selectable window > for shut-off. > > > > Given me a schematic and I will paly with it. > > > > No doctor just a crotchy old guy' > > > > "Ole Bob" > > -- > The silver-list is a moderated forum for discussion of colloidal silver. > > To join or quit silver-list or silver-digest send an e-mail message to: > [email protected] -or- [email protected] > with the word subscribe or unsubscribe in the SUBJECT line. > > To post, address your message to: [email protected] > Silver-list archive: http://escribe.com/health/thesilverlist/index.html > List maintainer: Mike Devour <[email protected]>
