Re: Looking for a Low Cost On Delay Timer

["Guv Bob" <guvbob2003@xxxxxxxxxxxxxxxxxxxxxx>]

"unruh" <unruh@xxxxxxxxxx> wrote in message =
news:q5hRt.261777$Dd5.106684@xxxxxxxxxxx
> On 2013-08-21, Guv Bob <guvbob2003@xxxxxxxxxxxxxxxxxxxxxx> wrote:
> > "G. Morgan" <graham@xxxxxxxxxxxxxxxxx> wrote in message =
news:1jba199r3ropif879j9egfl40atou4jodi@xxxxxxxxxxxxxxxxxxxx
> >> Bob La Londe Wrote:=20
> >>=20
> >> >Check the specs of an Altronix 6060
> >>=20
> >> Or the 6062.  I think they are about $30.
> >>=20
> >> http://www.altronix.com/products/product.php?name=3D6062
> >>=20
> >>=20
> >>=20
> >> --=20
> >>=20
> >> They who can give up essential liberty to obtain a little temporary =
safety,
> >>  deserve neither liberty nor safety. - Ben Franklin
> >
> > Thanks guys.  Grainger has it for $30.   Before I head up there... =
this is not something that has to be done right away...   would putting =
together a circuit with this work?
> >
> > NTE955M Timer, (555 Type), 200 mA Iout, CMOS 8 DIP 1.20
> > http://www.alliedelec.com/search/productdetail.aspx?sku=3D70215850
> >
>=20
> A transistor /amplifier Ic, plus a capacitor, and a few resistors =
should
> do it. What time scales you you need? How fast does it need to switch =
on
> and switch off? What voltage tolerance do you need? -- ie if it is 11V
> out is that OK? What supply voltage do you have? Can the input drop to
> zero before 5 sec and what behaviour do you expect in that case?
> How accurate must the 5 sec be? etc

Hey unruh!

> A transistor /amplifier Ic, plus a capacitor, and a few resistors =
should
> do it. What time scales you you need?=20

Initially input voltage is zero.  When input goes to 12VDC, output =
should energize immediately to 12VDC, stay eneregized for 4-6 seconds, =
then drop to zero again.  When input goes to zero, output stays off =
until starts over.

> How fast does it need to switch on and switch off?
Within 1/2 second is fine.

> What voltage tolerance do you need? -- ie if it is 11V
> out is that OK? What supply voltage do you have?=20
Yes, 9-13 out is fine.  Supply is typically 11-12VDC.

> Can the input drop to zero before 5 sec and what behaviour do you =
expect in that case?
Yes it can.  Output should go on when input first goes on, then output =
should go off any time input is disconnected.

> How accurate must the 5 sec be? etc
4-6 seconds is fine.  Not critical.