power on delay circuit

[John O'Flaherty]

On Thu, 6 Mar 2008 12:53:18 -0800 (PST), JeffM <jeffm_@email.com>
wrote:

chitta wrote:
1.HIGH for 1 sec
2. LOW for 2 sec
3. HIGH permanently

If you MUST post the *same* question to MULTIPLE groups,
learn this technique:
http://www.google.com/search?q=cache:qHhBKJ-sXKYJ:en.wikipedia.org/wiki/Cross-post+adequately.answered+corrected+with.commas+individually+Disclaimers+*-*-*-marked-as-Read-in-ALL-*-groups+Newsgroups.line

That's pretty slick - I didn't know you could do that. It's the
highlight of my day.
--
John

 

[JeffM]

chitta wrote:

1.HIGH for 1 sec
2. LOW for 2 sec
3. HIGH permanently

If you MUST post the *same* question to MULTIPLE groups,
learn this technique:
http://www.google.com/search?q=cache:qHhBKJ-sXKYJ:en.wikipedia.org/wiki/Cross-post+adequately.answered+corrected+with.commas+individually+Disclaimers+*-*-*-marked-as-Read-in-ALL-*-groups+Newsgroups.line

 

[Chris]

On Mar 6, 3:45 am, chitta <chittaranjan.janard...@gmail.com> wrote:

Hi
  my name is chittaranjan.
  I need a waveform with power on as follows
1.HIGH for 1 sec
2. LOW for 2 sec
3. HIGH permanently

Please help me obtain this waveform without using any microcontroller

Read in fixed font or M$ Notepad:

|
| VCC
| +
| +|
| ---
| 1uF---
| | |\ ___
| .---o---|H>O--|<--|___|.
| | | |/ 22K |
| | .-. |
| - | |1M |
| ^ | | |
| | '-' |
| | | |
| === === |
| GND GND |
| 3/6 74HC14 |
| VCC VCC |
| + + |
| | | |
| | .-. |
| - | |3M |
| ^ | | |
| | '-' |
| | | |\ ___ | |\
| '---o--|H>O-->|--|___|-o--|H>O-
| +| |/ 220K | |/
| --- .-.
| 1uF--- 2.2 M| |
| | | |
| === '-'
| GND |
| ==| GND
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)

Requires 1/2 of a 74HC14 (or 74C14 if you're using a power supply of
more than 6VDC), 2 1uF caps, 5 resistors and four 1N914 diodes. If
your power supply takes more than 10ms. to charge up and discharge,
you can lose the two protection diodes.

Simple, not elegant or precise. Your timing on this may vary by quite
a bit.

Good luck
Chris

 

[chitta]

Hi
my name is chittaranjan.
I need a waveform with power on as follows
1.HIGH for 1 sec
2. LOW for 2 sec
3. HIGH permanently

Please help me obtain this waveform without using any microcontroller