timer 555

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hadef

Joined: 31 Jan 2006
Posts: 4

31 Jan 2006 7:07 timer 555

how could i use the 555 timer to delay the coming signal for specific amoint of time

i mean i need a circuit that will alarm 2 minutes after the darkness is detected

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IanP

Joined: 05 Oct 2004
Posts: 6492
Helped: 1542
Location: West Coast

31 Jan 2006 7:53 Re: timer 555

Connect one 555 as 2-minute delay timer and another 555 as the alarm timer ..
The first timer is triggered by a photo-resistor (dark detector), the second timer is trigged by the first timer (alarm timer) ..
Examples of both circuits can be copied from:
http://www.uoguelph.ca/~antoon/gadgets/555/555.html

Regards,
IanP

ziyas

Joined: 16 Dec 2005
Posts: 45
Helped: 3

31 Jan 2006 19:18 Re: timer 555

it could help you :

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farshid.azhir

Joined: 05 Jan 2006
Posts: 2

01 Feb 2006 7:08 Re: timer 555

u need a monostable circuit so 555 timer is nice select for this
this circuit is adjustable 0sec to 8minute[img]http://h1.ripway.com/farshid-ar/monostable.bmp[/img]

vicky

Joined: 11 Aug 2004
Posts: 240
Helped: 19

03 Feb 2006 13:45 Re: timer 555

for this you have to connect it with the ldr tha a delay circuit and then a 555 timer it will gives you more accurate idea how the circuit hsould work

electronics_kumar

Joined: 29 Nov 2004
Posts: 664
Helped: 26
Location: Tamilnadu

10 Feb 2006 14:26 Re: timer 555

hadef wrote:

how could i use the 555 timer to delay the coming signal for specific amoint of time

i mean i need a circuit that will alarm 2 minutes after the darkness is detected

Convert 555 into monostable multivibrator..that will act as a delay circuit