Timer and counter

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jgueydan
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Timer and counter

Post by jgueydan » Sat Mar 09, 2002 2:31 pm

I need to make a timer that, when triggered from the positive output of an AND Gate, will provide a single shot, 1 sec pulse after 150 Seconds. Also, I need to make a counter that after three clock pulses (the same pulse used to drive the timer)will inhibit the input to an AND gate. The clock needs to normaly output a positive logic signal until the 3 pulses have come in. One more thing....I need to be able to reset the counter by way of a reset button. Thanks for any and all help you can give.<p>James

russlk
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Re: Timer and counter

Post by russlk » Sat Mar 09, 2002 6:33 pm

Your request can be accomplished with a 556 dual timer, 7474 dual D type flip flop, and some gating. I have shown AND gate followed by an inverter, but a NAND gate could have been used.
Image

russlk
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Re: Timer and counter

Post by russlk » Sat Mar 09, 2002 6:36 pm

Looks like the UBB code did not work. This is the URL of the circuit: http://geocities.com/russlk/onezero.gif<p>This does not work either, I guess email is the only way!<p>[ March 09, 2002: Message edited by: Russ
Kincaid ]<p>If you copy and paste the URL into the address bar, you can see the circuit. AND, when you come back to the BB, the circuit is there also!<p>[ March 09, 2002: Message edited by: Russ Kincaid ]</p>

jgueydan
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Re: Timer and counter

Post by jgueydan » Sun Mar 10, 2002 3:02 pm

Russ, I didn't see the reply you posted, so I appologize for the email I sent you earlier about the dual D flip-flop. If it's not to much trouble, could you send me the parts list...I'm having a bit of trouble reading the values. Thanks again for your help.

Dean Huster
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Re: Timer and counter

Post by Dean Huster » Mon Mar 11, 2002 8:21 am

Russ, if you have trouble posting pics here, try posting to the Poptronics "New" Electronics Bench board and reference to it from here. Their "New" board isn't the easiest to use for general postings, but it sure makes posting graphics easy. It's at http://www.poptronics.com/forums/electronic_bench/<p>Dean
Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).

R.I.P.

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