help with easy circuit thanks

Feb 26, 2006 19 Replies

Hello



I need a simple circuit, so I ask you the simpliest way to do it :)



All I need to do is this. I have a Vin of 9volts (battery), I need to have a Vout=Vin for a few milliseconds (or even a few seconds is fine) and then Vout=0. So the goal is: when you connect the battery Vout=Vin for a few milliseconds/seconds (not important how long) and the Vout=0



Thanks



Put a relay coil across your input with the NC contacts feeding the circuit. Put battery across input, circuit gets full volts, relay energises and disconnects circuit.

"Big House" schreef in bericht news: snipped-for-privacy@v46g2000cwv.googlegroups.com...

These "simple" questions too often provide too little details to be answered. From the question "as is" the answer will be "use a pushbutton, an NO (normally open) type."

petrus bitbyter

well, it has to be it by itself without a switch... basically what I need is an automatic swtich...

thanks

well, it has to do it by itself! basically I need an automatic switch... Thanks

"Big House" schreef in bericht news: snipped-for-privacy@v46g2000cwv.googlegroups.com...

These "simple" questions too often provide too little details to be answered. From the question "as is" the answer will be "use a pushbutton, an NO (normally open) type."

petrus bitbyter

View in Courier: + +--[CAP]--+--O | | | O--->Vout | | +--> | [BATTERY] [COIL]- - -| | | +---------+----------->GND Cap is whatever it takes to keep the relay made (1000µF??) as long as you want when the battery gets connected to the cap.

Oops...

John Fields Professional Circuit Designer

Well,

That's exactly my point. *When* do you need this temporary Vout=9V? When the telephone rings? When the rain falls, or the nukes? When your mother in law arrives or when she departs? Sometime something has to activare that circuit but you did not mention anything in your question.

petrus bitbyter

would be too complex to explain, however let's say this.

- you plug the battery

- Vin=Vout for a short period of time

- after that, Vout=0 with Vin still connected.

That's it Thank you very much!

Hello

what I need is simply this:

t=0, Vin=0, Vout=0 t=1, Vin=9, Vout=9 t=2, Vin=9, Vout=0

where t is in seconds (even though I do not need it precise, just a chance of status in a "few moments") Thanks

When you connect the battery? As in a power-on-reset?

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

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when I physically put the wires on the battery... thanks

Are the changes in Vout driven by the input in the first case, and by time in the second case?

Ie. wait for Vin to go high, then Vout = high for 1 second?

Best regards, Spehro Pefhany

"it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com

Use John's earlier capacitor and relay option. Easiest so far.....

Ken

you need a one shot timer. look up 555 and one shot timer in google.

Real Programmers Do things like this. http://webpages.charter.net/jamie_5

--- :-)

maybe this'll make it even easier for him to visualize:

. +------------+-------->Vin . | + | . +--[CAP]--+ O . | | | O--->Vout . | | +--> | . [BATTERY] [COIL]- - -| . | | . +---------+----------->GND

-- John Fields Professional Circuit Designer

"Big House" schreef in bericht news: snipped-for-privacy@v46g2000cwv.googlegroups.com...

need a simple circuit, so I ask you the simpliest way to do it :)

need to do is this. I have a Vin of 9volts (battery), I need to

Vout=Vin for a few milliseconds (or even a few seconds is fine)

Vout=0. So the goal is: when you connect the battery Vout=Vin

milliseconds/seconds (not important how long) and the Vout=0

These "simple" questions too often provide too little details to be answered. From the question "as is" the answer will be "use a pushbutton, an NO (normally open) type."

petrus bitbyter

So far, to me, it sounds like the simplest thing would be just a capacitor:

VBatt + o---||----+-----o Vout + | [R] | VBatt - o---------+-----o Vout -

Cheers! Rich

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