dex
Joined: 24 Oct 2006
Posts: 1
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 Posted:
Tue Oct 24, 2006 8:57 am Post subject:
Help needed on Final Yr project! |
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hi to all. . . first post here. . . current third yr poly doing FYP and encountered some problem. . . Here's a brief overview of the project
name:fire alarm panel
budget: as low as possible as its an alarm for the residents
function: -detect smoke and fire through smoke and heat detector
-gives alarm when either smoke or heat is detected
-gives alarm when the detector are nt closed properly/open circuit
panel: -on/off switch
-three leds(Green-power on,Yellow-open circuit,Red-fire detected)
-silencer(to silence the alarm)
problem faced:
1) circuit runs on 24v,thus 2x12v rechargeable battery is needed.3 pin plug and a turn-down transformer circuit to bring down voltage and convert it to dc. though i know a transformer is needed to bring down voltage,full bridge rectifer to rectify,electro cap to smoothen and voltage regulator to regulate voltage. But nt realli sure of bridge rectifier/individual diode to use. Ani simulation website on this will ne of great help if ani
2)And since the battery need to be charged,i m nt sure whether to turn down voltage to 14v or 26v to charge it individually or to charge it together. suggestion needed thxs
3) A comparator circuit to start and stop charging when voltage of battery reaches below 21v or above 24v.
4)Ani one noes of a circuit or component to detect zero current?
5) Last problem but this is additional stuff,we had wanted to build a circuit to send sms to a desinated no with a predefined msg. Sourced the internet and found similar project at "http://www.wrankl.de/SMST4PIC/SMST4PIC.html" but nt sure how to start as tat PIC assemly language is alien to us. Ani pros on this willing to help?
Lastly,thx all 4 taking time out to read my long problem and hope help arrives fast thxs lotz in advance
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