magnetic switch activated alarm

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mikeymuss669
Posts: 3
Joined: Sun Jun 05, 2011 1:27 pm

magnetic switch activated alarm

Post by mikeymuss669 » Sun Jun 05, 2011 3:10 pm

Hello,
I assembled a circuit on a breadboard which is separated in 2 parts:
the right part is for generating an alarm which wails.
the left part is for starting the current flow to the first part when the magnet is detached from the reed switch.
Apparently the 1st part works (I get the wailing sound).
The second part almost works (the relay switches when I remove the magnet).
But no current passes through the negative part of the relay to the 1st part.
(I checked with the meter).
I attach a photo of the breadboard and the schematic, the components are :
three n2222 transistors
two n6027 programmable unijunction transistor
one 4001 diode
a dpdt 12v relay
a reed switch and a small magnet
(plus various capacitors and resistors)
The current is 12v dc
alarm-reedSw-breadB.jpg
alarm-reedSw-breadB.jpg (120.54 KiB) Viewed 5194 times
schematic-relay-reedSw.gif
schematic-relay-reedSw.gif (9.46 KiB) Viewed 5194 times
relay-reedSw.gif
relay-reedSw.gif (17.48 KiB) Viewed 5194 times

mikeymuss669
Posts: 3
Joined: Sun Jun 05, 2011 1:27 pm

Re: magnetic switch activated alarm

Post by mikeymuss669 » Wed Jun 08, 2011 11:02 am

I got it working.
See image.
The resistor on the far left is 1k
http://www.electronicspoint.com/attachm ... 1307530890

zac123
Posts: 5
Joined: Fri Jul 15, 2011 11:04 am

Re: magnetic switch activated alarm

Post by zac123 » Fri Jul 15, 2011 2:54 pm

i like this. is the plan to implement this in a building or just for fun?

zac

mikeymuss669
Posts: 3
Joined: Sun Jun 05, 2011 1:27 pm

Re: magnetic switch activated alarm

Post by mikeymuss669 » Fri Jul 15, 2011 5:25 pm

just for fun.
It's part of a tutorial I'm doing.
There are several simple (hem) circuits to make.

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