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A REMOTE ALARM REPORTING SYSTEM

by Tom Petruzzellis

Start ý Under the Hood ý Building Tele-Alert ý Putting It To Work ý Customizing Your Tele-Alert System ý Sources and PDF

BUILDING THE TELE-ALERT

Construction of the Tele-Alert is quite straightforward (see Photo 1). First, youýll need to line up the circuit board with the parts layout diagram. Be sure the circuit board is facing you with the component side facing up as you begin placing parts into the circuit board. This is an important step, so take your time and make sure you are placing the components on the correct side of the circuit board before you begin soldering parts to the double-sided circuit board.

Photo 1ýThe Tele-Alert board prototype was constructed on a dual-sided glass-epoxied circuit board.

You can begin, by placing the resistors and capacitors on the board. Be sure to observe the correct polarity when installing the capacitors or the circuit will not work correctly. Integrated circuit sockets were installed for the ICs in the event the circuit needs to be serviced at some point in time. These sockets can now be installed.

Next, you can install the diodes and the LED. Once again, be sure to observe the correct polarity of the diodes when installing them. Now install the ceramic resonator and the MOV, followed by the transformer and regulator U5. Please note the orientation of the semiconductors before installing them. The integrated circuits usually have either a cut out or notch taken from the top of the chip or a small circle cutout at the top of the chip. Generally pin #1 is just to the left of the circle or cutout. Now install the male communication header J5, and the two optional enhancement female headers, J1 and J2.

Last, install the reset switch. The Tele-Alert circuit board measures 4 ý 2.5" and can be housed in a suitable plastic enclosure. Note that the basic Tele-Alert is only about 0.5" high, but if you intend to add optional modules, you should consider a taller enclosure to accommodate the optional circuit boards.

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