Quasar 1019 User manual

QUASAR KIT No. 1019
CAR ALARM SYSTEM
GeneralDescription
This is a complete car alarm system that can be triggered by the vibrations caused by anyone
trying to break into a car, or alter natively by the small voltage drop that will be caused by any
courtesy light turning on when a door or the car's boot is opened, and also in direct mode that
the alarm is triggered when a certain point of its circuit is grounded. There is an entry time of
8", an exit time of 20" and the duration of the alarm (if it is not turned manually off by the user)
is 50". The alarm can control external devices (sirens, flashes, etc.) drawing a maxi mum
current of 3 A. If you wish to control heavier loads then you should use a relay as the output
device and control the loads through the relay.
Technical Specifications -Characteristics
Working voltage: 6-12V DC
Entry time: 8 sec
Exit time: 10 sec
Alarm time: 50 sec
How it Works
As it has already been mentioned the circuit provides the user with three time functions,
namely entry, exit and alarm time and also direct and pulse triggered alarm. The entry time is
controlled by the integrated circuit IC1 and the RC network R1-C2.
The transistor TR2 and its circuit which consists of C15, R16, R14, D2 & D5 is used as a
pulse detector which triggers the alarm if there is a sudden fluctuation of the supply voltage
which is an indication that the courtesy light -or some other light or apparatus -has been
turned on. The exit time is controlled by TR4 and the associated components D6, R8, R9, C4,
C6 & C7 and is 20 -30 seconds. The alarm duration is again controlled by an IC, the second
555 timer of the circuit and it depends upon the values of R5 and C8. The output from IC2 is
used to drive the output transistors TR1 and TR2 so that the circuit is capable to switch
heavier loads. The pin number 5 on the p.c. board can be used as a direct trigger for the
alarm as it will trigger the circuit immediately if it is connected to ground. Across point 5 and
the negative supply rail is where you can connect a vibration sensitive switch that closes
when it is moved, or push to brake switches that make contact when a door or the car's boot
are opened. Please keep in mind that the maximum permissible current
through the output of the circuit is 3 A. If the devices that you want to control are likely to draw
currents heavier than this, you should use the output from the alarm to control a relay and
then switch the various loads by means of the relay contacts.

Construction
First of all let us consider a few basics in building electronic circuits on a printed circuit board.
The board is made of a thin insulating material clad with a thin layer of conductive copper that
is shaped in such a way as to form the necessary conductors
between the various components of the circuit. The use of a properly designed printed circuit
board is very desirable as it speeds construction up considerably and reduces the possibility
of making errors. Quasar Kit boards also come pre-drilled and with the outline of the
components and their identification printed on the component side to make construction
easier. To protect the board during storage from oxidation and assure it gets to you in perfect
condition the copper is tinned during manufacturing and covered with a special varnish that
protects it from getting oxidised and also makes soldering easier. Soldering the components
to the board is the only way to build your circuit and from the way you do it depends greatly
your success or failure. This work is not very difficult and if you stick to a few rules you should
have no problems. The soldering iron that you use must be light and its power should not
exceed the 25 Watts. The tip should be fine and must be kept clean at all times. For this
purpose come very handy specially made sponges that are kept wet and from time to time
you can wipe the hot tip on them to remove all the residues that tend to accumulate on it. DO
NOT file or sandpaper a dirty or worn out tip. If the tip cannot be cleaned, replace it. There are
many different types of solder in the market and you should choose a good quality one that
contains the necessary flux in its core, to assure a perfect joint every time.
DO NOT use soldering flux apart from that which is already included in your solder. Too much
flux can cause many problems and is one of the main causes of circuit malfunction. If
nevertheless you have to use extra flux, as it is the case when you have to tin copper wires,
clean it very thoroughly after you finish your work. In order to solder a componentcorrectly
you should do the following:
Clean the component leads with a small piece of emery paper. Bend them at the correct
distance from the component's body and insert the component in its place on the board.
You may find sometimes a componentwith heavier gauge leads than usual, that are too thick
to enter in the holes of the p.c. board. In this case use a mini drill to enlarge the holes slightly.
Do not make the holes too large as this is going to make soldering difficult afterwards. -Take
the hot iron and place its tip on the component lead while holding the end of the solder wire at
the point where the lead emerges from the board. The iron tip must touch the lead slightly
above the p.c. board. -When the solder starts to melt and flow wait till it covers evenly the
area around the hole and the flux boils and gets out from underneath the solder.
The whole operation should not take more than 5 seconds. Remove the iron and leave the
solder to cool naturally without blowing on it or moving the component. If everything was done
properly the surface of the joint must have a bright metallic finish and its edges should be
smoothly ended on the component lead and the board track. If the solder looks dull, cracked,
or has the shape of a blob then you have made a dry joint and you should remove the solder
(with a pump, or a solder wick) and redo it.
Take care not to overheat the tracks as it is very easy to lift them from the board and break
them.
When you are soldering a sensitive component it is good practice to hold the lead from the
component side of the board with a pair of long-nose pliers to divert any heat that could
possibly damage the component.

Make sure that you do not use more solder than it is necessary as you are running the risk of
short-circuiting adjacent tracks on the board, especially if they are very close together.
After you finish your work cut off the excess of the component leads and clean the board
thoroughly with a suitable solvent to remove all flux residues that may still remain on it.
The construction of the alarm should present no difficulties thanks to the use of a well
designed and clearly marked printed circuit board. All the components are marked on the
component side of the board to help you place them correctly. Insert and solder first of all the
pins and the IC sockets taking care to align them correctly. Identify the resistors by means of
the colour bands on their bodies and solder them in their places, continue then with the
capacitors making sure that the electrolytic are inserted the right way round and finally solder
very carefully, so that you do not overheat them, the transistors and the diodes again making
sure that you insert them correctly. When you solder the components in their places do not
forget that this circuit is going to be used in the car and is likely to be subjected to a lot of
vibrations, changes of temperature and other rough treatment. With this in mind make your
joints as sound as possible because a lot of the circuit's reliability will depend on them. Use
onlymulti-stranded wire for your connections as this is less likely to brake under continuous
vibration and double check your soldered joints. If you are satisfied that everything is OK you
can insert the IC's in their sockets making sure that you orient them properly and that you do
not bend any pins as you insert them in their sockets. When everything is ready install the
alarm in the car making the following connections:
Pins 1 (+) & 2 (-) supply.
Pins 3 (+) & 4 (-) load output.
Pin No. 5 instant trigger (when it is connected to ground)
Connect a switch in series with the supply rail so that you can disable the alarm and hide it
somewhere in the car where it can be operated inconspicuously. A good idea is to use a key
switch which can be placed anywhere even outside the car provided you conceal its wiring.
Adjustments
This kit does not need any adjustments, if you follow the building instructions.
Warning
Quasar kits are sold as stand alone training kits.
If they are used as part of a larger assembly and any damage is caused, our company bears
no responsibility.
While using electrical parts, handle power supply and equipment with great care, following
safety standards as described by international specs and regulations.

If it does not work
Check your work for possible dry joints, bridges across adjacent tracks or soldering flux
residues that usually cause problems.
Check again all the external connections to and from the circuit to see if there is a mistake
there.
See that there are no components missing or inserted in the
wrong places.
Make sure that all the polarised components have been soldered
the right way round.
Make sure that the supply has the correct voltage and is connected the right way round to
your circuit.
Check your project for faulty or damaged components.
If your project still fails to work, please contact us for information about our Get-You-Going
service.
Schematic Diagram

Parts List
All components including printed circuit board, assembly instructions including schematics
and detailed parts list are supplied when you purchase the kit.
Ordering
For pricing info and online ordering please visit:
http://www.quasarelectronics.com/1019.htm
For further info please contact us by e-mail:
mailto: [email protected]
COPYRIGHT © 2003 Quasar Electronics Limited. All rights reserved. Reproduction of this document in whole or
in part in any form or medium without express written permission of Quasar Electronics Limited is prohibited.
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