in these above presentation i discuss about the importance of crystal tester

1. Presented
by
M.UDAY KUMAR

2.  Here is a simple circuit that can be used to
test a crystal before using it in a circuit. The
circuit is built around two BC547 transistors
(T1 and T2) and a few discrete components.
The oscillator circuit formed by transistor
T1, resistors R1 and R2, and capacitors C1
and C2 oscillates if a good crystal is
connected to the test points marked as CUT
(crystal under test). The output from the
oscillator is rectified by diode D1 and filtered
by capacitor C3. The positive voltage
appearing across the capacitor is fed to the
base of transistor T2, causing it to conduct

3.  INTRODUCTION
 CIRCUIT DIAGRAM
 WORKING
 COMPONENTS
 TRANSISTOR
 CAPACITOR
 OSCILLATOR
 ADVANTAGES
 DISADVANTAGES
 CONCLUSION
 REFFERENCE

4.  Most electronics project working with high
frequency utilizes crystal in order to
generate frequency as oscillator.
 It is used instead of coil. Coil can be checked
with multi-meter if there is any fault
 In order to solve this problem a simple
project using few components is designed
call crystal tester

5.  The principle of the inverse piezoelectric
effect.
 The piezoelectric effect refers to a change in
electric polarization that is produced in
certain materials when they are subjected to
mechanical stresses

7.  This circuit consist two NPN transistors,
 two diode with few passive component. The
crystal under test is combining with
transistor T1 which further work as oscillator.
 The combination of transistor T1, crystal
under test and capacitors C1 and C2 is work
as colpiitt oscillator.

8.  If the testing crystal is good then it works as
oscillator with transistor T1. The output of
oscillator is rectified and filtered by diode D1
and capacitor C2 respectively and given to base
of transistor T2.
 The signal given to base conduct transistor which
further glow the LED connected to the collector
through resistor R3. If the testing crystal is
faulty then LED1 does not glow.

10. Resistors
R1 = 27 KΩ
R2 = 1 KΩ
R3 = 560 Ω
Capacitors
C1 = 0.001 µF
C2 = 100 pF
C3 = 0.001 µF
C4 = 0.004 µF
Semiconductors
D1, D2 = 1N4148
T1, T2 = BC547
LED1 = Green
quartz oscillator

11.  BC547 is an NPN bi-polar junction transistor.
 Is commonly used to amplify current.
 A small current at its base controls a larger current
at collector & emitter terminals.
 BC547 is mainly used for amplification and switching
purposes. .
 Its equivalent transistors are BC548 and BC549.

12.  The transistor terminals require a fixed DC
voltage to operate in the desired region of its
characteristic curves.
 The input signal at base is amplified and
taken at the emitter. BC547 is used in
common emitter configuration for amplifiers

14.  A capacitor is a passive two-
terminal electrical component that
stores potential energy in an electric field.
 The effect of a capacitor is known
as capacitance.
 While some capacitance exists between any
two electrical conductors in proximity in
a circuit
 C=Q/V

15.  a capacitor is a component designed to add
capacitance to a circuit.
 The capacitor was originally known
as condenser or condensator

16.  A crystal oscillator is an electronic oscillator
that uses the mechanical resonance of a
vibrating crystal of piezo electric material
 It is used to create a electric signal with
prescise frequency
 Electronic symbol is

17.  Walter guyten cady first built quartz crystall
oscillator in 1921
Quartz crystal
oscillator
Tunning fork
crystall used
in quartz
watch

18.  A resistor is a passive two-terminal electrical
component .
 In electronic circuits, resistors are used to
reduce current flow, to divide voltages
 High-power resistors that can dissipate
many watts of electrical power as heat

19.  Very stable signal when used in an
oscillations
 Low levels of phase noise when used in an
oscillator
 When used in a filter it is possible to achieve
very high levels of selectivity
 Low cost: Basic crystals are
available at very reasonable costs.

20. • Size: A crystal relies on mechanical vibrations
for its resonant behaviour. As a result size
cannot be reduced easily
• Soldering: In view of their performance
soldering needs to be undertaken with care
observing maximum temperatures and
soldering times
• Fixed frequency: Although this can be an
advantage as well, a crystal has its own natural
resonant frequencies .These are suitable for
high frequency application.

21.  The idea for this crystal tester circuit sprung
out of the need of testing a large number of
oscillator crystals lying unused in a big hobby
box.It is useful to test even a complicated
crystal.

22.  http://www.theorycircuit.com/crystal-
tester-circuit/
 https://www.engineersgarage.com/electroni
c-components/transistor-bc547-datasheet
 https://www.google.co.in/search
 https://en.wikipedia.org/wiki/Capacitor
 https://en.wikipedia.org/wiki/Crystal_oscill
ator