SHOCK SENSORS

Shock sensors belong to the category of simple acceleration sensor that is mounted on a printed circuit board. These sensors are used to control vibrations, impacts and movements.

Features
·Very small,light-weight
Low cost
Wide frequency range
Hermetically sealed
Variety of types

Applications and size
For the function of the wrist watch with all kinds
(stop watch, runner watch, turns on light)
Steps counters, Calorie meter
Security sensor
Vibration sensor of the part feeder control equipment
Movement detection of the human body
(game equipment, medical equipment)
Bone conducted voice pickup for earplugs or helmets
Various switch function
Direction of sensitivity The vibration detection axis is formed by a straight line between the two terminals.
A(mm)
B(mm)
C(mm)
CR-03R
3
8
10
CR-035BM
3.5
13.5
10

Specifications
Model name
CR-03R　　【RoHS Compliant】
CR-035BM
Weight (Typ.) gm
0.2
 0.7
Charge Sensitivity (Typ.) pC/m/s2
( 0.260 )
1.1
Voltage Sensitivity (Typ.) mV/m/s2
0.87
2.5
Mounted Resonant Frequency (Typ.) kHz
9
3.5
Frequency Response Hz3dB * 1
fc1,000
 fc1,000
Capacitance (Typ.) pF
300
460
Measurement Range m/s2
5,000
500
Transverse Sensitivity (Max) %
20
20
Insulation Resistance (Min.) M
1,000
1,000
Temperature Range
-10+65
-10+60
Case Material
Nickel silver
Brass *2
* 1 : fc(lower cut off frequency) is determined by capacitance and amp's input impepance
* 2 :Sealed by epoxy

A preamplifier circuit (reference)
A charge amplifier may be used for this piezoelectric accelerometer. However, it is sometimes advantageous to use a voltage amplifier, since it is used for circuit board mounting. Since the vibration detecting feature is configured on the circuit board, the distance between sensor and amplifier circuit is short and constant. For this reason, sensors such as the model CR-03R, in which the voltage sensitivity is higher than the electric charge sensitivity, can be easily applied with a voltage amplifier.
ﾀdVoltage amplifier (example) Charge amplifier (± terminals) Charge amplifier (+terminal)
* fc = 1/2Rf•Cf
* The OP amplifier can contain an IC for JEET input: Hitachi HA1708D, NEC  PC821 or  PC831, T.I. TL071 or TL081, etc.
(conversion gain in mV/pC = 1000/Cf; Cf as pF).

Way of mount to circuit board
It always needs a shield like the figure
Solder the tip (Cum fixation)