An output coming from a transducer is filtered,
signal conditioned and chopped. Finally it is converted
into square waves. The square wave is passed through
RLL multipliers. This output is gated by a precise
time base generated through piezo crystals and then
counted. This counts are displayed on bright LED's
.... It's nothing but R.P.M. with accuracy of±1
R.P.M.!!!
MEASURING RANGE
A) RLL circuitry requires minimum 2.5 pulses per
second i.e. 2.5 x 60 = 150 R.P.M. It's lower limit.
If more than one pulse is given in one rotation
then lower limit is reduced, eg if 2 pulses in one
rotation than 75 R.P.M. i.e. If n pulses per rotation
can give measurement of 150 * R.P.M.
B) 60 tooth gear wheel can give R.P.M. upto 10.
Specifications:
Input
Proximity switch, photo sensors,
voltage pulses, 60 tooth gear wheel etc.
RANGE
A)150
to 9,999 R.P.M. in normal case.
B) Lower limit can be reduced by factor n if n pulses
in one rotation.
C) With 60 tooth gear wheel 10 R.P.M.
ACCURACY
+
1 R.P.M.
DISPLAY
UPDATE
After
every second i.e. 1 second.
DISPLAY
4
digit bright easy to read seven segment L.E.D.
TIME
BASE
QUARTZ
CRYSTAL
PRINCIPLE
P.L.L.
Multipliers
SUPPLY
230
VAC ± 10%, 50 Hz.
BOX
SIZE
48H x 96W x 180D in mm modular design, or 72H x
72W or 96H x 96W
