This is the circuit of electromagnetic field sensor which can sense electromagnetic field
from 40Hz to 140Hz. The IC LF351 and associated components forms the
pick-up section. 1uH coil L1 is used for sensing the field and the IC1
performs the necessary amplification. If the picked electromagnetic field
is in the audio frequency range, it can be heard through the head phone
Z1. There is also a meter arrangement for accurate measuring of the
signal strength. Transistor Q1 performs additional amplification on the
picked signal in order to drive the meter.
Download Skema :
Electromagnetic Signal Detector
Password : asinan
Download Skema :
Electromagnetic Signal Detector
Password : asinan
IC LF351 Description
The
IC LF351 is a low cost high speed JFET input operational amplifier with
an internally trimmed input offset voltage (BI-FET II™ technology). The
device requires a low supply current and yet maintains a large gain
bandwidth product and a fast slew rate. In addition, well matched high
voltage JFET input devices provide very low input bias and offset
currents. The LF351 is pin compatible with the standard LM741 and uses
the same offset voltage adjustment circuitry. This feature allows
designers to immediately upgrade the overall performance of existing
LM741 designs.
The IC LF351 may be
used in applications such as high speed integrators, fast D/A
converters, sample-and-hold circuits and many other circuits requiring
low input offset voltage, low input bias current, high input impedance,
high slew rate and wide bandwidth.
Features IC LF351
• Internally trimmed offset voltage: 10 mV
• Low input bias current: 50 pA
• Low input noise voltage: 25 nV/
• Low input noise current: 0.01 pA/
• Wide gain bandwidth: 4 MHz
• High slew rate: 13 V/µs
• Low supply current: 1.8 mA
• High input impedance: 1012 Ohm
• Low total harmonic distortion AV=10,: <0.02% RL=10k, VO=20 Vp-p, BW=20 Hz-20 kHz
• Low 1/f noise corner: 50 Hz
• Fast settling time to 0.01%: 2 µs.