Download 1. Introduction - Peekel Instruments

Peekel Instruments
User manual CA2CF Version 1.0
1.3 General design principles
The following drawings only show the basic principles of the electronics, as it is outside the
scope of this user’s manual to go in full detail.
The Amplifiers
gnd
-IN
+IN
+EX
-EX
1/4
+SE
-SE
125 uV/V .. 1V/V
IN
SE
+
ZERO
9p M
Dsub
Bandpass
Gaincontrol
Input
Control
C-BAL
Phase
shifter
Lowpass
R-BAL
Analog
OUT
350Ω
1/4
120Ω
Bridge completion
240Ω
+ EX
Demodulator
(Detector)
240Ω
1/2
Phase
5 KHz exc.ref.
- EX
Page 4 of 21
The drawing shows the
evident advantage: the two
transformers, fully isolating
the measuring input from the
rest of the system.