RMIC
6
5
21K
7
2
10
9
BASE CURRENT
COMPENSATION
8
33K
3
4
RE
1
Fig. 2 Functional Schematic
V
= 1.3 VDC
ED1913
B
6
RMIC
5
1.0
R
LAC
21K
- A
- B
- C
7
8
4
C
0.22
S
R
S
= 3.9K
RE
1
3
2
10
9
100K
100K
120
0.1
5.6K
R
VC
R
GT
All resistors in ohms, all capacitors in Farads unless otherwise stated.
R
R
R
GT
VC
LAC//21K
R
E/120
Gain of stage A = 20 Log
Gain of stage B = 20 Log
Gain of stage C = 20 Log
10
10
10
R
5.6K
S
Fig. 3 Typical Hearing Aid Circuit
3
510 - 70 - 3