Datasheet

Figure 23: P.C. board and componentslayout of the circuits of Figg. 20, 21, 22.
APPLICATION SUGGESTION (Fig. 20,21,22) - (For a 2000 r.p.m. 3 pole DC motor with R
M
=16Ω)
Components
Recommended
value
Purpose If larger If smaller
Allowed range
Min. Max.
R
S1
1Ω Current sensing
tacho loop.
Tacho loop do
not regulate
0
R
S2
1.5Ω Current sensing
V/I loop.
Instability may
occur.
Motor regulator;
undercompens.
0R
MOT
/9
R
L
;C
L
22KΩ - 68nF Spike filtering. Slow V/I
regulator
response.
High output
ripple.
C
D
68nF Pulse transf. 33nF 100nF
R
T
;C
T
15KΩ - 47nF Current source
programming to
obtain a 50%
duty cycle
67KΩ 30KW
R
P1
;R
P2
47KΩ trim. Set of speed. Low speed. High speed 0
C
F
Polyester 100nF Optimization of
integrator ripple
and loop
response time.
Lower ripple,
slower tacho
regulator
response.
Higher ripple,
faster response.
10nF 470nF
R
A
;C
A
220KΩ - 220nF Fast response
with no
overshoot.
Depending on electrmechanical
system.
10nF 470nF
A
TDA7272A
13/16