![background image](http://html1.mh-extra.com/html/curtis/1297/1297_manual_2699565023.webp)
Curtis PMC 1297 Manual
15
Preliminary on Verso page is set with right edge at 7 and 7/8,
and the top (as on the Recto page) at 1/4.
Current Source Used As a Speed Control Device
A current source can be used as a throttle input as shown in Figure 7. A resistor,
R
throttle
, must be used to convert the current source value to a voltage. The resistor
should be sized to provide a 0–5V signal variation over the full current range.
It is the responsibility of the OEM to provide appropriate throttle fault
detection for current sources used as throttles.
Fig. 8
Wiring for 3-wire
potentiometer throttle
(“Type 2”).
3-Wire Pot Throttle (1k
Ω
–10k
Ω
)
The 3-wire potentiometer is used in its voltage divider mode, with the voltage
source and return being provided by the 1297 controller. Pot High provides a
current limited 5V source to the pot, and Pot Low (Pin 22) provides the return
path. Wiring is shown in Figure 8 and also in the standard wiring diagrams,
Figures 3 and 4. Potentiometers with total resistance values between 1k
Ω
and
10k
Ω
can be used.
Fig. 7
Wiring for current
source throttle (“Type 2”).
14
13
15
16
17
18
19
20
21
22
23
24
12
11
10
9
8
7
6
5
4
3
2
1
1k
Ω
–
10k
Ω
J1
1k
Ω
–
10k
Ω
Wiper input (Pin 4)
Pot Low input (Pin 22)
Pot High output (Pin 10)
Traction
Throttle
Hydraulic
Throttle
Hyd. Wiper input (Pin 21)
FASTER
FASTER
14
13
15
16
17
18
19
20
21
22
23
24
12
11
10
9
8
7
6
5
4
3
2
1
R
throttle
I
source
B-
B-
R
throttle
I
source
B-
B-
J1
0–5V input (Pin 4)
Traction
Throttle
Hydraulic
Throttle
Hyd. 0–5V input (Pin 21)
2 — INSTALLATION & WIRING: Throttles
When a 3-wire pot is used and the Pot Low Check parameter (see Section 3
A
,
page 40) is set to On, the controller provides full fault protection in accordance
with EEC requirements.
NOTE
: Pot Low Check applies only to traction throttles.