LEESON Chassis Mount SCR Control - Manual (Page 49)

43 SPEEDMASTER™ OPERATION MANUAL
Multiple fixed speeds
Replace the speed adjust potentiometer with series resistors
with a total series resistance of 10K ohms (Figure 21). Add a
single pole, multi-position switch with the correct number of
positions for the desired number of fixed speeds.
S3
S2
S1
R1
R2
R4
TOTAL SERIES
RESISTANCE
10K OHMS R3
Figure 21. Multiple Fixed Speeds
Application Notes