Pulley-Driven Generator or Alternator (cont)

(6) T u r n the tachometer indicator cali-

r p m . If mounted on the high speed

brating potentiometer (58) to the

head, select a point on the tachometer

" M A X " position and the tachometer

i n d i c a t o r meter (reading on upper

i n d i c a t o r direct-drive-calibrating po-

scale) in the vicinity of 6,000 rpm.

t e n t i o m e t e r switch (19) to the "CAL

(5) D e t e r m i n e t h e s p e e d ( r p m ) o n t h e

POT" position.

d r i v e n generator or alternator pulley

using the following formula:

(7) If the speed (rpm) of the driven pul-

ley calculated in (5) above is greater

than the preset speed (rpm) of the

d r i v e r pulley in (4) above, turn the

Where

Speed (rpm) of driven

t a c h o m e t e r indicator high-low switch

g e n e r a t o r or alternator

(18) to the "HI" position. If the speed

(9, fig. 20) pulley

(rpm) of the driven pulley is less than

(X) = Preset speed (rpm) of

t h e preset speed (rpm) of the driver

p u l l e y (driver) on test

pulley, turn the switch (18) to the

stand (8, fig. 20)

"LO" position.

D = Diameter of driven pulley

(8) T u r n the tachometer indicator cali-

( g e n e r a t o r or alterna-

b r a t i n g potentiometer (58) until the

tor) (9, fig. 20).

s p e e d (rpm) calculated in (5) above

4 = Diameter of driven pulley

is indicated on the tachometer indica-

of the generator or al-

t o r meter (3).

ternator (9, fig. 20).