Sect. Page I 1
SECTION I
GENERAL DESCRIPTION
1-1 GENERAL of oscillating system in inherent^^ a constant am-
plitude device so that no A. V. C. system, with as-
The Model 202A Low Frequency Function Generator sociated delay in stabilization after frequency changes,
is a compact, convenient, and versatile source of is required
transient-free test voltages between 1200 and .008
cycles per second. It is useful for any general The frequency range from .008 to 1200 cycles per
purpose low frequency testing application and is second is covered in 5 bands. The frequency dial
particularly valuable in the testing of servo systems, is linear.
geophysical equipment, vibration and stability char-
acteristics of mechanical systems, electro-medical The output system is a direct-coupled amplifier
equipment, and for the electrical simulation of system designed for either single ended or balanced
mechanical phenomena. Three types of output wave- output. has It good stability with respect to direct
form are available; sine, square andtriangular. current in the output and very low hum level. Both
Also, a sync output pulse is available for external use. the FUNCTION selectro switch and the AMPLlTUDE
control are so arranged that the characteristics of
The Model 202A Low Frequency Function Generator the amplifier are independent of their position. The
contains a type of relaxation oscillator that is par- internal impedance of the output amplifier is approx-
ticularly advantageous for the generation very of low imately 40 ohms, and the unit is rated to deliver
frequencies. Both a triangular and a squarewave at least 30 volts peak-to-peak to a 4000 ohm load.
voltage function of time are inherent in the oscillating
system. Also, a sinewave function is produced A negative peak sync pulse of 10 volts into a 2500
by synthesis from the triangular wave. ohm load is also provided. It has a duration of less
than 5 microseconds and occurs at the crest of the
Output amplitude and distortion are virtually in- sinewave and at corresponding positions with the
dependent of the frequency of operation. This type other functions. |