Radar System Engineering

SEC. 1011] MISCELLANEOUS COMPONENTS 387
Energy Sources.—The energy source accounts for most of the weight
and much of the complexity of any pulser except those of the a-c resonance
charge type. All conventional types of rectifier circuit can be used in
pulser power supplies. The only design considerations arising from the
nature of the pulser load are those governing ripple and regulation. In
general, the a-c supply frequency will be less than the pulse rate, and
smoothing condensers capable of holding the voltage essentially constant
. -s 7
FIG. 1047 —Low-power airborne pulser.
between pulses must be used. For example, a 60-cycle full-wave rectifier
is brought to full voltage only 120 times per second, so that a pulse rate
of 1200 cps would draw 10 pulses of power between successive recharge
cycles. In figuring ripple it is usually satisfactory to assume a constant
rectifier drain equal to the average current required by the pulser. The
ripple must be kept below that which would cause a change in magnetron
current sufficient to produce either a mode shift or undue frequency
modulation. Apart from thk consideration, amplitude modulation is