S14-4 Switching Amplifier

The S14-4, is a 7" high rack mounting box with a pre-amp, four OUT-14 boards, output transformers, and all necessary power supplies. It is rated at 12 kVA, 10 msec on, 1% duty. The standard cabinet has room for 10 kHz transformers.

The use of an energy storage system keeps the weight to a minimum and prevents large surge currents from being drawn from the power line. The S14-4 is a logical choice when a compact, high power, low duty cycle amplifier is needed. Several of these units are being used in an experimental mine-hunting sonar system.

The OUT-14 is a full bridge FET switching PWB with TTL input. It is rated at 3 kVA, 10 msec on time with a 1% duty cycle. There is room on the board for an output transformer rated for 80 kHz minimum frequency. This PWB is 6.3 x 12 x 1.5 inches.

Specifications for Standard S14-4 Amplifier

Type of amplifier	Four (4) bridge FET output, switching
Modulation (specify which)	Square, Stair-Step, or PWM
Output	12 kVA for 10 msec
	1% max duty cycle
Load power factor range	0 - 100% capacitive or inductive
Output Voltage Taps (V RMS)	Contact factory
Frequency range (-3 dB)	PWM 50 kHz max
	Stair-Step 10-200 kHz or 80-400 kHz
RMS noise (below max output)	-60 dB gated on (PWM only) -120 dB gated off
Distortion (THD)	PWM: 1% max, 0.2% typical
	SS: approximately 10% at full output voltage
Input impedance	5 k ohm
Input voltage for full output	1 V RMS for full output
Gate signal	TTL levels (5 V)
Current monitor	100 mV/A
Voltage monitor	10 mV/V
Protection	No combination of passive loads, input signals or
	switch settings will cause amplifier failure.
Fault lights	Temp limit, modulation limit, current limit, blown fuse
Ambient temperature	0 - 40 degrees C
Primary power	120/240 V 50/60 Hz 1 ph
Size (inches)	7 x 19 x 20 (plus front handles) Rack Mounting
Weight (pounds)	50
Amplifier Photograph	S14-4
Output Amplifier Photograph	OUT-14 Series Output PCB

SS-P6-4

This model is similar to the S14-4 but has a dual frequency (80/350 kHz) switch selectable oscillator circuit on the pre-amplifier. It also has output tuning to minimize distortion.

The output transformer system does not use a front panel switch, but does have internally selectable taps to best match transducers at the two frequencies.