EPOCH-II with EPOCH-10 control unit
EPOCH-II
High-Current Output Unit
SPECIFICATIONS
Input
Input Voltage (specify one)
115 V ±10%, 50/60 Hz, 30 A (at full rated output) 
OR
230 V ±10%, 50/60 Hz, 20 A
Output
Output Current
To provide a variety of test circuit impedances, six output taps 
with two ranges are provided. 
High Range
2.00 to 10.00 A at 100 V max
3.00 to 15.00 A at 66.6 V max
8.00 to 40.00 A at 25 V max
10.00 to 50.00 A at 20 V max
20.00 to 100.0 A at 10 V max
34.00 to 170.0 A at 5.9 V max 
Output Power: 1000 VA
Low Range
2.00 to 10.00 A at 50 V max
3.00 to 1 5.00 A at 33.3 V max
8.00 to 40.00 A at 12.5 V max
10.00 to 50.00 A at 10 V max
20.00 to 100.0 A at 5 V max
34.00 to 170.0 A at 2.95 V max 
Output Power: 500 VA
Accuracy
Typical: ±0.5% of setting 
Maximum: ±1.0% of setting
Alarm will indicate when amplitude, phase angle, or waveform is 
in error. 
Resolution
Four ranges: 0.01 A 
Two ranges: 0.l A
Duty Cycle
Five minutes at full rated VA output. Fifteen minutes recovery 
time. 
Overrange Capability 
The EPOCH-II has an overrange capability of +10% for each tap 
with a maximum output current of 187 A on the 170 A tap.
Distortion 
Less than 1% typical, 3% max. 
Output of EPOCH-10/EPOCH-II Combination 
Frequency
■ Synchronized to input power source 
■ 60 Hz crystal-controlled 
■ 50 Hz crystal-controlled
Accuracy
■ Synchronized, tracks input frequency
■ ±0.006 Hz for 60-Hz crystal control (±001%)
■ ±0.005 Hz for 50-Hz crystal control (±0.01%)
Output of PULSAR and Interface Module Connected to EPOCH-II 
The High-Current Interface Module provides a variable frequency 
signal to the Epoch-II High-Current Output Unit. 
Output frequency is continuously displayed for each channel with 
large, high-intensity LEDs with the following ranges:
5.000 to 99.999 Hz
100.01 to 999.99 Hz 
Frequency Accuracy: ±10 ppm at 23° C, ±2° C)
Current Phase Angle Control
Angle is adjusted on the EPOCH-10 control unit by 4-digit, 
pushbutton control with large LED display of setting.
Range: 0.0 to 359.9° 
Resolution: 0.1° 
Accuracy: less than ±0.3° typical, ±1.0° max 
Control Section
The control unit for the EPOCH-II high-current section is PULSAR 
(with the High-Current Interface Module), an EPOCH-I or EPOCH-
10. Thus, the excellent operating and control features of PULSAR 
and the EPOCH-10 are used to control the EPOCH-II. 
Note: When the EPOCH-II is in use, the current output of the 
EPOCH-10 control unit is inoperative. All EPOCH-10s can control 
an EPOCH-II high-current section. When the high-current section 
of the EPOCH-II is not needed, the EPOCH-10 can be used 
independently or slaved together with other EPOCH units.
Protection
The input line circuit is breaker-protected. The dc power supply is 
overcurrent-protected. In addition, overvoltage protection is 
provided on the input line circuit. 
The power amplifiers are forced-air cooled and are protected by 
thermal-overload sensors. 
Audio and visual alarms on the PULSAR and EPOCH-10 control 
units indicate whenever the current or potential outputs are 
overloaded.
Temperature
Operating 
32 to 122° F (0 to 50° C) 
Reduced duty cycle above 113° F (45° C)
Storage 
–13 to +158° F (–25° to +70° C)
Dimensions
7.6 H x 19.75 W x 21.6 D in. 
(193 H x 502 W x 549 D mm)
Weight
115 lb (52.3 kg)