AMETEK SLH Series RevB - Manual (Page 32)

Operation SLH-Series AC High Power Electronic Load
3-6 M540073-01 Rev C
VA:
Press the LIMIT key until the LIMIT LED is on and the “VA” LED (5) is lit. The upper DM
displays the upper VA limit; the lower DM displays the lower VA limit. Use the coarse

to set the upper limit and the fine ↑↓ keys to set the lower limit.
Vsense Input: The “SENSE” key toggles external Vsense on (LED lit) and off (LED not lit).
Frequency Setting:
The range for setting the frequency of SLH-Series AC electronic Load AC/DC module is
from DC-70Hz. Specifications apply 40-70Hz.
Press the FREQ key (15) until its LED lights and “FrEq” appears on the upper DM.
Use the coarse/fine
/ ↑↓ keys to set the frequency to the desired value, to DC or to Auto.
• If the frequency setting is less than 0.1 Hz, the frequency setting value will set
automatically to DC.
• In Auto, the load automatically synchronizes to the zero crossing of the voltage input
at the terminals.
• After setting the frequency, set the SYNC trigger to OFF to make the frequency valid.
Current Synchronization (Figure 3-3)
External SYNC Signal (SYNC ON)
The user can input a SYNC signal to the Analog Programming Input BNC connector on
the back plate.
Based on this external SYNC signal, the SLH-Series AC Electronic Load, the phase of
load current will synchronize to the zero crossing of the external signal.
The external SYNC signal must have be a 50% duty cycle.
Press the “FREQ” key until “Sync” appears on the upper DM.
Press any
 ↑↓ key to toggle the external sync on and off.
Internal SYNC signal (SYNC OFF)
The internal SYNC signal source of SLH-Series AC electronic load is taken from the
voltage signal at the terminal inputs.
The load current signal will synchronize to the voltage zero crossing of the input
terminals.
Zero Crossing SYNC Input
SYNC "OFF"
+5V
330Ω
SYNC
EXT+
EXT-
SYNC "ON"
Figure 3-3 Illustration of Sync