Section 3. Operation
TTL Shutdown
24 Operating Manual for APG for XT/HPD Series Power Supply
TTL ShutdownTTL Shutdown allows the output of the power supply to be disabled by a logic level
signal. This input is optically isolated from the power supply output and will
withstand a highpot test potential of 600Vac minimum. When TTL shutdown is
activated, the front panel LED comes on.
•Connect the signal source between J5 connector pins 15 (TTL
shutdown/positive) and 2 (TTL shutdown return/negative).
•Set rear panel switch S1-1 (TTL shutdown) to ON (closed) to obtain positive
logic (high signal enables output). The factory-set default is switch OPEN for
negative logic (high signal disables power supply output).
Notes:Minimum activation signal required: 2V at 500µA
Maximum activation signal allowed : 25Vdc
Switch SW1-1 Setting TTL Signal Level Output Condition
OPEN (Negative logic) HIGH
LOW
OFF
ON
CLOSED (Positive logic) HIGH
LOW
ON
OFF