JQE SPECIAL OPR 092611
4-5/(4-6 Blank)
4.4.4
MINIMUM OUTPUT CURRENT CHECK
1.
Adjust I
lim
control to full counterclockwise position.
2.
Verify that output current is 0.1A ±10mA.
4.5
OVERVOLTAGE PROTECTION (OVP) TEST AND ADJUSTMENT
1.
Use the VOLTAGE control at the front panel to set the output voltage to the desired voltage
as measured by either the front panel voltmeter or by an external DVM.
2.
Turn OVP DELAY ADJ potentiometer (accessible through top cover) to approximately the
middle position (five turns from one end).
3.
Slowly, turn the OVP ADJ potentiometer counterclockwise until the power supply circuit
breaker trips OFF. Then turn OVP ADJ potentiometer clockwise between 1/4 and 1/2 turn.
4.
Turn on the JQE special power supply. The circuit breaker should not trip and the output
voltage, measured by either the front panel voltmeter or by the external DVM, should the
same as step 1 above.
NOTE: The OVP circuit causes the circuit breaker to trip and initiates the Output Crowbar, a
solid state switch (thyristor) across the output. Adjust OVP DELAY ADJ potentiometer
so that the circuit breaker does not trip while the unit is operating with your particular
load and application. To avoid tripping the circuit breaker unnecessarily, for example
upon encountering load transients, a compromise must be made between the follow-
ing:
• Rapid OVP action (minimum tolerance for output overvoltage):
OVP DELAY ADJ set to full counterclockwise position and
• Maximum delay of OVP action (where some overvoltage is acceptable):
OVP DELAY ADJ set to full clockwise position.
5.
Repeat steps 1 through 4 above for any desired operational output voltage above 5%
E
Onom
.
