Vicor Javelin II - Manual (Page 7)

Javelin I & II Power Supply Operator’s Manual
Auxiliary Vcc +5V/0.3A (J2-5)
The Vcc on J2-5 is an auxiliary 5V regulated power source. It is +5VDC 5% with respect to Signal Ground
(J2-4 and J2-2) and can supply 300mA maximum. It is short-circuit proof, but if shorted, all outputs will be
shut down through the Inhibit/Enable circuitry.
Figure 3. Auxiliary Vcc Circuit
Remote Sense Connections
The Javelin is shipped from the factory with Auto-Sense installed. If Remote Sense is desired, sense leads
must be connected from J3-1 (+Remote Sense) and J3-6 (−Remote Sense) to the load point where regulation is
required.
When Auto-Sense is used, the power supply will regulate the output at the output terminals. The voltage ap-
pearing at the load may drop slightly due to voltage drop in the power cables. If it is necessary to compensate
for voltage drop along the output power cables, the output can be trimmed up or configured for Remote Sense.
Use stranded, twisted pair 20-24 AWG wire for the Remote Sense lines. Remote Sense can compensate for a
voltage drop of up to 0.5V, or 0.25V on each leg.
Rev. 05/11/2012 Mission Power Solutions (760) 631-6846 [email protected] Pg. 7
DC OK and DC OK′ are logic signals provided to indicate with either TTL logic “1” or “0” that the correct
output voltage is available. DC OK (J3-8) is a logic “1” when output voltage is within specification and a logic
“0” when output is out of tolerance. A logic “0” is capable of sinking 16 mA in either circuit. The inverse
signal, DC OK′, is available at J3-2. The circuit is operated with a +5Vcc provided by either the customer or
taken from connector J2-5 (+5V Vcc) and J2-2 (+5V Return).
MOC217
J3-3 +5V Vcc
J3-2 DC OK’
J3-8 DC OK
J3-7 +5V Return
2N7002 2N7002
49.9K
4.99K 4.99K
DC OK
Figure 4. DC OK Circuit
78M05
+5V/300mA J2-5 Auxiliary Vcc
J2-4 Signal Ground
0.1uF
J2-2 Signal Ground
DC OK/DC OK′ (J3-8 and J3-2)