Vicor Javelin II - Manual (Page 5)

Javelin I & II Power Supply Operator’s Manual
Voltage conversion is achieved by Vicor’s family of Zero-Current-Switching (ZCS) DC-DC converters. These
are forward converters in which the main switching element switches at zero current. This patented topology
has a number of unique attributes: low switching losses, high frequency operation (resulting in reduced size for
magnetics and capacitors), excellent line and load regulation, wide output adjustment range, low EMI/RFI
emission, and high efficiency.
At initial power-up, the Javelin output is disabled to limit the inrush current and to allow the DC bus potential
to settle out to the correct operating level. A low-power flyback converter operating with PWM current-mode
control converts the high voltage DC bus into regulated low voltage to power the internal housekeeping circuits
and DC cooling fans.
The internal housekeeping Vcc comes up within 1 second after the application of input power. Once the high
voltage bus is within operating limits, the AC Power OK signal changes its output to a TTL “1,” indicating the
input power is OK, and allows the power output to come up 15-30 ms later. An auxiliary Vcc output of 5 VDC
capable of sourcing up to 300mA is provided for peripheral use.
An output Inhibit/Enable function is provided by using an optocoupler to control Vicor’s DC-DC converters. If
the Inhibit control pin is pulled low and the Enable pin is high or open, the optocoupler will turn on and disable
the output. The delay for an output to come up when measured from release of the Enable pin is 5-10 ms.
Power
Output
Line Filter Rectifier
Soft Start
Circuit
Boost Converter
Output
PFC Control
Customer
Interface
I/E Control
Fan
Housekeeping
Power
Input
Current
Sample
Waveform Sample
Inhibit/Enable Control
Inhibit/Enable
Figure 1. Javelin Architecture
Interface Connections
Input Power Terminal (J1)
Input AC (and DC) Power is applied to connector J1 using a 3W3 power
connector. J1-A1 is Line (L1), J1-A2 is Line 2/Neutral (L2/N), and J1-A3 is
Earth Ground (G) for safety.
A fault-clearing device, such as a fuse or circuit breaker, with a maximum
15A rating at the power supply input is required for safety agency compli-
ance. It should be sized to handle the start-up inrush current of 30A at 115
VAC and 60A at 230 VAC.
Rev. 05/11/2012 Mission Power Solutions (760) 631-6846 [email protected] Pg. 5
J1 Pin Out
A1
Line 1
A2 Line 2/Neutral
A3 Ground
A1 A2 A3