Page 6 of 22
Vox Power Limited | Unit 2, Red Cow Interchange Estate, Ballymount, Dublin 22, D22 Y8H2, Ireland | T +353 1 4591161 |
DOC-MN-008-03, VCCS300 User Manual
Startup & Shut Down Timing
The VCCS300 operates from a universal input voltage range and starts automatically upon application of adequate AC mains voltage (>50V
RMS
). After a short delay the
output voltage starts and delivers power to the application loads.
The diagram below shows the normal start up/shut down sequence and gives typical timings.
Typical timing values at 120Vac 300W 25
°
C: t
1
ϕ
≈
600 ms, t
2
ϕ
≥16ms (minimum)
When the AC mains voltage is removed, the internal hold-up capacitors will supply power to the load for typically 16ms (t
2
) at maximum power.
Hold-up
For short line distubances (<16ms), the unit can deliver full output power without disturbances on the output voltage.
No Load Power Consumption
The VCCS300 series has an extremely low no-load power consumption of <1W. To achieve this the unit enters burst mode when the output power is below 6W. When
in burst mode the ripple frequency will reduce significantly. The unit returns to normal operation when the output load goes above 12W.
Input Over Current Protection (OCP)
The input circuitry is protected from excessive input current by means of an over current protection circuit which limits the input current to approximately 5Arms
.
If
the OCP threshold is exceeded the unit may shut down and attempt to automatically restart.
Input Under Voltage Protection (UVP)
The input circuitry will not operate until the applied mains voltage exceeds 50V
RMS
. Once the unit is active it can operate down to approximately 10V
RMS
under no load
conditions. When operating below the minimum specified mains voltage (85V
RMS
) the input circuitry is protected by the input over current protection (OCP).
Over Temperature Protection (OTP)
The unit is protected from excessive temperatures by means of various internal temperature sensors. If temperature thresholds are exceeded the unit may turn off.
The unit will automatically recover once it has cooled sufficiently.
