PVR200 AC Voltage Regulator

The Knoll PVR200 AC voltage regulator is a member of the Knoll line of power conditioning products. This regulator is designed specifically to protect your sensitive electronics from problems associated with unacceptable voltage swings in AC power. It also maximizes the performance of most audio/video electronics by providing an optimum power source.

Key Features:

General Information:

Knoll Voltage Regulators are intended to protect sensitive electronic equipment from problems caused by AC line voltage irregularities such as brownouts, overvoltages, etc. that can cause audio tonal changes, digital data problems or in extreme cases, permanent damage. They accept input voltages over a wide AC voltage range and convert them to, and stabilize them at, the desired national voltage standard, +/-5V. Voltages approximately +/-10 percent beyond that range may be converted to usable levels, depending on the requirements of the equipment.

The PVR200 features twelve 20A outlets on the back and two 15A outlets on the front. All are functionally interchangeable. The outlets are regulated, spike-suppressed, and filtered against RFI with a three-pole filter, making the unit a full-function power conditioner. There are no controls except an on-off breaker switch.

Limitations: This line voltage regulator is for use with AC voltage only. DC voltages should never be applied to them. It does not change or regulate line frequency. The output frequency will always be the same as the incoming mains line frequency.

Maximum Load: The PVR200 can handle loads totaling up to 20 amperes as long as the input voltage is equal to or above 124 volts. For voltages below that level, its capacity must be derated at approximately .10 amperes per volt. To cope successfully with worst-case brownout conditions, plan for a total load that does not exceed 16.5 amps, or 1980 watts. Please note that this refers to the total power requirements of all equipment plugged into the PVR200 Voltage Regulator, not to each individual item.

Extreme Voltage Protection: The PVR200 includes special circuitry to sense over- and under- voltages and positively shut down the output before possible damage is done. Overvoltages are over 150V. When the input voltage exceeds that limit, the power will cut off. It will come back on automatically when the overvoltage is removed as long as the voltage has not exceeded 300V. The red LED labeled EXTREME VOLTAGE SHUTDOWN indicates the shutdown condition. The power also cuts off for extremely low input voltages below 75V.

To provide protection against dangerously high voltages (those over approximately 300 V) an internal fuse in the PVR200 will blow, but equipment plugged into the Voltage Regulator will not be damaged.

Fuses and Circuit Breakers: There is one circuit breaker and eight internal fuses in the PVR200.

1. A fast-blow 20 amp circuit breaker is used as the on/off switch. This breaker will trip if the unit’s 20 amp capacity is exceeded at any time. If the circuit breaker is tripped, the on/off switch will switch off. To reset it, push the switch back to the on position.

2. A fast-blow 1/4 amp fuse is located inside the PVR200. This fuse will blow if the unit has been connected to a voltage that is above the range of the Extreme Voltage Shutdown circuitry (approx. 300V). To replace it, the unit must be completely disconnected from all power and removed from its rack. The six hex head screws and one Allen head screw holding the top cover must be removed.

NOTE: There are two different types of internal fuses. There are seven 30 amp fuses to protect the voltage switches against faults in the control circuits and the 1/4 amp fuse (mentioned above), to protect the small transformer against line voltages greater than 300V. For continued protection, replace fuses only with the exact same type and rating. The internal fuses are located on the main circuit board.

Input Voltage Monitoring: The row of 10 LED’s at the top left of the front panel make up a meter that indicates INPUT VOLTAGE. Only one LED will light up at a time. There are two red LEDs at the endpoints. When lit, they indicate that the input voltage may be above or below the point where it can be restored to the selected nominal output voltage (though it may still be restored to a usable level) but is not high or low enough to cause an extreme voltage shutdown.

Output Voltage Monitoring: A green LED labeled OUTPUT IN REGULATION indicates proper function (i.e., that the output voltage is within +/-5V of the selected output voltage). Your equipment always will work normally when this light is on, and often will work satisfactorily even when the OUTPUT IN REGULATION LED is off.

Installation: Because of their toroidal transformer design, Knoll Voltage Regulators may be positioned near most other equipment without fear that the other equipment will be disrupted by leakage of a strong 50/60 Hz magnetic field. Ideally the suggested rack location is either at the top or bottom. As with any rack mounting in the rack’s tapped holes (this is not a metric size). In particular, beware of 10-24 screws, which may fit if forced, but which will strip the threads. To avoid marring the front panel finish, use plastic washers under the screw heads.

Design: The PVR200 uses a design based on an eight-tap toroidal autoformer. The toroidal design assures minimal leakage of stray magnetic fields. Because of its high efficiency it is a very compact size for its rating. The Voltage Regulator’s circuitry monitors the incoming line voltage with each cycle, comparing it to an extremely precise voltage reference, accurate to +/-0.15 percent.

If a voltage fluctuation requires that a different tap be selected, the new tap is electronically switched exactly at the zero-crossing, to avoid distorting the AC waveform. If necessary, it can switch taps as often as once each cycle.

Most commercial voltage regulators using multi-tapped transformers switch taps at uncontrolled times, thereby creating voltage spikes and clicks that can leak into the audio. Hysteresis in the switching circuits avoids “chatter” or unnecessary switching back and forth between adjacent taps. And unlike those voltage regulators that employ ferro-resonant transformers, Knoll Voltage Regulators are not sensitive to small errors in line frequency, making them ideal for use with generators.

Definitions:

VOLTAGE REGULATION: The AC line voltage is a number indicating the nominal electrical potential that has been adopted in a region for powering electrical equipment of all kinds. In most of North America it is 117-120 volts AC; in Japan, 100 volts; and in any other countries 220, 230, or 240 volts. The actual voltage can fall below or rise above this nominal level due to brownouts, power cutbacks, use of substandard wiring, and other causes. These deviations can cause poor performance or malfunctions. A regulator is a device which, through use of a transformer, corrects the voltage deviation by stepping it up or down so that it is as close as possible to the nominal level.

SPIKE: A pulse of energy on the power line. Spikes can have voltages as high as 6000 volts. Though they are usually of short duration, the energy they contain can be considerable, enough to damage sensitive solid-state components in audio and computer equipment. Spikes can also foul switch contacts and degrade wiring insulation. They are an unavoidable component of electric power. Spikes are caused unpredictably by electric motors switching on or off (on the premises or outside), utility company maintenance operations, nearby lighting strikes, and other factors. Spikes (also called surges or transients) are absorbed by special components called MOV’s in the PVR200 to provide safe voltage levels to protect your equipment.

RFI/EMI INTERFERENCE: Noise from RFI (Radio Frequency Interface) or EMI (Electro Magnetic Interference) involves lower voltages and less energy than is found in spikes, but it is continuous rather than transient in nature. It is not likely to cause physical damage, but it can certainly be annoying, producing static in audio circuits, “snow” on video screens, or garbled data in computers. Noise can be introduced into AC lines nearby radio transmitters, certain kinds of lighting, electric motors, and others. Because noise occurs at higher frequencies than the 50 or 60Hz AC line, it can effectively reduced through use of low-pass filtering.

Available Output Current vs. Input Voltage

Output Voltage vs. Input Voltage

Specifications:

Note: Specifications subject to change without notice.