CUSTOM ENGINEERED POWER SUPPLIES

Virtual Technologies, Ltd. brings to power supply design and production the same skills and advantages that have made us number one in alternative energy electronics.  Our vertical integration, highly efficient facilities, and steadfast obligation to quality and service excellence have enabled us to provide high-value custom engineered power supplies to many satisfied customers.

Virtual Technologies engineers, designs, and manufactures both standard and customized AC-AC, AC-DC, DC-DC, and DC-AC power supplies.  Our designs fulfill power requirements ranging from 5 watts to 750 kilowatts. 

Virtual Technologies' greatest advantage is our pledge to serving our customers.  Recognizing your need to lower costs and get products to market faster, our team delivers your solution on time and on budget.

HIGH VOLTAGE SUPPLIES

Virtual Technologies is a leader in the design and manufacture of precision, regulated high voltage DC power supplies from 500V to 120kV and up to 750kW in power. Virtual Technologies high voltage supplies are available as custom units, specifically designed to meet your requirements.  Virtual Technologies can provide science and industry with innovative high voltage solutions for your applications.

DESIGNS to MEET YOUR NEEDS

Virtual Technologies can meet your most challenging requirements.  Our custom design and manufacturing process starts with our in-house engineering staff, all of which have extensive experience in power supply engineering, high voltage applications, and project management.  Our design team is equipped with the most sophisticated computer design and analysis tools available.  We will work according to your specification, or work jointly with you to develop a specification for your product. Virtual Technologies design team works integrally with our customers to prepare custom product for prototyping and manufacturing.

Virtual Technologies' modern facilities host production projects from large OEM runs to small lots for special applications.  Our devoted areas for R&D and prototyping permit Virtual Technologies to offer unparalleled flexibility in bringing customer requirements to realization.

CUSTOMER SUPPORT

Once production is commenced, Virtual Technologies provides world-class customer support, from application engineering and technical support, to flexible delivery options that reflect the reality of your business and strategic requirements.  Our account managers and representatives round out the support team that gives you 100%.  Look to Virtual Technologies, the experts in high power and high voltage, for your custom power supply needs.

QUALITY

Virtual Technologies' in-house quality assurance guarantees that each custom power supply meets and exceeds your expectations for performance and reliability.  From the initial conceptualization, to design, prototyping and  production and delivery, Virtual Technologies optimizes quality while minimizing cost.  Every custom power supply goes through a rigorous battery of testing that guarantees flawless field operation.

SPECIAL CERTIFICATIONS

Should your application require special certifications (UL, ETL, CE, CSA, etc.,) Virtual Technologies can handle the process for you, or we can support your self-certification effort.  You can rely on Virtual Technologies for quality assurance through all phases of the custom design process.

POWER REGULATION

Some applications may require power regulation.  Virtual Technologies can design and manufacture power supplies that measure both output voltage and output current and electronically calculate the output power.  This product is then used to maintain the output filament power at the set value.

RIPPLE

Ripple is the unwanted AC that exists on the DC power supply output.  It typically has an adverse affect on operation and should be kept to a minimum.

The two most common ways of specifying ripple are peak-to-peak (P-P) and root-mean-square (RMS).  Each is generally expressed as a percentage of the average DC output.  Peak-to-peak, the more stringent method of characterizing a waveform, is measured by looking directly at the output and measuring the difference between the highest and lowest points.  It is always a greater number than the RMS value.

If the ripple waveform is a pure sinusoid, the peak-to-peak value is 2.8 times greater than the RMS value. A purely sinusoidal ripple waveform is very rarely the case.  If the waveform contains periodic spikes, then the measured peak-to-peak value can be 10, 100, or even more, times greater than the RMS value.  Without a detailed characterization of the ripple waveform there is no way of concluding what the peak-to-peak ripple is from an RMS value.

VOLTAGE SPIKES

In many applications voltage spikes will adversely affect the performance of the device being powered or introduce errors into associated instrumentation. In these situations knowledge of the maximum peak-to-peak high voltage variations is critical. Virtual Technologies specifies output ripple in peak-to-peak values, rather than RMS, to more accurately express the true ripple component.

SPECIAL FEATURES

REMOTE PROGRAMMING

There are several techniques to remotely control Virtual Technologies power supplies. All techniques use low voltage programming signals or components and all circuits are normally referenced to ground.

The simplest approach to implement is remote potentiometer programming. This is essentially a remotely located front panel control.  In this mode, the potentiometer is connected between the power supply's reference output and common.  The wiper of the potentiometer is then connected to the remote input. The applied programming voltage will be proportional to the potentiometer rotation.  Resolution of the output setting is determined by the resolution of the potentiometer.

CONTINUOUS ADJUSTMENT

If, instead of continuous adjustment, a number of specific voltage values are required, then the potentiometer can be replaced by a series string of resistors and a multi-position switch.  Resistors in series with a potentiometer can be used to achieve greater resolution over a limited voltage range than obtainable using only a potentiometer.  One can use a precision low temperature coefficient resistors with a total resistance of approximately 5K ohm. 

REMOTE VOLTAGE PROGRAMMING

Remote voltage programming is accomplished by applying a signal voltage at the control input.  Resolution of remote analog voltage programming is essentially infinite.  Power supply input impedance is typically high, 1 mega ohm or greater. For greatest accuracy and lowest possible noise, the circuit providing the programming signal should have a low output impedance.  A programming source output impedance of 100 ohms, for example, results in an error of less than 0.01%. The error caused by the programming source impedance is easily predicted. 

DIGITAL PROGRAMMING CARD

Virtual Technologies power supplies can be ordered with an optional digital programming card installed. This option includes a variety of user selectable programming modes.  Connection can be made via an 8-bit or 16-bit data bus. Configured for operation with an 8-bit data bus, the unit retains 16-bit resolution, accepting a 16-bit word in two 8-bit bytes.

REMOTE MONITORING

Custom designed Virtual Technologies power supplies can provide monitor signal outputs which are proportional to the output voltage and output current. Similar to the programming inputs, all monitor signals are low voltage and referenced to ground. The resolution of the remote analog monitor signals is infinite.  These monitor signal outputs can be fed to wireless sources, data loggers, remote displays, meters, and similar equipment.

The voltage monitor circuit relies on a precision high voltage resistive divider to determine the exact output voltage.  It is this signal, after buffering, that appears at the voltage monitor output. The current monitor circuit is also ground referenced and precisely measures output current without injecting a voltage drop or any other error at the power supply output. This circuit does not interfere with the power supply output return, which remains at ground.

Remote digital monitoring can be implemented using an IEEE-488 interface, or by using an analog-to-digital converter (ADC). Call Virtual Technologies Application Engineering for assistance at (509) 244-3252.

HIGH VOLTAGE CONNECTORS

The output high voltage connectors used on Virtual Technologies custom power supplies are selected to achieve long-term, unfailing, noise-free operation.  Our custom power supplies can be provided with mating connectors and cables.  If remote assembly of the mating connector and cable is required, assembly and potting directions can be provided; they must be rigorously followed to prevent corona, arcs, noise spikes and "creepage" currents.

Virtual Technologies can design and provide high voltage cable assemblies, and can provide a wide range of standard and custom cables to meet your specific  requirements. 

ENCAPSULATION

Encapsulation of the high voltage components is offered in all Virtual Technologies designed power supplies.  This provides improved performance and reliability.  Encapsulation provides a clean, stable, well-defined long life environment for all critical high voltage components.  It prevents the initiation of corona and other destructive phenomena which can occur in air at high voltage potentials.  Encapsulation materials used are selected for their mechanical and thermal properties as well as their insulating characteristics.

CIRCUIT PROTECTION

All Virtual Technologies power supplies provide protection against overloads, short circuits, open circuits and arcs.  High voltage power supplies must be capable of operation under potentially erratic load conditions.  If the supply were not adequately protected, these conditions could easily cause a catastrophic failure of the load or of the power supply.  Protection is required for the reliability of the associated equipment as well as the power supply itself.

Voltage regulated power supplies must be protected against short circuits by providing safe, well defined current limiting.  Open circuit protection may initially seem to be a trivial requirement.  However, for current regulated supplies, an open circuit is analogous to a short circuit on a voltage regulated supply.  Current regulated power supplies can be protected against open circuits by providing safe, well defined voltage limiting.

REMOTE ENABLE - INTERLOCK

Many applications require a high voltage interlock or an external means of shutting down the high voltage supply.  Virtual Technologies can design and produce supplies having an enable or trip input for this purpose.  Depending on need, a TTL compatible signal, open collector transistor, switch or relay can be employed to remotely gate high voltage operation.  For remotely programmed supplies, the output can also be shut off by setting to program voltage to zero.  Another way of accomplishing this function is with an interlock switch to shut down the primary input power.