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High Voltage Transformers

The data contained herein shows only a PARTIAL LISTING of items available for this product line and it gives only a CONDENSED VERSION of the applicable specifications and characteristics. Request our complete catalog for full information!



High Voltage Transformers are a regular product at PCI, whether as a part of one of our standard HV-M series of D.C. power packs or just a plain transformer, sold as such. While we do not have a "standard" line of transformers, we design and build a wide variety of items for O.E.M. and laboratory use.

Size Limitations, generally speaking, are about 5 KVA for single phase input and 15 KVA for 3 phase input devices. The true limiting factors are the machines on which the transformers are wound. We have the capability to wind wire ranging in size from 5 AWG to 4 AWG. For size comparison, the average human hair is somewhere around 38 to 40 AWG. In some instance, it is necessary to wind the primary of a coil with copper foil and we can wind this material, in widths up to 6 inches, from 1 mil to 10 mil thickness.

Case Style Available: depending upon voltage and current, transformers may be open-frame, encapsulated, in a metal case or phenolic case... oil filled or dry. Most transformers rated 5 KV and higher are in an oil filled container.

Impregnating Fluid is an inhibited, de-gassed and filtered mineral oil, with a flash point greater than 145°C, when measured in accordance with A.S.T.M. test method D 92 or method 110.0.4 of Federal Specification W-L-791. Mineral oil is about as environmentally safe as a choice of dielectric fluid as can be found. It is considered by the U.S. Occupational Safety & Health Administration to be a "Class III-B Combustible."




1. Regulation: the variation in output voltage from no-load to full-load condition, with constant input voltage. Typically, a transformer that is not specifically designated as a "regulated" device may exhibit a 4% regulation factor.

2. Ambient Temperature Range: must be specified in your requirements. Our oil-filled designs are generally rated to operate from -50°C to +85°C without de-rating. Higher temperature rating can be achieved, with oil-filled units, when needed. In open frame designs, lower voltage types, a rating of +125°C is common.

3. Input Voltage and Frequency must be specified. While North American power is generally quite constant at 60Hz, most power utilities have tariff provisions in their service contracts that permit up to a 10% variation in line voltage and "brownout" conditions during peak summer months may result in a drop in frequency. Power lines in other countries deliver a wide variety of voltages and frequencies and may be subject to substantial fluctuations. Military designs that we have provided range from 34 Hz to several KHz, with 400 Hz (for airborn use) being common.

4. Output Voltage and Current should be specified at the maximum current levels that the transformer is expected to deliver. In many instances, a maximum voltage and a "Not To Exceed - KVA" rating is justified.

5. Duty Cycle: is the transformer expected to be operating continuously or, for a laboratory environment, might it be used for only an hour or a minute at a time? Will the transformer be pulsed?

6. Start Grounded? Depending upon your specific application, you may require a transformer that has 2 H.V. output terminals, both insulated from ground; or you may specify 1 H.V. terminal with the start of the secondary winding grounded.

7. Metering Taps: When ultra-precise metering is not required, a simple option is to bring a metering tap from the secondary winding, in some reasonable ratio to the overall output, such as 100:1, 500:1 or 1000:1. This will generally give a reading, accurate to within 2%, of the true output of the transformer.

8. Isolation Transformers. We are often asked to design transformers that will be "floating" at a potential for above ground. This can easily be accomplished by additional insulation, internal to the winding of the transformer.

9. Specify as Follows:

    Input Voltage & Frequency
    Duty Cycle
    Maximum Output Voltage & Current
    Two terminals (floating) or One terminal (start grounded)
    Isolation Voltage Required (if any)
    Environmental Conditions of Use


Examples of transformers designed by Plastic Capacitors, Inc.



1. P/N TR190-403: Input 135V, 60 Hz; output 19KV @ 40 ma; Size 8" x 6" x 8".
2. P/N TRA220-103A: Input 96V, 60Hz; output 22KV @ 445 ma; WATER COOLED; Size 17" x 14" x 12".
3. P/N TUR150AH88: Input 30V, 512 Hz; output 15KV @ 1 ma; Size 6" x 5 " x 5"; Center - Tapped.
4. P/N TRZ5VA12K: Input 240V, 60Hz; output 500V @ 24 ma; Dry type; Size 12" x 16" x 14".
5. P/N TR1000-503B: Input 110/230V, 60Hz; output 100KV @ 50 ma; 2 isolated primaries; phenolic case. Size 12" x 28" x 17". Note 18° scale on top, for size.
6. P/N TR350-107A: 208V, 60 Hz input; 35KV @ 100 ma output; Size 23" x 14" x 14".


For items not yet accessible on our web site, Call (773) 489-2233 or E-mail us to have a compete data sheet fax or mail to you.