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Transformers and InductorsHill Technical Sales offers a large range of standard and custom designs from the best manufacturers in the world. Most custom designs can be processed in 1 to 2 weeks. Pricing on standard products can normally be quoted the following business day. |
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Available Types
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Auto-transformers are used strictly in a step-up or step-down application. They are very similar to isolation transformers with one important exception. In an auto-transformer the primary and secondary windings are electrically common to each other. The advantage of using an auto-transformer over an isolation transformer is its smaller size and lower cost. The major disadvantage is no isolation between the primary and secondary which allows noise on the power line to be directly coupled to the load. One last disadvantage is that auto-transformers provide no regulation. It is also important to note that the greater the change in voltage the less cost effective a auto-transformer is. Some common applications for auto transformers are motors, heaters, and other non sensitive loads.
Used primarily in a step-down environment to power low voltage accessories.
Sizes: 5VA minimum rating.
Special type of ferroresonant transformer that has an additional winding
which a variable DC control voltage is applied. When this winding is used in conjunction with a feed back circuit the transformer provides much tighter secondary regulation. This can also be used to add flexibility to the output voltage based on the designers requirements, for example regulation adjustment for different frequencies. .
This ballast offers a linear variation of output power from 40 to 100% as
opposed to capacitor switching which changes lamp power as a step
function. This is accomplished by varying the conduction time on an
inductor which negates capacitance in the circuit allowing enhanced
control of lamp current. Lamp current is sensed in a closed feedback
loop circuit which can instantaneously respond to changes making the
necessary adjustments. A PLC interface is available to communicate with
the ballast in order to vary lamp output. In order to protect all of
the control circuitry from power problems typically found on the primary
the control circuits are all located on the secondary of the ballast.
Current transformers are designed for connection in series with the line in
the same manner as that for ordinary ammeters- the secondary current bears
a known relation with the primary current; consequently, any change in the
primary current will be reflected in the meters or other devices connected
in series with the secondary terminals of the transformer. Sizes vary from
ID of 0.60" to 8" and up to 10" x 24" for bus bar designs.
We can supply coils of most any size to be used with or in various OEM
assemblies.
AUTO TRANSFORMER
CONTROL TRANSFORMER
CONROLLED FERRORESONANT (also see ferro's)
CONTROLLED FERRORESONANT BALLAST
Features:
CURRENT TRANSFORMERS
Current Transformer Types
CUSTOM COILS
| Edge winding is a technique in which a rectangular magnet wire is wound on its narrow edge. This allows a much greater surface area to dissipate more heat than conventional winding techniques. Edge winding is used mainly in isolation transformers and inductors that have high load currents at lower voltages. |  |
Ferrite materials are used for high frequency magnetic applications which
include transformers and inductors Ferrite materials are used because of
their efficiency and responsiveness at these frequencies, enabling the
power supply designer to reduce the size of magnetic designs dramatically.
Cores come in over a dozen shapes and a multitude of sizes. The components
in a power supply and the ferrite core transformer are closely intermingled
electrically by design, and each has a great effect in the performance of
the other. In this case it is important to fill out the general
specification sheet and then for our engineers to work closely with you on
these designs.
Used primarily in uninterruptible power supplies . The transformer is used
to take a low voltage "pulsed square wave" generated by an inverter and
battery and convert it to an AC sine wave where voltage is regulated
1 to 5% depending on your requirement.
Sizes: The typical size range for this product would be 100VA through 25KVA
50Hz or 60Hz. However, we can produce inverter transformers with any VA
rating
Used primarily in brute force DC power supplies. The ferroresonant
transformer takes a sine wave input and creates a regulated square wave
output which is ideally suited for rectification. The square wave will
produce a lower ripple than a sign wave using the same filter capacitor.
Sizes: 25 watts to 10 kilowatts 50Hz, 60Hz, or 50/60Hz.
This takes a sine wave input and produces a sine wave output with a choice
of output voltage variations of 1, 3, or 5 % for an input voltage
variation of +10/-20%. These are used in an integrated power protection
systems, protecting the critical load from all power problems with the
exception of a blackout. Multiple voltages are available so this
transformer can replace a multi-tap input transformer.
Sizes: This product is available in sizes from 30VA through 75KVA single
phase or three phase 50hz or 60hz.
Similar to control transformers except they provide power to x-ray tube
filament. Typically, one requirement is very high dielectric strength from
the secondary to ground and from the primary to secondary.
Sizes: over 50VA minimum rating.
FERRITE CORE TRANSFORMERS
FERRORESONANT SQUARE-WAVE TRANSFORMER
FERRORESONANT TRANSFORMER FOR DC OUTPUT
FERRORESONANT TRANSFORMER SINE WAVE
FILAMENT TRANSFORMER
 | INDUCTORSAlso known as chokes, DC link, AC line/load reactors, and buck/boost inductors. Inductors are found in most electrical power conversion applications. Smoothing chokes are used to filter the AC ripple in a low-frequency DC power supply. Inductors are used to filter out RFI (Radio Frequency Interference). In another application they are used as current-limiting reactors for overload and short-circuit protection or to limit high inrush currents that might occur on the start up of an electric motor. |
Wide-band inductors are used at a multitude of frequency levels to filter out unwanted frequency noise leaving a clean fundamental signal. Inductors come in virtually all windings and constructions forms, dictated by the frequency and current they are to handle.
DC Filter Choke- Used primarily in filter applications or other tuned circuits. Can also be used in conjunction with capacitors to reduce ripple in DC circuits.
Swinging Choke- Similar to filter chokes except it has two inductance ratings at two currents.
AC Reactors - AC choke, line/ load reactors are used primarily to limit current. Both single phase and three phase versions are available. Also they can be designed for 50, 60 or 50/60Hz.
POWER TRANSFORMERS |
Power transformers includes insulating or isolating transformers. These
terms are used to describe the "electrical isolation" of the primary and
secondary windings, or insulation between the two. Often a electro-static
copper shield is placed between windings to reduce electrical noise from
primary to secondary. A grounded electro-static shield provides a safety
factor preventing accidental contact between windings under faulty
conditions. Sizes: These are available in single phase or three phase up to 250KVA. |
 | Also known as Dial-A-Watt. Used primarily with mercury vapor ballasts to vary the output current (power) to the lamp. |
TOROIDAL TRANSFORMERSToroidal transformers include power and auto-transformers, as well as inductors. Toroidal merely describes the geometric shape, similar to a donut. These transformer are typically more efficient because of the low core losses associated with a tape wound core, with no air gap. The shape also allows a larger portion of the copper windings to be exposed to the ambient air, enhancing cooling of the hotter copper windings versus the cooler iron core in a laminated transformer. A toroid, when compared to a stacked laminated type transformer, would be about 50% lighter and 50% lower in volume simply because it is more efficient. Other advantages include low stray field, low mechanical hum, reduced no load losses, easy mounting and flexible dimensions. |  |