Toroidal Power Transformers

Toroidal power transformers are popular for their low radiated magnetic field and comparable size & weight to VA rating.  Advantages of a Toroidal Power Transformer over other types of transformer platforms are many.  This is especially true of Toroidal Power Transformers compared to typical laminated transformers. The advantages flow to the bottom line; improved performance and lower cost.  Learn more by viewing our webpage Advantages of Toroidal Power Transformers.

Bicron’s power range for Toroidal Power Transformers covers 20VA to 10,000VA.  Choose from our selection table below for a Standard Toroidal Power Transformer model or complete and return our Toroidal Power Transformer Design Worksheet to specify the custom transformer model that meets your needs.

Whether you select a standard or custom model we will contact you directly to review all performance requirements needed to complete a quotation. Common factors we will review with you include size, power, rating, mounting, height/diameter ratio, lead configuration, agency approval type, insulation and shielding.   

Visit our Technical Guide for Bicron Toroidal Power Transformers for design and application criteria important to the use of our products.

Please clarify your choices from the following options when selecting a Bicron Toroidal Power Transformer:

  • Bicron Safety agency recognitions include Consumer Electronics UL6500 & IEC60065; General Purpose UL506; Medical UL60601-1.
  • Bicron recognized insulation systems: Class B 130°C; Class F 155°C; Class H 180°C.
  • Input voltage; 120V or 120/240V.
  • Secondary voltage; 120V or 240V, or custom voltage. 
  • Secondary; single or dual output.
  • Frequency; 50/60Hz or 60Hz.
  • Temperature range.
  • Mounting styles; Type 1, Type 2, Type 3 or Type 4 (see below).
  • Quantity required.
  • See Figure 11, below, for a sampling of winding and connection alternatives
  • Technical notes, below.

Standard Toroidal Power Transformers

Part Number50/60Hz Power (VA)Regulation Full Load (%)60Hz Power (VA)Approx. OD (in.)Approx. Height (in.)Approx Weight (lbs)Datasheet
BEC-TPT1012025242.71.50.80
BEC-TPT1023025362.71.91.20
BEC-TPT1034020483.51.51.5
BEC-TPT1046015723.51.81.9
BEC-TPT1058013964.21.72.1
BEC-TPT106100111204.21.92.3
BEC-TPT107160102004.72.03.1
BEC-TPT10823082754.72.55.5
BEC-TPT10933074004.83.16.8
BEC-TPT11040074805.72.67.5
BEC-TPT11153066405.75.29.8
BEC-TPT11260057205.73.511
BEC-TPT11375059006.33.513
BEC-TPT1141000512006.33.816
BEC-TPT1151200514406.34.518
BEC-TPT1161500518007.93.521
BEC-TPT1172000524007.94.128
BEC-TPT1182500430008.15.134.5
BEC-TPT119300048.35.336.5
BEC-TPT1205000
BEC-TPT1216000
BEC-TPT1227000
BEC-TPT1238000
BEC-TPT1249000
BEC-TPT12510000

Toroidal Power Transformers with power up to 10,000VA are available in configurations modified for size, input/output values, leads, shielding, mounting and other considerations.  Please use our Toroidal Power Transformer Design Worksheet to specify your requirements and request a quote.

Winding & Connection Alternatives

Technical Notes

LINEAR POWER SUPPLY DESIGN
Typically, there are three system configura­tions used in conjunction with linear power supplies. The half wave (HW), the full wave (FW), and the full wave center tap (FWCT). Each configuration will have impact on the VA requirements of the transformer and the circuit components comprising the rec­tification and filtering. Please contact Bicron engineering for specific transformer parameters.

THREE PHASE SYSTEM BASICS
Three single phase transformers may be connected to form a 3-phase bank in the configurations shown. Also shown are the voltages and currents based on ideal con­ditions. The VA rating of each transformer is one third the total system regardless of the selected configuration. The voltage and current ratings of each transformer is, how­ever, configuration dependent.

AUTOTRANSFORMER BASICS
The same transformation of voltage and current can be obtained with a single winding autotransformer as with the nor­mal two winding transformer. There are two major differences:

  1. In the autotransformer, the secondary winding is common to both the primary and secondary wind­ing.
  2. There is a direct copper con­nection between the primary and sec­ondary circuits.
Autotransformers have lower leakage reactance, lower losses, smaller excitation currents, and they can be smaller and less expensive than dual winding transformers when the voltage ratio is less than 2:1. And, of course, they provide no isolation.
 
THERMAL CLASS
Thermal class is designated by a letter and defines the lowest temperature rating of the materials which make-up the trans­former:
Class A materials (105°C)
Class B materials (130°C)
Class F materials (155°C)
Class H materials (180°C)
 
TEMPERATURE RISE
The temperature rise of a transformer can be determined by the resistance method:
t = ((R22R1)/ R1)3(234.52t2) 2 (t22t1)
t = temperature rise over ambient, t2 (°C)
R2 = resistance of winding at end of test
R1= resistance of winding at beginning of test
t2= ambient temperature at end of test (°C)
t1= ambient temperature at beginning of test (°C)

CUSTOM POWER TRANSFORMERS

Bicron Electronics features power transformer designs for high-frequency applications including “corona-free” technology and high isolation, and toroidal power transformers up to 10KVA. Our current sensing transformers are high-efficiency and include self-energized models for switchgear and power distribution monitoring applications.