Voltage Transformer

A Voltage Transformer (VT) is a device which converts energy of one form to another. VT’s are used to monitor alternating AC or DC current by measuring voltage directly or through a VT. Voltage Transformers are a parallel connected type of instrument transformer. They are designed to present negligible load to the supply being measured.  They have an accurate voltage ratio and phase relationship to enable accurate secondary connected metering.

dc voltage transformer

DVT-1000 DC Voltage Transducer

DVT-1000 DC Voltage Sensor is designed to convert a 10-1000 DC Voltage input to either a 4-20mA output or a voltage standard output

voltage sensor

SPT-0375 Voltage Transformer

The SPT-0375 voltage transformer is a potential transformer – It offers output AC voltage that is linearly proportional to the AC voltage input. 

dvt voltage

DVT-100 DC Voltage Transducer

The DVT-100 DC Voltage Transducer is designed to convert a 1-100 DC Voltage input to either a 4-20mA output or a voltage standard output that is proportional to the input. 

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There are two basic solutions within Voltage Transformers – A potential transformer (PT) has an iron-core construction. A capacitor coupling voltage transformers (CVTs) lowers the voltage level first and then use the iron-core transformer to get further reduction in voltage by using a capacitor coupling principle. The two of these transformer types are usually free-standing.

Voltage Transformers

Voltage Transformer Types

  • Electromagnetic – The electromagnetic potential transformer is a wire-wound transformer.
  • Capacitor – Voltage transformers (CVT) use a capacitance potential divider using higher voltages due to lower costs than an electromagnetic VT’s.
  • Optical – An optical voltage transformers make use of the Faraday effect which rotates polarised light in optical materials.

The potential transformer is often used to measure the voltages at substation busses. However the CVTs can be used for the same measurement purposes on transmission lines individually. The transformers are used to bring the voltages down to an acceptable level used by protective relays because the power systems voltage levels range well above kilovolt values.

voltage transformer

DC Voltage Transformer

The DVT-1000 DC Voltage Transformer is designed to convert a 10-1000 DC Voltage input to either a 4-20mA output or a voltage standard output that is proportional to the input. It is also perfect for solar-string voltage monitoring. The DC Voltage transformer provides effective and safe isolation between the input and output.


  • Primary voltage DVT-100: 1000-10,000 Vdc
  • Output 4-20mA, 0-1Vdc, 0-5Vdc
  • Accuracy: 1% over range
  • Linearity: 0.5% over range
  • Response time: 10.0 mSec
  • Working Range: 0-120%
  • Overload: 150% continuous
  • Temperature: -30 degrees C to 70 degrees C operating
  • Humidity: 90% operating
  • Isolution: 4.5KV, 1 Minute
  • Supply voltage: 15-48 Vdc


The Voltage Sensor is typically described by its voltage ratio from primary to secondary. Meaning a 500:120 PT provides an output voltage of 120 volts when 500 volts are input across its primary winding. We are a trusted supplier of Magnelab Voltage Transformers. See our VT range here.

The VT is seen as an electrical component instead of an electronic component. A transformer is a very simple static electro-magnetic passive electrical device that works by converting electrical energy from one value to another.

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