Isolation transformer

dryhigh-voltagesurface-mount

Transformer Type: These supply 120V or 240V AC continuous power for equipment that must operate while at a high voltage to ground or power source. For example, a fiber optic transmitter at the HV level for waveforms to be received and measured or recorded by grounded instrumentation might be powered by an isolation transformer secondary to primary either insulated by potting, oil or air. The low dielectric constant of air insulation provides lower capacitive coupling between the secondary and the primary or ground than would solid or oil insulation. The lower capacitance provides better isolation both at line frequency and especially at high frequency voltages such as lightning or switching transients. Higher capacitance solid, oil filled or air insulated with capacitance values as low as 20 Picofarads and withstand voltages of 60kV peak or more are available. Ratings may be 50VA to 2kVA or more. Isolation ratings between secondary and primary or grounded power transformer core of 5kV powerclass up to 50kV RMS. 60kV or 110kV 1.2x50 microsecond impulse withstands are available. The most popular models for low power instrumentation are 50 volt amps or 500 volt amps with 115V/230V primary to 115V/230V secondary and withstand isolation of 30kV peak 1 minute and 60kV impulse.