Roger's Universal Transformer
Designed by
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The low leakage symmetrical wound KE87060 power transformer, which originally was designed for use as a combined Williamson Tube Mains & Output transformer, has the following design parameters:

Primary windings (236VA@design, 290VA using all primaries):
- 4X115V@40Hz (Imax=1.1A)
Secondary windings:
- 2X350V@0.15A (U0=383V, Imax=0.3A)
- 4X6.3V@4A (U0=7.0V, Imax=4A)
- 2X5V@3A (U0=5.5V, Imax=4A)
Miscellaneous data:
Dimensions/Weight: 66X140mm/4kg
Primary inductance: 65H@5V/50Hz (75H@13V, 32H@660V)
Primary leakage inductance: 100mH (20kHz@KT66 drive, osc!)
Primary inductance vs DC unbalance: 26H@+/-7mA/13V (7H@+/-24mA)
Primary DC resistance: 24Ohm
Secondary HV inductance: 135H@5V/50Hz (152H@13V, 73H@1kV)
Secondary HV leakage inductance: 50mH (40kHz@KT66, ok!)
Secondary HV inductance vs DC unbalance: 37H@+/-7mA/13V (12H@+/-22mA)
Secondary HV DC resistance: 90Ohm
Effective std rectifier drive impedance: 33+45=78Ohm

KE87060, Roger's Universal Transformer

Which makes the transformer useful as for instance:
- Universal 235VA Tube Mains Transformer (typically RC-filtered 450Vdc@150mA, each channel)
- Standard Universal High Power Tube Output Transformer with 50% taps (230V@20Hz push-pull)
- Optional High Voltage Tube Output Transformer using S7&S8 along with P1-P4 (580V@20Hz push-pull)
- Ordinary 2X30V/4A+5V/8A DC-Supply Transformer (special rectification)
- 235VA 115:230V Step-Up/Down Transformer (for American users or equipment)
- 100VA 12.6:230V Push-Pull DC/AC-Conversion (for portable usage)
- 235VA Mains Isolation Transformer (for TV-service)
- Low price: 160USD

More info:
KE87060, Taps
KE87060, Using my UNI as an OPT
KE87060, Using my UNI as an MT
KE87060, Static UNI Loss Model
KE87060, Primary stepresponse
KE87060, HV windings stepresponse
KE87060, Primary inductance vs push-pull voltage
KE87060, Primary inductance vs DC unbalance
KE87060, Main transformer configurations
KE87060, Output transformer configurations
KUC-00A, Simple PWM DC to AC/DC Converter