Step2: Power transformer connections

Description of connections of secondary and primary of power transformer

LED connected via resistor to green () heater wires of driver socket.

Rectifier socket connection. Brown () are heaters wires. Yellow () high tension. 82 ohm / 4 W resistor.

Overview of twisted secondary wires. Green () heater wires of driver socket where to short as you can see from the connection.

Orange () and red wires () to rectifier bridge for 5 V heater of 300B socket.

Primary connections

There are 2 pairs of primary wires. I call the 2 main primary windings P1 and P2 (2 x (0-110V-120V)

  • P1 = 1 blue (0V), 1 gree (110V), 1 red (120V)
  • P2 = 1 blue (0V), 1 gree (110V), 1 red (120V)

This is the connections for 230 V.

  • P1 blue -> mains connector (IEC socket)
  • P2 red -> middle of on/off switch (and then from the top switch connection to the other mains connector)
  • P1 green to P2 blue
  • P1 red and P2 green remain free in the 230V configuration

End of Step 2

Click on image to see full size