Transformer for a lamp, led converter, and transformer operation method

A converter with electrical isolation, which is configured to supply power to a light-emitting means (3;

• 5), the converter comprising:
• a primary-side circuit (20;
• 60;
• 90;
• 100) having a half-bridge circuit, which has two alternately clocked switches (21, 22), and having a resonant circuit (25-27;
• 25, 26, 28), which is coupled to a node between the two switches (21, 22), wherein the resonant circuit (25-27;
• 25, 26, 28) comprises:
• an LLC resonant circuit (25-27;
• 25, 26, 28), a secondary-side circuit (30) with an output (35) for supplying energy to the light-emitting means (3;
• 5), and
• a control device (14), which is configured to control the half-bridge circuit depending on a controlled variable (ipeak) detected in the primary-side circuit (20;
• 60;
• 90;
• 100) in order to regulate a current intensity provided at the light-emitting means (3;
• 5) by the secondary-side circuit (30) to a setpoint value.