Transformer 9-0-9V 30VA

The Transformer 9-0-9V 30VA is a centre-tapped step-down transformer with a 9-0-9 V secondary and a 30 VA power rating. It gives 9 V AC on each half of the secondary, or 18 V AC across the full winding. With three times the power of a 10 VA unit, it suits linear power supplies, dual-rail supplies for op-amps and small audio amplifiers that need more current.

Transformer 9-0-9V 30VA Specifications

• Secondary: 9-0-9 V AC, centre-tapped (9 V + 9 V)
• Full secondary: 18 V AC end to end
• Power rating: 30 VA
• Secondary current: about 1.6 A from the full 18 V winding (30 VA ÷ 18 V)
• Primary: AC mains; check the label for the rated input voltage
• Type: step-down transformer with a centre tap

Transformer 9-0-9V 30VA Applications

• Full-wave rectifiers using two diodes and the centre tap
• Dual-rail (positive and negative) supplies for op-amps and audio amplifiers
• Regulated supplies with a bridge rectifier and a 7805, or a 7812 from the full 18 V winding
• Low-voltage AC for electronics training and measurements
• Replacement transformer for amplifiers and small devices

What's in the Box

• 1 × 9-0-9 V 30 VA transformer

Tip: After rectification and a filter capacitor, each 9 V half gives about 12 V DC at light load (9 V × 1.41 minus the diode drop), so use filter capacitors rated at least 25 V. The primary connects to mains voltage: insulate all primary connections, add a fuse and never work on it while it is plugged in.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.