Transformer 18-0-18V 20VA

The Transformer 18-0-18V 20VA is a centre-tapped step-down transformer with an 18-0-18 V secondary and a 20 VA power rating. It gives 18 V AC on each half of the secondary, or 36 V AC across the full winding. It is a good match for ±15 V op-amp supplies, preamplifiers, small audio amplifiers and linear power supplies that need a moderate amount of power.

Transformer 18-0-18V 20VA Specifications

• Secondary: 18-0-18 V AC, centre-tapped (18 V + 18 V)
• Full secondary: 36 V AC end to end
• Power rating: 20 VA
• Secondary current: about 0.55 A from the full 36 V winding (20 VA ÷ 36 V)
• Primary: AC mains; check the label for the rated input voltage
• Type: step-down transformer with a centre tap

Transformer 18-0-18V 20VA Applications

• Regulated ±15 V supplies for op-amps with 7815 and 7915 regulators
• Dual-rail supplies for preamplifiers and small audio amplifiers
• Full-wave rectifiers using two diodes and the centre tap
• Linear power supplies and electronics training benches
• Replacement transformer for amplifiers and small devices

What's in the Box

• 1 × 18-0-18 V 20 VA transformer

Tip: After rectification and a filter capacitor, each 18 V half gives about 24 V DC at light load (18 V × 1.41 minus the diode drop), so use filter capacitors rated at least 35 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.