Transformer 9-0-9V 3VA

The Transformer 9-0-9V 3VA is a small step-down transformer with a centre-tapped secondary that gives 9 V AC on each side of the centre tap and 18 V AC across the outer wires. With a 3 VA rating it is meant for low-current circuits such as microcontroller boards, timers and sensor modules, where a compact transformer is all you need.

Transformer 9-0-9V 3VA Specifications

• Secondary voltage: 9-0-9 V AC, centre-tapped (18 V AC end to end)
• Power rating: 3 VA
• Secondary current: about 165 mA across the full 18 V winding (3 VA ÷ 18 V)
• Rectified output: roughly 12 V DC per half after a rectifier and smoothing capacitor, higher with no load
• Operation: AC only; a transformer does not work from a DC source

Transformer 9-0-9V 3VA Applications

• Small regulated supplies with 7805 or 78L05 regulators
• Powering microcontroller, timer and sensor circuits
• Low-current auxiliary or standby supplies on control boards
• Mains-frequency (50 Hz) reference for zero-cross detection and clocks
• Replacement part in appliance and electronics repairs

What's in the Box

• 1 × 9-0-9 V 3 VA transformer

Tip: Keep the load within the rating: at 3 VA the transformer supplies only about 165 mA, so it is not suited to motors, high-power LEDs or several relays at once. Check that the primary rating on the label matches your mains (220–230 V in Lebanon) and insulate the primary connections.

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