CANFORD AC MAINS POWER TRANSFORMERS
Perhaps these specialist transformers are an unexpected inclusion, but hopefully of help to OEM’s and project builders.
Toroidal transformer 60VA dual 0-12V
A general purpose toroidal mains transformer, with twin primary and secondary windings. Primaries are 0-120V, secondaries are 0-12V rated 2.5A, both can be connected series or parallel. Secondary open circuit voltage 13.6V. Lead lengths 250mm. Dimensions: 83mm (diameter), 37mm (height excluding mountings). Supplied with mounting kit, comprising 2 x 70mm pad, 1 x 70mm clamp plus M6 x 45 screw and M6 nut.
Microphone amplifier mains transformer
This toroidal transformer is intended to provide, in conjunction with bridge rectification and smoothing capacitors, a dual rail, 40mA, 15V DC supply, with an additional winding to provide, with suitable additional components, a 20mA phantom (P48) supply.
The toroid is terminated with 130mm flying leads, the wound core is wrapped using a grain-orientated silicon steel screen to reduce external "hum" field. Fixing is by a single M4 insert centrally embedded in resin, with attached foam rubber washer.
This high performance transformer is commisioned from a leading (EC) supplier of audio related transformers to Canford specifications. Examination of the technical specification of the Canford Mains powered microphone preamplifier will give some guide as to achievable performance in terms of hum and noise.
Technical Specification:
| Primary: |
110-0, 110-0 (yellow-orange, white-blue) |
| Secondary: |
17.6V - 0 - 17.6V, (red-green-red), 60mA |
| Secondary: |
44.4V - 0, (black-grey), 30mA |
| Dimensions: |
62 (diam.) ×33 (h)mm (max.) |
| Conformance: |
Manufactured in accordance with BS415 |
Application note: The design is based on the use of a separate bridge rectifier for each of the two secondaries, and 470µF (×2), and 100µF smoothing capacitors for secondary 1 and 2 respectively.