Step-up / step-down transformer
STO toroidal step-up & step-down transformers
Step-up / step-down transformers wound on a toroidal (annular) iron core, which the catalogue describes as giving low power consumption and high efficiency.
4Catalogue models
500W – 2,000WCatalogue power range
39–40Catalogue pages
1989Goldsource founded
2Exterior 3D models
Reconstructed exterior
Every side,
square on.
Illustrative renders reconstructed from catalogue photographs; dimensions are estimated. Appearance and configuration may vary by version.
Interactive exterior
STO-500,
in the round.
Illustrative exterior model reconstructed from catalogue photographs. Appearance and configuration may vary by version.
Drag to rotate · Scroll to zoom
Illustrative exterior model. Appearance and configuration may vary by version; check against the current product specification.
Historical catalogue record
What the catalogue says.
What to confirm.
- Product category
- Step-up / step-down transformer
- Series
- STO
- Catalogue models
- 4
- Source
- Catalogue PDF pages 39–40
- Source
- DIYTrade listing (2025)
- Current specifications & availability
- Confirm by enquiry
Features as printed in the catalogue
- Input voltage: AC 110V or 220V
- Output voltage: AC 220V or 110V
- With fuse protector or with over-current protector
- Toroidal (annular) iron core
Catalogue values are historical reference information, not confirmed current specifications. Confirm the exact model, ratings, input range and certification status before ordering.
STO catalogue models.
| Model | Rated power | External package size | Net weight | Gross weight | Pieces per carton |
|---|---|---|---|---|---|
| STO-500 | 500W | 50.5 × 34.0 × 20.5 cm | 15.5 kg | 17.5 kg | 8 |
| STO-1000 | 1000W | 56.0 × 27.5 × 22.5 cm | 18.0 kg | 19.5 kg | 6 |
| STO-1500 | 1500W | 56.0 × 27.5 × 22.5 cm | 20.5 kg | 22.0 kg | 6 |
| STO-2000 | 2000W | 38.5 × 29.0 × 22.5 cm | 16.5 kg | 18.0 kg | 4 |
Sizes are external package sizes in cm; weights in kg; quantities are pieces per carton.
