Ex workshop spare parts and R&D/manufacturing stock
ALL components were sourced through reputable local distributors such as RS Electronics, Farnell, WES and Rockby (Victoria) or direct from the manufacturer.
Old stock, around the early 2000's!
HARBUCH ELECTRONICS - Toroidal Power Transformer
Made in Australia (Sydney)
I suspect Harbuch is going through a period of "transition" as their website appears to be only partially active and I read somewhere that the original owner (Rod) was retiring
Model: PTT-5458
625VA Total power output capable
Label on one side of the core reads:
HARBUCH ELECTRONICS PTY LTD
PTT-5458 625VA
PRIM 240V ORG-ORG
SEC 1: 2x 50V/6A RED-YEL & BLU-GRY
SEC 2: 2x 15V/.8A GRN-VLT & BLK-WHT
(Old Australian Made "Boomerang" graphic sticker to the right side)
Quad (Fully isolated) secondaries:
50V @ 300VA (around 6A full load) - typically for audio power amplifier output stages
15V @ 800mA - typically for auxiliary modules, input stages (particularly those based on Op amps with dual rail supplies)
Orange - Orange: 240V AC Primary winding (not multi-tap, just 240V input)
Secondary 1 : .Red & Yellow
Secondary 1a: .Blue & Grey
Secondary 2 : Green & Violet THIS IS NOT CORRECT!!!!
The label indicates these colours but THEY DO NOT EXIST! Looks as though QC failed and the colours actually used for this one 15V winding are BROWN & ORANGE - yes the Primary windings are also Orange but it is easy to see which are the primary windings and which is the secondary winding (physically separated to start with)
So don't go hunting for a Green & Violet coloured wire, they do not exist!
ALL other colours are correct as indicated on the label.
Secondary 2a: .Black & White
. indicates "start of winding"
NOTE: I currently have just two of these toroids left, BOTH ARE POTTED as described below under DIMENSIONS
SPECIAL NOTE:
The astute observer may notice a Yellow/Green wire along with the two Orange primary wires. I have confirmed this is not electrically connected to any other winding and it is not mentioned on the manufacturer's labelling,
Although not commonly found on toroid transformers, I have found other manufacturers in USA and Canada who produce toroids with these shield wires. The idea is to take this wire to Ground and this should help reduce "HF noise" reduction - it may be a case of experimentation here (whether to use this wire or not)
Here is a rough diagram of where this wire sits in the scheme of things, unfortunately I have no idea how Harbuch created the shield internally though
NO mounting hardware supplied (rubber or plastic discs, metal disc and central bolt) with either of these transformers.
DIMENSIONS:
140mm diameter x 70mm height
Central area of the transformer is epoxy filled BUT with a recessed "top entry". If looking down into the central area, it is formed like a tube 25mm diameter with a depth of only 15mm. The central hole for the bolt (8mm diameter) begins at the base of this tube and continues to the other side of the transformer, meaning you need a bolt around 7.5 ~ 8mm diameter and 55mm length (70mm height toroid core less 15mm) The head of this bolt can be up to 25mm diameter (same as the tube that the bolt would sit inside)
All primary & secondary flying leads 200mm length
All leads are solid core EXCEPT the Yellow/Green Shield wire which is multi-strand - all insulation used is PVC.
WEIGHT:
5.5Kg !!! Compact but very heavy - wear safety boots when carrying these! The Post Office jokes that I am sending Gold bricks in the Post when these are passed over the counter ....
COSMETIC CONDITION:
NEW
Old Stock
TESTING:
To confirm the transformer is functioning properly, I have made some simple "open circuit/no load" tests ON EACH transformer being offered.
Secondary 1 & 2: 51.1 ~ 51.8V each (slight variation between the two potted toroids)
Secondary 3 & 4: 15.4 ~ 15.7V each (slight variation between the two potted toroids)
The Yellow/Green wire has been confirmed as NOT electrically connected to any other winding - infinity reading between this wire and all others (primary & secondary)
Confirmed total isolation between Primary & Secondary windings and all secondaries are separate windings.
PRICING: I am a bit "out of touch" with current market prices but I know we paid around my asking price for these transformers years ago. I see the current prices from reputable distributors is somewhere between A$175 ~ A$300 so my price still represents a signifcant saving and as I am far more interested in these HEAVY transformers to go "out the door", substantial discounts automatically apply for quantity purchases.
