CUSTOM DESIGNED MAINS TRANSFORMERS

Our standard offering includes up to 5 separate windings which may be any voltage up to 1000V rms and 600 Watts (VA). We can offer more than 5 windings at 5:00 UKPounds per addittional winding. In this case you must specify open frame or drop through type.  

Please indicate ("HV Insul") if low voltage windings are to be connected to high voltage supplies e.g. rectifier heaters. In this case we will fit high voltage lead-out wires.  

We are happy to provide center taps or other taps but please minimize the total number of connections as this causes assembly problems with style "S" particularly with multiple heater windings. Style "S" (Shrouded) is possible on the smaller sizes B,D,F and H only when a maximum of two secondary windings are used. More complex windings may be possible at additional charge. 

Electrostatic shields between the primary and secondary windings for mains noise isolation or between secondary windings are available at a small extra charge per shield.

We can incorporate an external "hum band" for a small extra charge.  This is a copper foil "shorted turn" round the outside of the transformer which will reduce the stray flux radiating from the transformer.  This is useful if the transformer has to be sited near tape heads or microphone transformers which can pick up hum.

Please check your specification values carefully as changes can lead to errors and delays.  If you find you need to make a change please email support quoting your design reference to cancel your specification and and resubmit a new one.  

Size/Power guide Size Approx power (Watts)

To obtain the total power in Watts (VA) simply multiply the voltage and current rating of each winding and add them together.  

The power rating in this table is a guide.  In general the rating may be increased perhaps by 10% if the secondary configuration is very simple.  Complex winding arrangements will usually reduce the rating by at least 10%. An electrostatic screen reduces the rating by 5%

If your spec comes out below the rating for a given size we will increase the wire size which will improve the regulation and reduce losses.

 

 

 B 10
D 15
F 25
H 35
I 40
J 50
L 100
K 125
M 150
N 200
P 300
P+ Encapsulated 200
Q 450
T 550
R 600

To see the prices for each size code see Price/Size Information

To see the dimensions of the size codes see Package Options

If you need help to specify HT windings with rectifier and filter options please click here.

E-MAIL FORM

Please use this form to send us your specification. We will E-Mail you with confirmation that we can make to your specification and the size code. If we cannot make to your spec we will suggest modifications.  With your spec reference and size code you will be able to order or quote at our online shop including shipping cost etc. You can order or quote multiple items to benefit from the lowest possible shipping cost. Please include your own reference such as "T1" etc. so that you can refer to it when you order or if there are any questions.

Your Name:
Your Email Address:
Country:
Delivery Address:
Local telephone (for possible shipping company use):

SPECIFICATION
Your reference (e.g. "T1"):
Primary:
Electrostatic screen (extra charge):
Hum band (extra charge):
Package style:
Secondary windings (Use format e.g. 350-0-350 V @ 3.5 A ):
Secondary 1:
Secondary 2:
Secondary 3:
Secondary 4:
Secondary 5:
Total V x A (should not exceed 600 Watts)*: 
Comments or special requirements:
Quantity:

* Please multiply the V x A for each secondary winding and add to get the total for all windings.  (You need to take the full voltage of a center tapped winding.  250-0-250 at 100 mA is 50 VA). This will enable you to obtain a guide price from the table above.  We use this number as a check when we do the quotation and the final design if you order.

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E A Sowter Ltd The Boatyard, Cullingham Road IPSWICH IP1 2EG England Tel: +44(0)1473 252794
Fax: +44(0)1473 236188