How to get a quote for a custom designed choke

Please specify the inductance and DC current capability you need. You can also specify the D.C. resistance or leave this to us. In this case it will be determined by the current rating of the wire but we will thicken up the wire to minimize the resistance if we have space on the bobbin. If you specify a resistance value the choke may be larger. We can design chokes for choke input or capacitor input filters. If you specify a choke for a choke input filter we need to know the rms ac voltage feeding the rectifier output as the choke must support this voltage. The choke in a capacitor input filter only sees a small ripple voltage. Chokes for choke input filters are generally at least 50% larger.

We regret it is not possible to make chokes with a Drop-Through package style. There is an extra charge if you require the Fully Shrouded style.

We can also make plate (anode) chokes for use with parafeed output stages. They are similar to single ended output transformers with no secondary. Plate chokes are wound using inter layer insulation and a two chamber bobbin to increase the self resonance frequency. There is an extra charge for this option.


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:
Delivery Address:
Local telephone (for possible shipping company use):


Your reference
(e.g. "C1"):
AC voltage if used as choke input filter or plate choke(V):
Inductance (Henrys):
DC Current (mA):
DC Resistance (ohms). We will optimize if you do not specify:
Package style:
Comments or special requirements:

To confirm you are not a robot PLEASE TYPE THE ABOVE 5 DIGIT NUMBER:

EA Sowter Ltd Carnhill Transformers
5 Burrel Road, St Ives, Cambridgeshire
PE27 3LE United Kingdom
Tel: +44(0)1480 462978
Fax: +44(0)1480 496196