diyAudio (
-   Equipment & Tools (
-   -   How to determine Current requirements of Bench Power Supplies for Fieldcoil speakers? (

ZERO1 16th January 2013 05:24 AM

How to determine Current requirements of Bench Power Supplies for Fieldcoil speakers?

I want to use 2-4 identical model vintage fieldcoil woofers in my system, 2 for the midbass horns and 2 for the stereo basshorns.

Each fieldcoil has an impedance of approximately 5200ohms and can dissipate 25 watts.

This website utility calculates the Voltage requirements for a given fieldcoil speaker (which in this case works out to 361V per woofer).

Field Coil Power Module at Ted Weber's Site

I'm looking for the right bench power supply with variable voltage and variable current.

1) My problem is I do not know how to calculate how much current (amperes) I need per woofer (?).

2) Also, I've read you can wire multiple fieldcoil speakers in Series to a single power supply provided the PS has enough current for the combined load. If I can wire up in Series the fieldcoil connections of 2 or 4 of these FC woofers, it could save me from having to buy a separate PS for each woofer.

So these are the two reasons I need to know how to determine how much current a given PS needs to have to provide power to my 5200ohm 25watt dissipation FC woofers.

Thank you in advance for any assistance.


RJM1 16th January 2013 08:13 AM

361V at 5200Ω, 361/5200=.0694 Amps. Aprx. 70 mA per woofer. It would be better to put the field coils in parallel than in series as you would need 722V at 70ma for two speakers or 1444V at 70ma for four speakers with the field coils in series. If you put the four speakers in parallel you would need a 361V 280mA (4*70mA) power supply, still deadly but 600V wire is a lot cheaper than 1500V wire.

All times are GMT. The time now is 10:49 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2