From goff747@aol.com Thu Dec 25 18:16:27 2003
Subject:Re: Speed Control Pedal


In a message dated 12/26/03 9:56:01 AM, claire_trikes_aust@iprimus.com.au
writes:

<< Dan and Ron,

Thanks for your common sense with this Leslie speed varying thing.

May I summarise:

a) Running mains through any pedal not designed for mains voltages WILL be

a potential ELECTROCUTION HAZARD.

b) Running the amount of current required by just about any motor through a

carbon pot will DESTROY it - definitely smoke, possibly fire.

c) Running mains voltages through any connectors not designed for it (eg

audio connectors etc.) will almost definitely constitute a FIRE *AND*

ELECTROCUTION hazard. (You can get away with it if you know what you are

doing, but it is not recommended for physical , insulation and current

carrying reasons- some mentioned in the previous email.)

(By the way, there is a range of XLR connectors specifically designed for

mains voltages and currents. They are the same external size as audio XLR

connectors but they have a RED insulation insert around the pins and larger

(and incompatible) pins to all other types of connectors.)

d) There is no easy way to control the speed of motors that are not

designed for variable speed. Eg Witness the synchronous motor that Hammonds

are famous for. It will run at a CONSTANT speed independent of normal

variations in mains voltages. (That's the whole point). Brush-type motor

speed can be changed by varying the *Average* voltage. This is normally

achieved by a Pulse Width Modulation controller such as a normal lamp

dimmer. This will NOT work with brushless or synchronous motors and will

probably present a burn out/fire hazard for both controller and motor.

Sorry about the capitals but I wouldn't want anybody on this list to be

burned or electrocuted by the absolutely unsound suggestion of running mains

through a normal carbon pot type volume pedal.

Merry New Year to all. (have a safe one !)

Cheers !

Claire

Australia >>

more light at the end of the tunnel....