[GreenKeys] Re: Voltage and Current

[Bob Camp]

Hi

Should have been more specific. The switcher has a 12 volt input and  
a variable output.

Bob


On Jan 23, 2007, at 11:36 PM, WA5CAB at cs.com wrote:

> EE Mode On.
>
> 12 volt constant current supply is a contradiction in terms, at  
> least in the
> context of this group where most machines run on loops @ either 20  
> or 60 mA.
> Or to put it another way, a 12 volt supply with electronically  
> controlled
> series resistance (i.e., a current regulator) will not push a  
> square wave current
> wave form through either M15 or M28 holding magnets.  Consequently,  
> the error
> rate will go sky high and the range will go to zilch.
>
> EE Mode off.
> Greasy fingered tech mode on.
> It won't work.
>
> In a message dated 1/23/2007 9:47:21 PM Central Standard Time,
> drhouse at nadcomm.com writes:
>> Bob,
>>
>> 48 volts should be the minimum used to operate selector magnets.
>> Personally I prefer -130vdc 62.5 ma but you know that I suppose.
>>
>> Don
>> K9TTY
>>
>>
>> On 23 Jan 2007, at 8:42 PM, Bob Camp wrote:
>>
>> Hi
>>
>> A typical constant current loop control transistor puts a fixed bias
>> on the base (or gate) and resistance from the emitter (or source) to
>> the other side of the bias. As the current in the resistor drops the
>> current in the transistor increases.
>>
>> These days you can do some interesting things with a switching
>> regulator. Twelve volt supply constant current loops anybody?
>>
>>
>
> Robert & Susan Downs - Houston
> <http://www.wa5cab.com> (Web Store)
> MVPA 9480
> <wa5cab at cs.com> (Primary email)
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