[Boatanchors] small power transformer needed

[rbethman]

Y'all have missed the boat!

He has already found his solution, and it certainly isn't this methodology!

Bob - N0DGN



On 7/15/2014 9:51 AM, Brian Clarke wrote:
> Oh dear NO!!!
>
> Robert's idea is incredibly dangerous. Any slight leak and the only 
> current limiting you really have is back at your electrical mains 
> distribution board - perhaps 30 A.
>
> The other major problem you have is that you ideally want the bias to 
> be with respect to the ground in your radio chassis. Such a ground 
> will usually be connected to the grounding wire in your mains lead, 
> which in turn, back at the distribution board, will be connected to 
> the Neutral. The neutral is connected to one side of your bridge 
> rectifier. A bridge rectifier cannot therefore give you a bias Voltage 
> that can be grounded in your radio.
>
> The only way you can safely use Robert's idea is for a temporary 
> electric chair. Temporary? You may only use it once. After that, 
> safety will be irrelevant.
>
> Keep looking for an isolating transformer.
>
> 73 de Brian, VK2GCE.
>
> On Tuesday, July 15, 2014 10:50 PM, Robert Moses declared:
>
>
>> One solution might be to do away with the transformer altogether: From
>> the '120' V line feed run it through a full wave bridge, then a current
>> limiting resistor, and finally a large electrolytic capacitor. This will
>> tend to charge the capacitor to the RMS voltage of about 165V. If you
>> are dropping the DC voltage down to 95 to 125 volts this should give you
>> enough to feed your dropping circuit. (BTW a 1 - 10 meg bleed off
>> resistor across the capacitor is not a bad idea.)
>