[R-390] OT: 30V regulator?

[DW Holtman]

Hello,

Don't forget about the simplest regulator around, the good old Zener. Digi 
Key sells a 1 watt 50 volt zener (1N4757ADICT-ND) for $0.36 in quanity of 1. 
They are available in voltages from 1.8 to 200 volts. They are simple and 
almost fool proof.

Best,
DW Holtman
WB7SSN

----- Original Message ----- 
From: "kenny" <igloo99nz at yahoo.co.nz>
To: <r-390 at mailman.qth.net>
Sent: Monday, September 17, 2007 3:22 PM
Subject: Re: [R-390] OT: 30V regulator?


> Barry wrote:
>> I was thinking of a 24VAC xfmr with a full-wave bridge, a cap, and 
>> possibly a 3-terminal regulator but didn't know if a 30V 3-terminal 
>> regulator is available.  Also, would like to make a 1.5V power supply for 
>> the D cell, but not sure if a 1 or 1.5 xfmr could be had as well as 
>> whether a 1.5V regulator is available.
>>
>> Any thoughts?
>>
>>
> I have recently been searching for a Voltage Regulator for a 50-volt 
> supply that I want to build. So far I have had no luck at all and may have 
> to consider using transistors to help with regulation although on the 
> circuit that I found one of the author's first comments was "the 
> regulation is not as good as with a IC regulator" so I'm probably back to 
> the drawing board on that one.
>
> Someone suggested the LM317...Yes I would agree. They are cheap and easy 
> to obtain and you can adjust the voltage. Even though the 30-volts is only 
> used on the high-ohms range I would go ahead and build it if I were you as 
> it would bug me if I had a piece of equipment that I couldn't get full use 
> of (I expect many of us are like that that's part of the reason we embark 
> on restoring our BA's). Regarding the 1.5-volt supply...I don't recall the 
> type numbers because during my search 1.5-volts did not interest me but I 
> did notice many regulators that can be adjusted down to this voltage.
>
> Regarding the supply that I want to build...My wishlist is for it to be 
> fully regulated and stable 50V and adjustable over a small range 48-51V. I 
> don't want to buy one, I want to build one but I just cannot find a 
> suitable regulator. Anyone have any ideas on where I can find a regulator 
> for this voltage OR a really good transistor (Bipolar or FET) circuit?
>
> Regards,
>
> Ken
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