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From: legg <legg@nospam.magma.ca>
Newsgroups: sci.electronics.repair
Subject: Re: Voltage halver.
Date: Thu, 04 Apr 2024 10:12:13 -0400
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On 03 Apr 2024 12:07:10 -0700, peter@easthope.ca wrote:

>A variable power adapter is required to drive a 6 V, 30 W incandescent 
>bulb in a microscope.
>
>Similar to the 3-12 V 5 A adapter here.
>https://www.ebay.ca/itm/305207182573
>An adapter providing 1.5-6 V output would be better but I haven't 
>found one.
>
>Rather than limit the adjustment to 6 V, I think of halving the 
>output.  An integrated circuit in a 4 port package is conceivable.
>https://www.youtube.com/watch?v=VJfqBQ2ybpk
>
>Does the marketplace offer a solution?
>Another idea?
>
>Thanks,                  ... P.
>
>
What does the microscope manufacturer supply for this function?

If you have a >6V source, simple 555-type buck regulators are 
 available with minimum output listed as 1.8V

https://www.aliexpress.com/item/1005006482720286.html?

These generally regulate the negative output terminal, unfiltered.
This would not be an issue for an isolated 6V incandescent lamp.

Rl