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From: peter@easthope.ca
Newsgroups: sci.electronics.repair
Subject: Re (2): Voltage halver.
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Date: 03 Apr 2024 17:32:23 -0700
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Roger Hayter <roger@hayter.org> wrote:
> I thought of that, but it is not very useful to adjust while looking down the
> microscope and I wondered if AC might affect microphotography.  Have you seen
> the price of 30W WW pots or "rheostats"?

Certainly adjustment while looking down the scope must be convenient.

Input voltage is another factor I should have mentioned. The scope is 
going to Africa where the wall socket will probably be 220 V. The 3-12 V 
adapter I have accepts 110-240 V input.  Good.

6 V is roughly the bottom 1/8 th of the range of the adapter.  Halving 
the output with efficient switching would allow use of the full range 
of adjustment.

I was hoping someone would cite a voltage halver as simple as this.
https://www.ebay.ca/itm/404142157480

Soldering leads to an IC would be a reasonable 2nd possibility.

Thx,                                ... P.