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Telrad flasher schematic

Started by kendo, 11/28/2007 03:55PM
Posted 11/28/2007 03:55PM Opening Post
I have looked for the article "A Pulsating Telrad Finder" on S&T 's site. But they only have the citation for it: John A Nevelus; Sky & Telescope; Dec 1988; 694; not the actual article.

Can anyone tell me what circuit was described? Send me a schematic?

Many thanks.
Posted 11/28/2007 06:27PM #1
Hi Ken,

Chances are it was based on the CMOS version of the 555 timer IC chip.

Here is a link to the operation:

It is a bit technical, but the equations are there to determine the pulsing rate you might want. The Telrad LED would hook up to the output pin 3 of the IC through the dimming resistor on the Telrad.

David Simons
Posted 11/29/2007 11:54AM #2
Ken Landaiche said:Can anyone tell me what circuit was described? Send me a schematic?
Ken: The attached schematic may help you.

Attached Image:

Herbert Kraus's attachment for post 118702

NexStar 8i SCT, Orion 80ED APO refractor, Orion 120 mm EQ refractor, 3.5-inch Questar
Posted 11/30/2007 06:04AM #3
Why not just buy a pulser kit like the ones Astrosystems and Scopestuff sell for $20? Mine works great. Of course, I understand that some folks just like to build their own.

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