Re: Timed Release?

[P3D John W Roberts <roberts@xxxxxxxxxxxxxxxxx>]

>Date: Thu, 25 Sep 1997 18:59:26 -0500
>From: P3D Bill Davis  <bd3d@xxxxxxxxxxxxx>
>Subject: Timed Release?

>Does there exist a device that allows adjustable duration shutter release?  

>...Is there anything like this available which *holds* the shutter open for an
>adjustable length of time?  

>...What about shorter times, like a few seconds or less (1/2, 1/10)?

An adjustable-length "one-shot" circuit, driving a solenoid, which activates
the shutter ("B" setting).

Unfortunately, I know very little about driving a solenoid. You'd use power
transistors, and probably some diodes somewhere in the circuit (to keep the
inductance of the solenoid from blowing out the transistors?).

"Nuts & Volts" magazine probably has circuit diagrams of this type every
now and then.

John R


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