Re: ATM RE: Solar Scheifspiegler?

["Chris Westland" <westland@uxmail.ust.hk>]

 BTW, on the issue of solar scopes,  I had an exchange will Del Stanton
earlier on this list about guidance systems.  Rather than rely on expensive
clock drives and GEMs, there is a cheap and simple window comparator circuit
which keeps a drive motor (cheap geared model motoer with max current of
300mA) idle as long as two light-dependent resistors are receiving the same
illumination.   Mount the scope on an al-az mount, put paper towell rolls as
cylinders over the tops of the LDRs (two for each axis).  The drive for each
axis requires two LDRs, a geared motor, two BD239 and 2 BD 240 (NPN and PNP
transistors) 4 small diodes (IN4001) and a LM324.  It runs off of a 12 volt
battery (9 to 15 VDC).   I'll send you the drive circuit if you are
interested.

Chris Westland
Hong Kong

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