On Mon, 3 Nov 1997 15:42:58 +200 "Chris R. Burger"
<CRB@knersus.nanoteq.co.za> writes:
>HAM IV ROTATOR PROBLEM SOLVED
>Only question remaining: must I really buy the 'proper' cap ? I used
>an
>old 100uF 100V electrolytic cap from my junk box and it seems to work
>fine. The 'proper' cap is approximately $ 15 from the local HyGain
>supplier. Can the electrolytic damage the motor ?
Electrolytics have a low breakdown voltage in the reverse
direction. There is a way to use two electrolytics
back-to-back, with shunting diodes, but you
would be better off buying a capacitor designed for AC use. In the
states, one can go to any motor shop and get a 120V AC capacitor for
about $4, but it will be physically larger than Hy-Gain's and will
have to be wired in. The capacitance value is not critical. Stay with
Hy-Gain's value, or the next larger size available. I remember doing
the phase shift calculations about 20 years ago to make that
determination, but remember only the general conclusion, not the
hard numbers of what values work.
Dave Hachadorian, K6LL
K6LL@juno.com
Yuma, AZ
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search
|