From bruce@ashbysolutions.com Wed Jan 02 13:14:43 2002
Subject:Re: SS Leslie Relay

Lon,

>Since I am about to replace the motor relay in my 122, could someone inform
>me as to the advantages of a SS relay over a stock one? The price
>difference is not significant ($32 vs $49). Why would I use one over the
>other?

A solid-state relay (SSR) is not actually a "relay" in the classic sense at all. It is a power semiconductor connected to a small electronic circuit that isolates the dangerous voltages from the input, just as a mechanical relay would. From a functional point of view, it looks like a relay. The advantages of a SSR are that it has no moving parts to wear out, and thus will last for decades, even under heavy use; and that it has very fast response.

However, a caution: An SSR is not a pin-for-pin compatible replacement for a relay; at least, I've never seen one made that way. To add an SSR to a Leslie, a small PC board with additional components is usually required. Without these components, you may destroy the SSR in a matter of minutes or hours. Now, it's possible that the entire setup is available in one package, but if so, $49 sounds like a very low price, IMHO.

Regards,

-BW

--
Bruce Wahler
Design Consultant
Ashby Solutions™ http://consult.ashbysolutions.com
CloneWheel Support Group and HiNote moderator
978.386.7389 voice/fax
bruce@ashbysolutions.com