Hello folks! I just joined the group yesterday night and have enjoyed browsing through the archives.
To business: I have the unenviable task of getting a new V21bis ( don't laugh!!! ) embedded MODEM through TBR-21 testing at what was Assessment Services in Swindon on the 3rd August ( TUV - sounds about right? ). I am more than a little worried about my Gyrator. The 50V thru 230R test is going to waste my existing design, even though as a matter of course I have almost always included an I-limit of 60mA where I was able to, however, 2.2W is not going to do a BCX38 any good... Can anyone please suggest a suitable SMD transistor which they have already used to good effect? Is there any kind soul who could give some advice regarding the holding circuit ( re: Caveats? ). Until now all my designs have used a suitably biased Darlington and then been tweaked on the day. Have any of you gone for an active design using a CMOS OPA instead of the basic two transistor setup? I greet all advice with much merriment! Regards to all in the group, Peter J Halford
