help please!!

Posted: 11/10/2009 8:36:21 PM
FredM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................

Joined: 12/7/2007

[i]"The quickest and easiest way is like I did: Go to the next electronic component store, buy a 7806 regulator for a few cents and replace the diode by a bridge. No additional resistors needed." - Thierry [/i]

Undoubtably the quickest and easiest solution!

Alas, availability of some regulators can cause problems.. 12V and 5V are common, but 6,8,9 are not always in stock when you need them - Certainly, for me, buying a large quantity of 317's and therebye getting quantity discount more than offsets the cost of the resistors.

Its a real pain that the pin-out for fixed regulators (78xx) is completely different to the LM317 - I sometimes lay my PCB's out to accept either - but because of the stupid incompatibility this involves links - not nice.
Posted: 11/11/2009 12:39:22 PM
djpb_designs

From: Escondido, CA

Joined: 2/6/2008

There are later series of regulators ... usually the "low-dropout" ones ... that maintain pin compatibility between the fixed and adjustable variety. But that just adds even more stuff to keep track of. (How many of us still have most of the old 4000 series CMOS and the popular TTL part numbers permanently engraved in our heads?)

Don

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