a 723regulator for ASM1 question

[David Halliday]

Also, the overall noise of the 723 is a *lot* lower than the noise of the
generic 3-leg regulators.  Better for analog, especially when you need a
good signal to noise ratio...




-> -----Original Message-----
-> From: owner-synth-diy at node12b53.a2000.nl
-> [mailto:owner-synth-diy at node12b53.a2000.nl]On Behalf Of Harry Bissell
-> Sent: Thursday, October 26, 2000 7:55 PM
-> To: danial stocks
-> Cc: alonn at random-logic.com; synth-diy at node12b53.a2000.nl
-> Subject: Re: a 723regulator for ASM1 question
->
->
-> The 723 regulator usually has a pot where the voltage can be
-> set precisely.
-> 7815 / 7915 is luck of the draw, within the regulator tolerances.
->
-> Shame on designers who rely on the supply as a precision
-> reference. That's
-> what (er....) precision references are made for.
->
-> But if absolute voltage is not critical, the 78xx /79xx are
-> usually OK.
->
-> 723 also excells as a driver for a series pass transistor,
-> so most higher
-> current
-> supplies use this chip. An oldie but a goodie.
->
-> H^) harry
->
-> danial stocks wrote:
->
-> > >Im building a 723based reg. im using the 723datasheet schematics.
-> > >its a +15 -15 0 reg.
-> > >
-> > >one of the parts is a 2n4898 which i didnt find yet.
-> > >instead iv been given a bd224c (looks like the 7815 part
-> box figure)
-> > >
-> > >is the bd224c a good replacement for the 2n4898 in the
-> case of asm1
-> > >regulator?
-> > >
-> > Hi.. I thought the 723was a simple single supp adj reg,
-> but I thnik you can
-> > ste it up for dual rail.. Generally if a trans has = or
-> higher current
-> > rating, power diss and similar gain, you can substitute
-> it..[watch out for
-> > pinout variations tho..
-> > I have on occasions simply retrofitted complex ccts like
-> this with a simple
-> > 7815/7915 combo and it works well.. [did this in a TR808,
-> havenit tried in
-> > ASR-1] but one thing to note is that there may not be any
-> real advtg to the
-> > more complex cct, just that the particular engineer didnt
-> know of the 3 term
-> > regs or they simply didnt exist at the time.. this is
-> particularly the case
-> > with really old stuff. In a newer equip maybe there is a
-> reason, I'd stick
-> > to the original cct ..
-> > Cheers,
-> > Dan
-> >
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