Re: Amplifone +/- 24v regulation

Hi all,

I'll have some feedback about this experiment shortly. I haven't made
enough time to finish the conversion yet, but I think I'll have it done
soon. I decided to connectorize the whole thing, and mount both the
regulators and the transistors onto new heatsinks, with those 0.1" molex
connectors joining the whole mix.

I ran out of 0.1" pins, so that has stopped me momentarily. The local
guys here at Active Electronics don't even know what they are, never
mind whether or not they have them in stock. Sigh.

Joel-

Zonn wrote:
>
> On Fri, 10 Jul 1998 09:01:00 -0400, Joel Rosenzweig <joel-r@an.hp.com> wrote:
>
> >Zonn,
> >
> >I wanted to thank you for taking the time to respond so thoroughly to my
> >question regarding the Amplifone current regulation. That was really
> >awesome to see a schematic accompany the reply!!!
> >
> >If I may be so bold .. what does the complementary circuit look like for
> >the 7924/2N3716? I have this vision of swapping some combination of the
> >transistor leads incorrectly. As you can tell, analog circuit design is
> >not my area of expertise. :-) I mean, umm, given that this email is
> >getting archived, shouldn't we have the circuit drawn out, just for the
> >record? You know, just in case some other misguided soul tries to get
> >rock solid performance out of his Amplifone this weekend? Yeah ..
> >that's it.
>
> The 7924 looks nearly the same:
>
> +------------+--- ----------+
> | ^ E C / |
> | \ / 2N3716 |
> | 6 ohm 1/2 watt ----- |
> | +--/\/\/---+ |B |
> | | | | ------- |
> -unreg ---+--+---X X----+-----+----|7924 |---+---- -24v reg
> ^ in ------- out
> Cut trace here |gnd
> |
> ---
> -
>
> as opposed to the 7824:
>
> +------------+--- ----------+
> | \ E C / |
> | V / 2N3792 |
> | 6 ohm 1/2 watt ----- |
> | +--/\/\/---+ |B |
> | | | | ------- |
> +unreg ---+--+---X X----+-----+----|7824 |---+---- +24v reg
> ^ in ------- out
> Cut trace here |gnd
> |
> ---
> -
>
> I've marked the Emitter, Base and Collector of the transistor, and the IN, GND
> and OUT of the regulators.
>
> The thing you must be careful about is the pinouts of the regulators. The IN,
> OUT, and GND pins are numbered differently between the 7824 and the 7924. (Just
> from memory I believe the OUT pin is the same on both regulators and the IN and
> GND is swapped between them. Be careful and make sure to look this up in a data
> book or something.)
>
> Use insulating washers when mounting the transistors to a heatsink (you'll have
> to find a heatsink), check for shorts, blah, blah, blah...
>
> This circuit worked fine on a WG monitor, but it meant a lot of rewiring from
> the original LV regulator. Anders design is so much easier to install, that the
> LV2000 is definitely the way to go on a WG.
>
> As far as the Amplifone goes, the above circuit is a very easy one to implement,
> without the need for a PC board.
>
> It'll be interesting to see how the beefed up regulators effect the Star Wars
> explosion sequence!
>
> -Zonn
>
> <><><><><><><><><><><><><><><><><><><><><><><><><><><><
>
> ------ ___ Member of A.A.C.S.:
> |---- | ( ) Association for Artistically
> / / ( () ) Challenged Signatures
> / / //\\ // (__)
> / ---/ // \\ //\\ // zonn @ zonn . com
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Received on Thu Jul 16 11:31:12 1998