The Proposed Regulator/Audio III		Jed Margolin 10/5/84

The least expensive Audio/Regulator board for the Not-Budget Systemi (only) 
would be:
		+5 VDC @ 10 A
		+12 VDC @ 0.1 A
		-12 VDC @ 0.1 A
	
Two audio channels, nominally 3.7 Watts each, into 4 Ohms, using TDA 2002's 
connected to the +12 VDC output.
-------------------------------------------------------------------------------
An Audio/Regulator board that could be used with either the Not-Budget 
Systemi or the Road Runner game system would be capable of:
		
		+5 VDC @ 10 A
		+15 VDC @ 0.4 A
		-15 VDC @ 0.4 A

It would have two audio channels, nominally 10 Watts each, into 4 Ohms, using 
TDA 2030's connected to the +22 VDC output. It would cost about $2.00 more 
than one for the Not-Budget Systemi only. 
-------------------------------------------------------------------------------
This same Audio/Regulator board might be used for the Paper Boy project 
(apparently as part of some kind of backup scheme).
-------------------------------------------------------------------------------
Please send your comments to [Margolin].
Amplifier and Speaker Calculations:

For a single ended supply of voltage VS, the peak to peak voltage
will be VS minus some slop in the amplifier. Use 1 volt.
	Vp-p = VS - 1			
Therefore: Vp = (VS-1)/2	   
For Sine Wave Vrms = (VS-1)/2*0.7071

Power = Vrms*Vrms/R
      = ((VS-1)/2*0.7071)**2/R

Since POWER = I*I*R, I = SQRT(P/R)
Because it is single ended the effective current is half,
so for each channel I = SQRT(P/R)/2



	VS			 R(Speaker)	Power		   Current 	      Amplifier Type
	(V)			  (Ohms)     (/Channel)	 	1 CH / 2 CH
----------------------------------------------------------------------------------------------------
1.	10.3 (unreg)		    4		2.7 W		0.41 A  / 0.82 A	TDA 2002

2.	12 (reg)		    4		3.7 W		0.48 A	/ 0.96 A	TDA 2002

3.	15 (reg)		    4		6.1 W		0.62 A  / 1.23 A 	TDA 2002

4.	15 (reg)		    8		3.06W		0.30 A  / 0.62 A	TDA 2002


5.	18 (unreg, low line)	    4		9.2 W		0.75 A  / 1.52 A	TDA 2030
	22 (unreg, nominal)	    4		13.7 W*		0.92 A	/ 1.85 A 	TDA 2030
	26 (unreg, high line)	    4		19.5 W*		1.10 A	/ 2.20 A 	TDA 2030


6.	18 (unreg, low line)	    8		4.5 W		0.37 A	/ 0.75 A 	TDA 2030
	22 (unreg, nominal)	    8		6.9 W		0.46 A	/ 0.92 A 	TDA 2030
	26 (unreg, high line)	    8		9.7 W		0.55 A	/ 1.10 A 	TDA 2030

-------------------------------------------------------------------------------------------------------

Not-Budget Systemi current requirements for  +12 VDC and -12 VDC:

For a TI TMS-5220 + a bunch of LM324's a realistic figure is +12 VDC @ 60 ma 
and -12 VDC @ 95 ma. [The TMS-5220 requires 35 ma from -5 VDC. The +5 VDC comes
from the +5 VDC logic, not the +12 VDC. Allowing 10 ma per LM324 package * 6 
packages = 60 ma. That is 24 op-amps which should be sufficient.]

The Audio they are referring to is the Audio Output Amplifiers that this 
is to help select.

The game board requirements should be satisfied by +12 VDC @ 100 ma and 
-12 VDC @ 100 ma.

(They could probably use +12 VDC and -5 VDC or +15 VDC and -15 VDC instead).
(If they are really using LM324's, they shouldn't. They should use TL084's.)
-------------------------------------------------------------------------------
The Road Runner game requires +5 VDC @ 7.5 A, +15 VDC @ 0.4 A, and 
-15 VDC @ 0.4 A.		
-------------------------------------------------------------------------------
The audio output amplifiers cannot be powered from the +10.3 VDC because it 
is already overloaded by the +5 VDC Regulator.
-------------------------------------------------------------------------------
The 7812 is good for about 1.5 Amps.

The 7815 is also good for about 1.5 Amps.
-------------------------------------------------------------------------------
The +22 VDC output is rated at 1.5 A and the -22 VDC output is rated at 1 A. 
Since they come from the same transformer winding, the current available 
from +22 VDC is increased as the current drawn from -22 VDC is decreased.

+22 VDC actually ranges from +18 at low line to +26 VDC at high line.
-22 VDC actually ranges from -18 at low line to -26 VDC at high line.
-------------------------------------------------------------------------------
* The maximumn undistorted output level for the TDA 2030 is 10 Watts for 
4 Ohm loads and about 9 Watts for 8 Ohm loads.
-------------------------------------------------------------------------------
Possibilities for the Not-Budget Systemi:

	VS			 R(Speaker)	Power		   Current 	      Amplifier Type
	(V)			  (Ohms)     (/Channel)	 	1 CH / 2 CH
--------------------------------------------------------------------------------------------------------
2.	12 (reg)		    4		3.7 W		0.48 A	/ 0.96 A	TDA 2002
3.	15 (reg)		    4		6.1 W		0.62 A  / 1.23 A 	TDA 2002
4.	15 (reg)		    8		3.06		0.30 A  / 0.62 A	TDA 2002

5.	18 (unreg, low line)	    4		9.2 W		0.75 A  / 1.52 A	TDA 2030
	22 (unreg, nominal)	    4		13.7 W		0.92 A	/ 1.85 A 	TDA 2030
	26 (unreg, high line)	    4		19.5 W		1.10 A	/ 2.20 A 	TDA 2030

6.	18 (unreg, low line)	    8		4.5 W		0.37 A	/ 0.75 A 	TDA 2030
	22 (unreg, nominal)	    8		6.9 W		0.46 A	/ 0.92 A 	TDA 2030
	26 (unreg, high line)	    8		9.7 W		0.55 A	/ 1.10 A 	TDA 2030
--------------------------------------------------------------------------------------------------------
Possibilities for Road Runner:

4.	15 (reg)		    8		3.06		0.30 A  / 0.62 A	TDA 2002

5.	18 (unreg, low line)	    4		9.2 W		0.75 A  / 1.52 A	TDA 2030
	22 (unreg, nominal)	    4		13.7 W		0.92 A	/ 1.85 A 	TDA 2030
	26 (unreg, high line)	    4		19.5 W		1.10 A	/ 2.20 A 	TDA 2030

6.	18 (unreg, low line)	    8		4.5 W		0.37 A	/ 0.75 A 	TDA 2030
	22 (unreg, nominal)	    8		6.9 W		0.46 A	/ 0.92 A 	TDA 2030
	26 (unreg, high line)	    8		9.7 W		0.55 A	/ 1.10 A 	TDA 2030
--------------------------------------------------------------------------------------------------------
An Audio/Regulator board that could be used with either game system would 
produce:
		+5 VDC @ 10 A
		+15 VDC @ 0.4 A
		-15 VDC @ 0.4 A

	Two audio channels, nominally 10 Watts each, into 4 Ohms, using 
TDA 2030's connected to the +22 VDC output.
-------------------------------------------------------------------------------
	The least expensive configuration for the Not-Budget Systemi (only) 
would be:
		+5 VDC @ 10 A
		+12 VDC @ 0.1 A
		-12 VDC @ 0.1 A
	
	Two audio channels, nominally 3.7 Watts each, into 4 Ohms, using 
TDA 2002's connected to the +12 VDC output.

Jed,
	The JBL speakers come in 8ohms only!
	
Yes, we plan on using them. I've got most everyone convinced that they can't
live without them, (or if they do I will be very upset and won't help them
with their music!!!)

- brad -

ps    Is there any way to decrease the amount of noise in future design
of the audio amps?  We have so much noise in our systems it's irritating!

- brad-

Specifications for the Regulator/Audio III System
----------------------------------------------

+5 VDC @ 10 Amps	Regulated

+15 VDC @ 0.4 Amps	Regulated

-15 VDC @ 0.4 Amps	Regulated


6.1 VAC @ 0.5 Amps 	From Power Base (For Coin Door Lamps)

120 VAC	@ 0.9 Amps	Isolated, from Power Base (For Color Raster Monitor)

10.3 VDC 		From Power Base, use for Reset Circuit Only.
			Dropout is at 8 VDC, Holdtime is not guaranteed.
			(or specified). Beware the Jabberwock (EAROM).


(2) Audio Amplifiers:
	Each capable of delivering 6.5 Watts into 8 Ohms or 10 Watts into 
	4 Ohms (your choice). Power is for an equivalent Sine Wave input.

	The volume control is on the Regulator/Audio III Board.

	The amplifiers will deliver full output with an input of 5 Vp-p.


There will be a Self-Test switch on the Board, providing a switch closure
to ground. You must provide your own pull-up resistor.


					Jed Margolin  10/12/84


P.S. - The REGULATOR/AUDIO III is intended for use in the Not-Budget System 
as well as providing a backup for Road Runner and Paper Boy.
 
Please direct all comments to [MARGOLIN]

   Your spec looks good to me.  Thanks again for helping us out on this. I
just hope we can now manage to pull this off in the time frame we have to,
and with the parts and leadtimes we have available.

I assume that your specs aren't meant to include the supply current required
by the audio power amps, otherwise the +15v @ 400mA wouldn't cut it.

Some Asshole stole my Regulator/Audio III prototype. It was the only
one with the new audio circuitry, and was to be tested this morning.
If you are the miserable cretin who has this board, return it by 2:00 pm
today, and I may let you live.

	Thank you or else,

		Jed

If I understand your spec correctly, we will only be getting 6.8 watts
(per channel) if using the supply for stereo.  I don't think this will
be enough.  We are pretty close to the edge with what we are running now
(12 watts, I believe).  10 watts would be OK, maybe 9, but NOT 6.8

	If there is anything you can do to bring the power up to greater
than 10 watts, please, PLEASE, PLEASE, consider it.

	Rusty