To: Dan Van Eldren
Fr: Jed Margolin
Re: Namco Power Supply
Dt: 5/1/85


To put things into perspective I have converted the costs into dollars.
I have used the conversion that 12,740 Y = $51.00 .

				1K			5K
		          -------------   	-----------------
Switch Bracket		  120 Y  $ 0.48		  120 Y    $ 0.48

Transformer		3,000 Y  $12.00		2,800 Y	   $11.20

Switcher		5,250 Y	 $21.00		5,280 Y    $21.00

Filter			  540 Y  $ 2.16		  470 Y	   $ 1.88

Audio PCB		3,210 Y  $12.84		3,100 Y	   $12.40

Metal Base		  620 Y  $ 2.48		  620 Y	   $ 2.48
			-------  ------ 	-------    -------
		       12,740 Y	 $50.96	       12,360 Y	   $49.44	


I do not believe there is any way we can match these prices with
a unit that we design, purchase the parts for, and build.

I must raise the following questions about the Namco supply:
	
	1. Will the switching power supply operate over a range of
	102-135 VAC or must it be redesigned?

	2. Will the switching power supply operate at an installation
	ambient of 55 degrees Celsius without derating? 

	3. Both the switching power supply and the audio amplifier
	board are single-sided. In the past we have avoided the use
	of single-sided boards because the the parts have a tendency 
	to fall off due to vibration during shipping. Would that be a
	problem with this supply?

	4. Normally the remote voltage sense lines are connected at the 
	game board. Here they are jumpered together at the supply. 	
	Was this done on purpose or is this an error?

	5. System I and System II were designed to use +15 VDC and -15 VDC
	for the audio. This supply contains a 7812 and a 7912 which 
	normally produce +12 VDC and -12 VDC. Are they used in a circuit
	that raises their outputs to +15 VDC and -15 VDC or do they actually
	produce +12 VDC and -12 VDC? (System I can probably use +12VDC and
	-12VDC but Doug does not think it would be satisfactory for System II.)

	6. Is the heat sink containing the audio amplifiers and the regulators
	large enough to operate satisfactorily at an installation ambient
	of 55 degrees Celsius?

	7. Does the transformer have an acceptable temperature rise? Ours
	are Class 105 transformers with a maximum heat rise of 55 degrees 
	Celsius. This allows them to operate at a game installation 
	temperature of 38 degrees with a 12 degree rise to the inside of
	the cabinet. 

	8. How much will it cost to change the transformer to operate at
	120 VAC?

	9. In order to operate at 220 VAC and 240 VAC, either the power
	supply must be redesigned or we will have to use an auto-transformer
	which I believe would cost $14. 

	9. How much would the Namco supply REALLY cost if we were to use it?
	

Now about our supply (Power Base and Regulator/Audio III):

	1. $80 sounds a little high. My guess is that it would cost $70 if
	we bought the parts intelligently instead of scrapping the parts
	and then buying them back at a premium. Or paying a premium because
	of inadequate lead time.

	2. If the Regulator/Audio III could use two cheap trimpots for $0.20
	each instead of the Dual Audio taper pot that we pay $2.00 for, we
	could save $1.60 . (The pot wasn't supposed to cost that much; somehow
	Purchasing has managed to do it.)  

	3. If I could produce a supply that operated at only 120 VAC I could 
	reduce the transformer cost by $4.00 and the harness cost by $2.00 .


Caveat:

	At Atari there is no way to find out how much things will REALLY cost
	ahead of time. There is not even a way to find out how much things 
	have REALLY cost in the past.

	I think you should buy the power supplies from Namco and be done 
	with it. 


				Jed