Re: P-ROC and kits

On Feb 24, 7:55 am, GaryTheNoTrashCougar <djsc...@xxxxxxxxx> wrote:
On Feb 23, 5:20 pm, TheKorn <TheK...@xxxxxxxxxxx> wrote:









GaryTheNoTrashCougar <djsc...@xxxxxxxxx> wrote in news:e2e24e8b-b99f-
4941-b3eb-7b782fa1a...@xxxxxxxxxxxxxxxxxxxxxxxxxxx:

In my opinion, using a car amp and ATX power supply is overkill.  We
will only really need a small amplifier board that does not have any
special features or volume control on it.  I found some really nice
ones that aren't that unreasonable in price.  See link below.

http://ampslab.com/bi70mk2.htm

Why would you buy that?  You're throwing money out the window, because
you're not using off the shelf components (read:  CHEAP!) and instead
going with a special-purpose (read:  EXPENSIVE!) devices.

Car amps can be had DIRT cheap all day long:

http://cgi.ebay.com/JVC-KS-AX3002-2-CH-Car-Amplifier-65-watts-RMS-x-
2-/140504011542?pt=Car_Amplifiers&hash=item20b6b11316

And a power supply to run it can also be had DIRT cheap:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817148043
&cm_re=atx_power_supply-_-17-148-043-_-Product

...and that's not even on sale!  If the power supply fries itself, *who
cares*, throw it out and buy a new one.  

By comparison, you have to *find* a transformer that will output 30VAC
for that board you linked, it has 1/3rd the power, AND it costs
significantly more *without* the transformer.  (The transformer built
into games wouldn't be up to the task, since every time a solenoid would
fire you'd be starving the amp for power.)

Given all that, why *wouldn't* you use a car amp?  It seems like a slam
dunk (cheap, multiple suppliers, if it breaks do a forklift upgrade) to
me.

--
Have a home video that's trapped on your camera?  Want to share it on the
web or on DVD?

http://www.webwidevideo.com/

Hey Korn,
I do agree that kits would be more expensive.  Did you use the car amp
setup for your Bride of Pinbot?  With my recommendation, I figured you
could spend $110 and just tap the power off the transformer.  But I
read wrong on the voltage requirement.  It would be a pain to get 30v
off the transformer without a regulator circuit and would require an
external power supply.  I have just had bad experiences in my day with
off the shelf cheapo car amps.  I would spend a little extra money to
get something I knew had a smaller chance of failing on me.  Just a
personal preference.  :)

If you want to talk cheap...  Just buy a set of off the shelf computer
speakers and harvest the amp out of it.  I actually did this in a MAME
machine once and it still works 10 years later.  I didn't expect that.

--Scott

Here is another cheap alternative that can run on 8 to 22vdc.

http://www.sparkfun.com/products/9612

--Scott
.

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