Question:

I am looking for a fairly powerful and cheap DC amplifier for a
project i am working on : DC to say 1-5khz response, maybe 10-50
watts. I was wondering if any of these car stereos sub amps can be
modified ( like getting rid of output capacitors ) to work this way. I
understand DC is basically bad for speakers, but I was wondering since
these units are optimized for "near" dc response, the circutry may be
adaptable for my application. If anyone can point be to a cheap source
for these I will be eternally grateful, I will name my next pet after
you or something.

If someone has a convenient link to a few of the schematics of these
sub-amps I will look for myself and try and figure it out.... maybe
build one...

Thanks in advace,

Bill

Some amplifiers are capable of DC output, you will have to do your own
research to find one.

I'm curious what your application is. Would you be willing to build one
yourself? If so I can certainly help you out with a simple and inexpensive
design to achieve 50 watts output from DC to 5KHz.


wrote in message
om...
Question:

I am looking for a fairly powerful and cheap DC amplifier for a
project i am working on : DC to say 1-5khz response, maybe 10-50
watts. I was wondering if any of these car stereos sub amps can be
modified ( like getting rid of output capacitors ) to work this way. I
understand DC is basically bad for speakers, but I was wondering since
these units are optimized for "near" dc response, the circutry may be
adaptable for my application. If anyone can point be to a cheap source
for these I will be eternally grateful, I will name my next pet after
you or something.

If someone has a convenient link to a few of the schematics of these
sub-amps I will look for myself and try and figure it out.... maybe
build one...

Thanks in advace,

Bill

Hey Kevin,

Thanks,
I may take you up on that, for testing I plan to use a Kepco BOP.

This is a pet project of mine.

I need a custom small linear voice coil transducer and driver
circutry... a few other things...simple filters.
I have quite a bit of experimenting yet to do to determine what power
and bandwidth I need. I have spent a bunch of time and money getting
my little lab together... I have a lot of nice toys including a Taig
table-top cnc machine which I am leaning how to use. I have some basic
electronic troubleshooting knowledge and experience, but I can't say I
have really built much from scratch.

Where are you at?
I am currently in NY on Long Island.

I am hoping to find that I can get away with less than 10 watts (0-10v
1 amp), a millisec system rise time using basically a single
monolithic device... there are audio amps like that, I haven't looked
around all that much for dc amps, but I am hopeful.

Take care,
Bill

BTW I don't think I will be posting through google any more, I have
been getting a slew of virus laden emails lately. feel free to email
me privately.



"Kevin Murray" wrote in message et.cable.rogers.com...
Some amplifiers are capable of DC output, you will have to do your own
research to find one.

I'm curious what your application is. Would you be willing to build one
yourself? If so I can certainly help you out with a simple and inexpensive
design to achieve 50 watts output from DC to 5KHz.

Bill,

Nice power supply. Which model are you using? If you are looking for a
reversible power supply then I would point you towards the National
Semiconductor LM3886 "Overture" amplifier IC. It would make a nice, simple,
reversible drive for a small DC motor or the like. Audio amplifiers are
routinely required to drive reactive loads so load inductance shouldn't be a
problem if that is your application. Are you hoping to build a CNC motor
drive? Will you be using the digital control function (GPIB) of your Kepco
during testing? I must admit I'm very curious now Your requirement of 1
millisecond rise time to 10 volts is very reasonable. Most audio amplifiers
are capable of at least 11 volts per microsecond.

The LM3886 requires a +/- power supply and a few external components to get
it up and running. I have art work for a small PCB design if you are
ambitious enough to build a board from scratch. I also have the datasheet
for the IC, both of which I can send you if you like.

I live in Ottawa, Canada and I work in the high-tech industry. I use to work
for Telemus Inc (a Northrop Grumman company) building RADAR jammers but
sadly I'm unemployed at the moment. Currently I scratch a living with temp
positions and console myself with home projects like huge audio amplifiers.
I use a PC soundcard for a sampling oscilloscope in my workshop at home. It
has two channels (L&R) and can sample at up to 48KHz. Newer sound cards will
sample at up to 96KHz! The input maxes out at 3volts so I use a resistive
scaling network to measure higher voltages. I used a zener diode to protect
the soundcard from my moments of idiocy. My future plans involve an input
circuit to allow balanced input, overvoltage protection, isolation, and
scalable input.

When posting to any forum on the internet these days it's wise to insert a
"removethis" or such qualifier into your email address. New generation
viruses cruise the newsgroups to harvest new email addresses to try to send
copies of themselves to. Too many unemployed programmers angry at the world
I suppose...

Warm regards,

Kevin Murray



wrote in message
om...
Hey Kevin,

Thanks,
I may take you up on that, for testing I plan to use a Kepco BOP.

This is a pet project of mine.

I need a custom small linear voice coil transducer and driver
circutry... a few other things...simple filters.
I have quite a bit of experimenting yet to do to determine what power
and bandwidth I need. I have spent a bunch of time and money getting
my little lab together... I have a lot of nice toys including a Taig
table-top cnc machine which I am leaning how to use. I have some basic
electronic troubleshooting knowledge and experience, but I can't say I
have really built much from scratch.

Where are you at?
I am currently in NY on Long Island.

I am hoping to find that I can get away with less than 10 watts (0-10v
1 amp), a millisec system rise time using basically a single
monolithic device... there are audio amps like that, I haven't looked
around all that much for dc amps, but I am hopeful.

Take care,
Bill

BTW I don't think I will be posting through google any more, I have
been getting a slew of virus laden emails lately. feel free to email
me privately.



"Kevin Murray" wrote in message
et.cable.rogers.com...
Some amplifiers are capable of DC output, you will have to do your own
research to find one.

I'm curious what your application is. Would you be willing to build one
yourself? If so I can certainly help you out with a simple and
inexpensive
design to achieve 50 watts output from DC to 5KHz.