Problem with electret mic-LM386 power supply.

X

xx

Guest
I'm having some difficulties figuring out why I can power my electret
condenser mic & LM386 amp with a battery, but then when I try to used 9 volt
rectified power (from a 15v power wart), it won't work. Any hints as to why
this wouldn't work?

The condenser mic and LM386 follow the standard data sheet schematics for
their use. Nothing special there.

Thanks,
Chris
 
"xx" <xx@xxxx.com> wrote in message news:bneem4$idd$1@bob.news.rcn.net...
I'm having some difficulties figuring out why I can power my electret
condenser mic & LM386 amp with a battery, but then when I try to used 9
volt
rectified power (from a 15v power wart), it won't work. Any hints as to
why
this wouldn't work?

The condenser mic and LM386 follow the standard data sheet schematics for
their use. Nothing special there.

Thanks,
Chris
Click to expand...
Look for the wall wart to exhibit truly crappy DC that has much ripple and
that sags under load.
 
Are you using a regulator as well? Have you looked insode the wall wart to
see if there is a proper size cap in there?

"xx" <xx@xxxx.com> wrote in message news:bneem4$idd$1@bob.news.rcn.net...
I'm having some difficulties figuring out why I can power my electret
condenser mic & LM386 amp with a battery, but then when I try to used 9
volt
rectified power (from a 15v power wart), it won't work. Any hints as to
why
this wouldn't work?

The condenser mic and LM386 follow the standard data sheet schematics for
their use. Nothing special there.

Thanks,
Chris
Click to expand...
 
In article <TlBmb.39$Ky2.31@newssvr22.news.prodigy.com>,
LGarth@Tantalus.net mentioned...
"xx" <xx@xxxx.com> wrote in message news:bneem4$idd$1@bob.news.rcn.net...
I'm having some difficulties figuring out why I can power my electret
condenser mic & LM386 amp with a battery, but then when I try to used 9
volt
rectified power (from a 15v power wart), it won't work. Any hints as to
why
this wouldn't work?

The condenser mic and LM386 follow the standard data sheet schematics for
their use. Nothing special there.

Thanks,
Chris

Look for the wall wart to exhibit truly crappy DC that has much ripple and
that sags under load.
Click to expand...
True, but batteries ain't all that great, either. A resistor and 1000
uF capacitor can take care of much of the progblem. But he failed to
say what "doesn't work" means. For all we know, he could be
connecting the 'power wart' up with the wrong polarity. Duh.


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.1a055c59d90b2e1098982e@news.dslextreme.com...
In article <TlBmb.39$Ky2.31@newssvr22.news.prodigy.com>,
LGarth@Tantalus.net mentioned...


Look for the wall wart to exhibit truly crappy DC that has much ripple
and
that sags under load.

True, but batteries ain't all that great, either. A resistor and 1000
uF capacitor can take care of much of the progblem. But he failed to
say what "doesn't work" means. For all we know, he could be
connecting the 'power wart' up with the wrong polarity. Duh.
Click to expand...
Very true, I'd expect such is the case as well being that the LM386 isn't
exactly "high power"!!!!

Say, will you continue with your flashlights? I was wondering what the
goal is, draining the battery completely or using only one cell or both.
Can you draw up your final design note and scan them, I'll pretty it up
for you.
 
In article <XKRmb.360$DX5.66@newssvr24.news.prodigy.com>,
LGarth@Tantalus.net mentioned...
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.1a055c59d90b2e1098982e@news.dslextreme.com...
In article <TlBmb.39$Ky2.31@newssvr22.news.prodigy.com>,
LGarth@Tantalus.net mentioned...


Look for the wall wart to exhibit truly crappy DC that has much ripple
and
that sags under load.

True, but batteries ain't all that great, either. A resistor and 1000
uF capacitor can take care of much of the progblem. But he failed to
say what "doesn't work" means. For all we know, he could be
connecting the 'power wart' up with the wrong polarity. Duh.

Very true, I'd expect such is the case as well being that the LM386 isn't
exactly "high power"!!!!

Say, will you continue with your flashlights?
Click to expand...
Um, which one? In the last few weeks I've built a couple in "Coffee
Mints" tins. They hold three 5 mm Nichias with the Radio Shack 270-
412 three AAA cell batt holder, which was so new that some stores
still had them stuck in the back in the shipping cartons. I had to
file/sand down the holder to fit into the tin. Once that was done,
three holes for the LEDs and a hole for a submini toggle switch.
Three 33 ohm resistors, one for each LED, connected to the switch.
The thing is about as compact as it can get. There's very little
unused room inside.

I was wondering what the
goal is, draining the battery completely or using only one cell or both.
Can you draw up your final design note and scan them, I'll pretty it up
for you.
Click to expand...
Picture's worth a thousand words. I'll repost the latest one in a new
thread. My goal was to make a flashlight that was conveniently sized
and used parts the average hobbyist could obtain. About the only hard
thing to get were the LEDs. Another goal was to stay away from exotic
batteries, use only AA or AAA cells which are dirt cheap. I got
(limit 5 per customer) 5 packs of four GE/Sanyo AA alkaline cells for
89 cents each. That's less than half the usual 50 cent price. The
trend of using those CR-123 lithium cells for flashlights has brought
the price down somewhat because of volume, but you still can't find
them on the usual supermarket shelves. And IMHO still too expensive
for the average worker bee.

My later Velamints tin lights had improvements that weren't in the
early ones, so it's impossible to say where the final design is. This
is a hobbyist newsgroup for DIYers, not a manufacturing ng. I would
expect each hobbyist to have his own way of doing things, with a
general idea of his final goal. I appreciate the inspiration that
others have given me and Ed Ngai, who hasn't been seen here lately. I
hope he's still pursuing his projects.

Later. I have to dig out that pic and post it to the
alt.binaries.schematics.electronic newsgroup.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.1a064fe4d14df466989840@news.dslextreme.com...
In article <XKRmb.360$DX5.66@newssvr24.news.prodigy.com>,
LGarth@Tantalus.net mentioned...

"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.1a055c59d90b2e1098982e@news.dslextreme.com...
In article <TlBmb.39$Ky2.31@newssvr22.news.prodigy.com>,
LGarth@Tantalus.net mentioned...


Look for the wall wart to exhibit truly crappy DC that has much
ripple
and
that sags under load.

True, but batteries ain't all that great, either. A resistor and 1000
uF capacitor can take care of much of the progblem. But he failed to
say what "doesn't work" means. For all we know, he could be
connecting the 'power wart' up with the wrong polarity. Duh.

Very true, I'd expect such is the case as well being that the LM386
isn't
exactly "high power"!!!!

Say, will you continue with your flashlights?

Um, which one? In the last few weeks I've built a couple in "Coffee
Mints" tins. They hold three 5 mm Nichias with the Radio Shack 270-
412 three AAA cell batt holder, which was so new that some stores
still had them stuck in the back in the shipping cartons. I had to
file/sand down the holder to fit into the tin. Once that was done,
three holes for the LEDs and a hole for a submini toggle switch.
Three 33 ohm resistors, one for each LED, connected to the switch.
The thing is about as compact as it can get. There's very little
unused room inside.

I was wondering what the
goal is, draining the battery completely or using only one cell or both.
Can you draw up your final design note and scan them, I'll pretty it up
for you.

Picture's worth a thousand words. I'll repost the latest one in a new
thread. My goal was to make a flashlight that was conveniently sized
and used parts the average hobbyist could obtain. About the only hard
thing to get were the LEDs. Another goal was to stay away from exotic
batteries, use only AA or AAA cells which are dirt cheap. I got
(limit 5 per customer) 5 packs of four GE/Sanyo AA alkaline cells for
89 cents each. That's less than half the usual 50 cent price. The
trend of using those CR-123 lithium cells for flashlights has brought
the price down somewhat because of volume, but you still can't find
them on the usual supermarket shelves. And IMHO still too expensive
for the average worker bee.

My later Velamints tin lights had improvements that weren't in the
early ones, so it's impossible to say where the final design is. This
is a hobbyist newsgroup for DIYers, not a manufacturing ng. I would
expect each hobbyist to have his own way of doing things, with a
general idea of his final goal. I appreciate the inspiration that
others have given me and Ed Ngai, who hasn't been seen here lately. I
hope he's still pursuing his projects.

Later. I have to dig out that pic and post it to the
alt.binaries.schematics.electronic newsgroup.
Click to expand...

It sounds like you gave up all electronics in that last one. I was having
a hard time following your text description of all the changes you made
to improve efficiency. I was hoping you could sketch the changes you
settled on and then I'd draw it neatly. That way anyone could follow in
your footsteps.
 
In article <wc3nb.1101$RG2.303@newssvr24.news.prodigy.com>,
LGarth@Tantalus.net mentioned...
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.1a064fe4d14df466989840@news.dslextreme.com...
In article <XKRmb.360$DX5.66@newssvr24.news.prodigy.com>,
LGarth@Tantalus.net mentioned...

"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.1a055c59d90b2e1098982e@news.dslextreme.com...
In article <TlBmb.39$Ky2.31@newssvr22.news.prodigy.com>,
LGarth@Tantalus.net mentioned...


Look for the wall wart to exhibit truly crappy DC that has much
ripple
and
that sags under load.

True, but batteries ain't all that great, either. A resistor and 1000
uF capacitor can take care of much of the progblem. But he failed to
say what "doesn't work" means. For all we know, he could be
connecting the 'power wart' up with the wrong polarity. Duh.

Very true, I'd expect such is the case as well being that the LM386
isn't
exactly "high power"!!!!

Say, will you continue with your flashlights?

Um, which one? In the last few weeks I've built a couple in "Coffee
Mints" tins. They hold three 5 mm Nichias with the Radio Shack 270-
412 three AAA cell batt holder, which was so new that some stores
still had them stuck in the back in the shipping cartons. I had to
file/sand down the holder to fit into the tin. Once that was done,
three holes for the LEDs and a hole for a submini toggle switch.
Three 33 ohm resistors, one for each LED, connected to the switch.
The thing is about as compact as it can get. There's very little
unused room inside.

I was wondering what the
goal is, draining the battery completely or using only one cell or both.
Can you draw up your final design note and scan them, I'll pretty it up
for you.

Picture's worth a thousand words. I'll repost the latest one in a new
thread. My goal was to make a flashlight that was conveniently sized
and used parts the average hobbyist could obtain. About the only hard
thing to get were the LEDs. Another goal was to stay away from exotic
batteries, use only AA or AAA cells which are dirt cheap. I got
(limit 5 per customer) 5 packs of four GE/Sanyo AA alkaline cells for
89 cents each. That's less than half the usual 50 cent price. The
trend of using those CR-123 lithium cells for flashlights has brought
the price down somewhat because of volume, but you still can't find
them on the usual supermarket shelves. And IMHO still too expensive
for the average worker bee.

My later Velamints tin lights had improvements that weren't in the
early ones, so it's impossible to say where the final design is. This
is a hobbyist newsgroup for DIYers, not a manufacturing ng. I would
expect each hobbyist to have his own way of doing things, with a
general idea of his final goal. I appreciate the inspiration that
others have given me and Ed Ngai, who hasn't been seen here lately. I
hope he's still pursuing his projects.

Later. I have to dig out that pic and post it to the
alt.binaries.schematics.electronic newsgroup.



It sounds like you gave up all electronics in that last one. I was having
a hard time following your text description of all the changes you made
to improve efficiency. I was hoping you could sketch the changes you
settled on and then I'd draw it neatly. That way anyone could follow in
your footsteps.
Click to expand...
If you want to follow in my footsteps, go out and buy a Dorcy 4 LED, 2
AA cell flashlight for $17 or less.
http://www.dorcy.com/led%20new.htm
I bought a couple and got a $3 rebate coupon too. You can't beat
those prices. I also bought some of the 1 LED, 1 AAA cell lights for
$9, and I unscrewed the head and found that the whole PC board drops
right out, so you can 'experiment' with it. ;-) I think I might
have posted a pic of that on ABSE.

That pic I posted a few days ago to ABSE (insanely bright in the
insanely expensive Pac-Tec case) gave the info, and as for changes to
part values, one problem with the circuit is that it is dependent on
the type and individual gains of the transistors you use, and the
inductor choice makes a lot of diff in the frequency. So giving
anything other than ballpark isn't going to necessarily work for the
hobbyist, since they'll have to be changed to accomodate his choices.

Like, how many people out there are going to cut the RFI suppressor
off the end of a mouse or keyboard and saw it in half with a ceramic
tile saw, like I did? Some guys used a Dremel tool with a cutoff
wheel to cut ferrite, but it's really messy, black soot all over the
place.

The Coffee Mints one didn't use anything other than the switch and
resistors, which suits the neophyte LED light builder just fine. It's
compact and simple. But it'll never be able to compete with the cheap
Dorcy LED lights; you get done with buying stuff and counting your
time building it, it's gonna cost a lot more.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
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