sci.electronics.repair@googlegroups.com

Today's topics:

* Ampeg BA600 - 115 bass amp combo, 6 months old, ROHS - 3 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/bc6178fc14fcf982?hl=en
* Blew another damn transformer on my Trane XB80 - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/f883cd09a3a0b791?hl=en
* minidisc player shows track but won't play tracks - 7 messages, 6 authors
http://groups.google.com/group/sci.electronics.repair/t/305742f0844c5c34?hl=en
* Uniselector mini project. - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/b7082851ed958781?hl=en
* DATING ROMANCE -DATING CHAT ROOMS -FREE ONLINE DATING -JOIN NOW - 1 messages,
1 author
http://groups.google.com/group/sci.electronics.repair/t/e2039a6d99ca163d?hl=en

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TOPIC: Ampeg BA600 - 115 bass amp combo, 6 months old, ROHS
http://groups.google.com/group/sci.electronics.repair/t/bc6178fc14fcf982?hl=en
==============================================================================

== 1 of 3 ==
Date: Sat, Apr 16 2011 12:48 am
From: "N_Cook"

Downloaded the datasheet and that IRS is for pwm/D class operation. Input
,pin3, goes back via Q9 to 74C04 buffer so digital.
That large L , in a 53x53x24mm case is connected between the common points
of both FET pairs and across the speaker (with an ohm or so somewhere not
ascertained). That L1 measures 4K ohms , inductance not possible on LCR
meter as a yellow block HV polyprop? cap , label obscured by L1, is also
across it but measures 1.15uF apparently on LCR meter.

Speaker lead has a 4 pole connector for disassembly , 2 poles per wire, but
same size connector on the pcb only 1 pole each. Worse than that the commons
traces going to L1 are 3mm wide with solder run thickening for the current
but the 2 output traces going to the speaker are 1.5 mm wide and plain
tinned. So assuming 300 watt for a second into 4 ohm then about 9 amps.
From the Enumber in ul.com, it is 1 oz board and using
http://www.pcbco.com.au/tracecalc.html
for 60 mil track and 9 amps for plain copper then 100 deg C rise , don't
know how much the tinning coat would change things , say an unlikely
doubling to 2 oz in effect, then 32 deg C rise , unacceptable ?

== 2 of 3 ==
Date: Sat, Apr 16 2011 9:02 am
From: "N_Cook"

Can you have the bridge of a bridge tied D-Class filter of form
insted of

--L--Sp--L--

as single L and speaker and C in parallel

|-----Sp-----|
----|------L-----|------
|-------C----|

L is inductor ,Sp speaker,C capacitor

== 3 of 3 ==
Date: Sat, Apr 16 2011 10:26 am
From: "N_Cook"

I'd forgotten the double wound toroid inductor of 360uH in series either
side of the speaker.
What sort of value of inducance for L1 and its wire gauge/current carrying
requirement for 300 to 600W use? C may be about 1uF

==============================================================================
TOPIC: Blew another damn transformer on my Trane XB80
http://groups.google.com/group/sci.electronics.repair/t/f883cd09a3a0b791?hl=en
==============================================================================

== 1 of 2 ==
Date: Sat, Apr 16 2011 10:04 am
From: John Robertson

Tony Miklos wrote:
> OK ;-)

An example of excessive trimming...

John :-#)#
--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

== 2 of 2 ==
Date: Sat, Apr 16 2011 10:58 am
From: "Stormin Mormon"

Top posted, too!

--
Christopher A. Young
Learn more about Jesus
www.lds.org
.

"John Robertson" <spam@flippers.com> wrote in message
news:Q5WdnWnG5pyLUTTQnZ2dnUVZ_ridnZ2d@giganews.com...
Tony Miklos wrote:
> OK ;-)

An example of excessive trimming...

John :-#)#
--
(Please post followups or tech enquiries to the
newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T
3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video
Games)
www.flippers.com
"Old pinballers never die, they just flip out."

==============================================================================
TOPIC: minidisc player shows track but won't play tracks
http://groups.google.com/group/sci.electronics.repair/t/305742f0844c5c34?hl=en
==============================================================================

== 1 of 7 ==
Date: Sat, Apr 16 2011 10:10 am
From: willywainwright

hello, I have a number of sony minidisc players that suddenly won't
play the track for no apparent reason. I've tried batteries and plug
in power with no difference. Powers up fine, shows spinning icon in
window, track number shows but I can't get the units to play the disc.
I've tried it in all positions, even upside down and sideways but
still no playing of disc
any ideas?
willy

== 2 of 7 ==
Date: Sat, Apr 16 2011 10:30 am
From: "N_Cook"

willywainwright <ww10@mac.com> wrote in message
news:e6dab674-d751-49d8-b0c6-30237220af6b@j9g2000prj.googlegroups.com...
> hello, I have a number of sony minidisc players that suddenly won't
> play the track for no apparent reason. I've tried batteries and plug
> in power with no difference. Powers up fine, shows spinning icon in
> window, track number shows but I can't get the units to play the disc.
> I've tried it in all positions, even upside down and sideways but
> still no playing of disc
> any ideas?
> willy

How many different players?
Laid the discs near a powerful louspeaker?
Tried on someone elses player ?

== 3 of 7 ==
Date: Sat, Apr 16 2011 10:30 am
From: "William Sommerwerck"

More than one? That suggests a bad disk, not a bad player.

== 4 of 7 ==
Date: Sat, Apr 16 2011 11:30 am
From: Meat Plow

On Sat, 16 Apr 2011 10:10:06 -0700, willywainwright wrote:

> hello, I have a number of sony minidisc players that suddenly won't play
> the track for no apparent reason. I've tried batteries and plug in power
> with no difference. Powers up fine, shows spinning icon in window, track
> number shows but I can't get the units to play the disc. I've tried it
> in all positions, even upside down and sideways but still no playing of
> disc
> any ideas?
> willy

So let me see if I understand you. You have multiple players that won't
play one track on one disc? Or you have one disc that won't play any
tracks on multiple players? Or you have multiple discs that won't play on
multiple players? Which is it?

--
Live Fast Die Young, Leave A Pretty Corpse

== 5 of 7 ==
Date: Sat, Apr 16 2011 12:23 pm
From: a7yvm109gf5d1@netzero.com

On Apr 16, 12:10 pm, willywainwright <w...@mac.com> wrote:
> hello, I have a number of sony minidisc players that suddenly won't
> play the track for no apparent reason. I've tried batteries and plug
> in power with no difference. Powers up fine, shows spinning icon in
> window, track number shows but I can't get the units to play the disc.
> I've tried it in all positions, even upside down and sideways but
> still no playing of disc
> any ideas?
> willy

1) Try lens cleaner disc.
2) Now toss the whole shebang in the garbage
3) Get a free cell phone, even they'll come with a MP3 player.

Minidisc is over. It's dead, finished, kaput. And I'm speaking as
someone who bought a MZ-1 when they first came out.

== 6 of 7 ==
Date: Sat, Apr 16 2011 12:34 pm
From: Meat Plow

On Sat, 16 Apr 2011 12:23:19 -0700, a7yvm109gf5d1 wrote:

> On Apr 16, 12:10 pm, willywainwright <w...@mac.com> wrote:
>> hello, I have a number of sony minidisc players that suddenly won't
>> play the track for no apparent reason. I've tried batteries and plug in
>> power with no difference. Powers up fine, shows spinning icon in
>> window, track number shows but I can't get the units to play the disc.
>> I've tried it in all positions, even upside down and sideways but still
>> no playing of disc
>> any ideas?
>> willy
>
> 1) Try lens cleaner disc.
> 2) Now toss the whole shebang in the garbage 3) Get a free cell phone,
> even they'll come with a MP3 player.
>
> Minidisc is over. It's dead, finished, kaput. And I'm speaking as
> someone who bought a MZ-1 when they first came out.

I own a Sharp S60 and a Sony NetMD. Both record wonderfully with a stereo
condenser mic, the Sony will load songs from a PC in about 4 minutes.
Also has an FM tuner. Minidisc isn't dead for me. I also own 32 gig Ipod
Touch. I use all three frequently.

--
Live Fast Die Young, Leave A Pretty Corpse

== 7 of 7 ==
Date: Sat, Apr 16 2011 6:21 pm
From: "Arfa Daily"

"Meat Plow" <mhywattt@yahoo.com> wrote in message
news:pan.2011.04.16.19.33.57@lmao.lol...
> On Sat, 16 Apr 2011 12:23:19 -0700, a7yvm109gf5d1 wrote:
>
>> On Apr 16, 12:10 pm, willywainwright <w...@mac.com> wrote:
>>> hello, I have a number of sony minidisc players that suddenly won't
>>> play the track for no apparent reason. I've tried batteries and plug in
>>> power with no difference. Powers up fine, shows spinning icon in
>>> window, track number shows but I can't get the units to play the disc.
>>> I've tried it in all positions, even upside down and sideways but still
>>> no playing of disc
>>> any ideas?
>>> willy
>>
>> 1) Try lens cleaner disc.
>> 2) Now toss the whole shebang in the garbage 3) Get a free cell phone,
>> even they'll come with a MP3 player.
>>
>> Minidisc is over. It's dead, finished, kaput. And I'm speaking as
>> someone who bought a MZ-1 when they first came out.
>
>
> I own a Sharp S60 and a Sony NetMD. Both record wonderfully with a stereo
> condenser mic, the Sony will load songs from a PC in about 4 minutes.
> Also has an FM tuner. Minidisc isn't dead for me. I also own 32 gig Ipod
> Touch. I use all three frequently.
>
>

Which reminds me. Presumably you got on ok dismantling the Touch a few weeks
ago ?

Arfa

==============================================================================
TOPIC: Uniselector mini project.
http://groups.google.com/group/sci.electronics.repair/t/b7082851ed958781?hl=en
==============================================================================

== 1 of 2 ==
Date: Sat, Apr 16 2011 2:50 pm
From: T i m

Hi all,

I would like to use a uniselector (got) to step to its next position
upon connection to a mains supply (through 'X' circuitry). This will
probably be at one_per_day time intervals.

Ideally said circuitry would consume as little energy itself as
possible.

What I'm actually trying to do is 'cycle' an intelligent low current
(.5A) but quite expensive charger to a range of smallish 12V lead acid
batteries. Once each battery is actually charged (probably elsewhere)
it will be kept topped up by said project applying said charger once
every Y days (where Y could be 25 as I think it's a 25 way selector).

I could use (make) a 240 ac to 50V DC PSU (assuming the uniselector
was designed to run at that) and then create a suitably long one shot
pulse on power-up (charge cap?). I could probably even just use one
mains digital time switch, energising the uniselector 'step' cct for
one minute, again via a suitable charge cap (so the coil isn't left
energised for longer than needed)?

Ideally though both the charger and the stepper sides would be power
cycled at the same time (to ensure the charger was reset). Or the
charger de-powered when the selector is pulsed (so the selector isn't
actually switching the charge current).

Ideas welcome please. ;-)

Cheers, T i m

== 2 of 2 ==
Date: Sat, Apr 16 2011 5:21 pm
From: KR

On Apr 17, 7:50 am, T i m <n...@spaced.me.uk> wrote:
> Hi all,
>
> I would like to use a uniselector (got) to step to its next position
> upon connection to a mains supply (through 'X' circuitry). This will
> probably be at one_per_day time intervals.
>
> Ideally said circuitry would consume as little energy itself as
> possible.
>
> What I'm actually trying to do is 'cycle' an intelligent low current
> (.5A) but quite expensive charger to a range of smallish 12V lead acid
> batteries. Once each battery is actually charged (probably elsewhere)
> it will be kept topped up by said project applying said charger once
> every Y days (where Y could be 25 as I think it's a 25 way selector).
>
> I could use (make) a 240 ac to 50V DC PSU (assuming the uniselector
> was designed to run at that) and then create a suitably long one shot
> pulse on power-up (charge cap?).  I could probably even just use one
> mains digital time switch, energising the uniselector 'step' cct for
> one minute, again via a suitable charge cap (so the coil isn't left
> energised for longer than needed)?
>
> Ideally though both the charger and the stepper sides would be power
> cycled at the same time (to ensure the charger was reset). Or the
> charger de-powered when the selector is pulsed (so the selector isn't
> actually switching the charge current).
>
> Ideas welcome please. ;-)
>
> Cheers, T i m

Use a DC supply to run it, and (say) 2200uf electrolytic in series.
This will hold it in for a couple of seconds upon power up. If it is
not long enough, use a larger value cap. It would be a good idea to
put a diode across the coil, with the K (stripe) to the positive to
prevent back EMF from the coil possibly damaging the capacitor over
time.

Note that this will pulse the coil once every time you turn on the
power, it will not pulse again until the power is turned off and on
again.

I have used this method in the past with relays to provide a power on
delay and it has worked well for over 10 years.

==============================================================================
TOPIC: DATING ROMANCE -DATING CHAT ROOMS -FREE ONLINE DATING -JOIN NOW
http://groups.google.com/group/sci.electronics.repair/t/e2039a6d99ca163d?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, Apr 16 2011 11:09 pm
From: devi vithya

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