Capacitor keeps blowing

Guest
I am really baffled now and need some Pro advise.

Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt
Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol.
Now being really baffled I ask about 60hz vs.50hz and everyone seems
to say nothing matters unless the circut is powered via AC direct to
the most extent.
I really think something is wrong with this power source as the item
works fine other than trying to charge the battery's with the AC
charger.

Can any give me an exact rundown on why this capacitor keeps blowing
and I cannot charge the batteries in this device.?

TIA
 
<jjbruce@gmail.com> wrote in message
news:1108653806.122753.286450@c13g2000cwb.googlegroups.com...
I am really baffled now and need some Pro advise.

Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt
Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol.
Now being really baffled I ask about 60hz vs.50hz and everyone seems
to say nothing matters unless the circut is powered via AC direct to
the most extent.
I really think something is wrong with this power source as the item
works fine other than trying to charge the battery's with the AC
charger.

Can any give me an exact rundown on why this capacitor keeps blowing
and I cannot charge the batteries in this device.?

TIA
Click to expand...
Did you observe proper polarity? Is the rectifier shorted?
 
jjbruce@gmail.com wrote:
I am really baffled now and need some Pro advise.

Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt
Click to expand...
uhmmmm, why are you putting 240VAC into a 120VAC device for ?

Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol.
Click to expand...
 
<jjbruce@gmail.com> wrote in message
news:1108653806.122753.286450@c13g2000cwb.googlegroups.com...
I am really baffled now and need some Pro advise.

Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt
Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol.
Now being really baffled I ask about 60hz vs.50hz and everyone seems
to say nothing matters unless the circut is powered via AC direct to
the most extent.
I really think something is wrong with this power source as the item
works fine other than trying to charge the battery's with the AC
charger.

Can any give me an exact rundown on why this capacitor keeps blowing
and I cannot charge the batteries in this device.?

TIA
Click to expand...
Sorry, What value is the capacitor you are using? IS the Voltage rating high
enough?
Also check you diodes, are they shorted?
Is it in the right way?
Best of luck
Allan
 
On Fri, 18 Feb 2005 06:55:26 +1100, MC <MC@nonexistant.place> wrote:

jjbruce@gmail.com wrote:
I am really baffled now and need some Pro advise.

Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt

uhmmmm, why are you putting 240VAC into a 120VAC device for ?
Click to expand...
ummmmm - who said (s)he did?

Check the headers before assuming the poster is in aus.

Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol.
Click to expand...
 
Hi, thanks for the input...so far.
For refference this Item is a Sprectrum Analizer or Signal Meter.
@Lord Garth..I put the capacitor in the right way,as for rectifier I
don't understand, I gather you mean Power Supply? in which case it
appears to be right.

@ Allen..The capacitor is an Electrolite 10uF 35V so all appears to be
correct.I have no idea about the diodes.It was most certainly put in
the correct way.The Item was working fine untill I plugged it in
apparently.

I missed a post here on google groups...@MC..I would also like to know
why a 120VAC device plugs straight into 240VAC,which is my only current
conclusion as to why this capacitor keeps blowing...can someone explain
to me what issue I will have when 120VAC is plugged into 240VAC?
I plugged this power supply/charger straight into 240VAC without taking
any notice,I did so again after replacing the capacitor that
blew...then relised somthing was terribly wrong somewhere...
I am in Australia.

TIA
 
<jjbruce@gmail.com>...

Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt
Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol.
Click to expand...

** Describe the "charger".

Was it one that came with a piece of gear ?

Is it light as a feather or heavy like most older ones ??

Is it a plug pack or a box with an AC power lead ?

If a plug pack - has it got angled pins that fit an Aussie outlet ?

If a box with power lead - how are you connecting it to the 240v supply ?


BTW Nothing in your story makes any sense so far.





............. Phil
 
His email address does suggest he is Australian..


"budgie" <me@privacy.net> wrote in message
news:r1oa11hbscfg35jb1eu6ujglmbsg8q3l5k@4ax.com...
On Fri, 18 Feb 2005 06:55:26 +1100, MC <MC@nonexistant.place> wrote:

jjbruce@gmail.com wrote:
I am really baffled now and need some Pro advise.

Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt

uhmmmm, why are you putting 240VAC into a 120VAC device for ?

ummmmm - who said (s)he did?

Check the headers before assuming the poster is in aus.

Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol.
Click to expand...
 
On 17 Feb 2005 23:37:48 -0800, jjbruce@gmail.com wrote:

Hi, thanks for the input...so far.
For refference this Item is a Sprectrum Analizer or Signal Meter.
@Lord Garth..I put the capacitor in the right way,as for rectifier I
don't understand, I gather you mean Power Supply? in which case it
appears to be right.

@ Allen..The capacitor is an Electrolite 10uF 35V so all appears to be
correct.I have no idea about the diodes.It was most certainly put in
the correct way.The Item was working fine untill I plugged it in
apparently.

I missed a post here on google groups...@MC..I would also like to know
why a 120VAC device plugs straight into 240VAC,which is my only current
conclusion as to why this capacitor keeps blowing...can someone explain
to me what issue I will have when 120VAC is plugged into 240VAC?
I plugged this power supply/charger straight into 240VAC without taking
any notice,I did so again after replacing the capacitor that
blew...then relised somthing was terribly wrong somewhere...
I am in Australia.

TIA
Click to expand...
When you plug a 120v ac device into 240v you are doubling the input
voltage - and into a resistive load at least - you are quadrupling the
actual power consumption the load will draw. In almost all cases the
load cannot dissipate this power other than by heating up - ultimately
the load will burn, explode, or heat up to a point where the some
point in the circuit melts, (preferably a fuse) physically opening
the circuit and ending the process.

(switchmode power supplies may be designed to cope with this
overvoltage - but they are a different subject altogether)

In the case of an eletrolytic capacitor - the internal "cap juice"
will boil, and its internal pressure will rise as it boils.
Ultimately the capacitor's housing will be unable to withstand the
pressure and will rupture at its weakest point, (usually the plastic
base/metal seal - or the top) usually with a loud bang, and
discharging the contents as an added bonus.



Exploding electrolytic caps can be extremely dangerous, as the casing
often flies off with substantial force. I wouldnt like to have this
hit me - especially somewhere like in the eye.

some older caps are also likely to contain very dangerous chemicals
such as PCB's as well.
 
"budgie" <me@privacy.net> wrote

uhmmmm, why are you putting 240VAC into a 120VAC device for ?
Click to expand...
ummmmm - who said (s)he did?

Check the headers before assuming the poster is in aus.



******** ??????????????????? What is this all about then?


"I would also like to know
why a 120VAC device plugs straight into 240VAC,which is my only current
conclusion as to why this capacitor keeps blowing...can someone explain
to me what issue I will have when 120VAC is plugged into 240VAC?
I plugged this power supply/charger straight into 240VAC without taking
any notice,I did so again after replacing the capacitor that
blew...then relised somthing was terribly wrong somewhere...
I am in Australia.


Brian Goldsmith.
 
"budgie" <me@privacy.net> wrote in message
news:r1oa11hbscfg35jb1eu6ujglmbsg8q3l5k@4ax.com...
On Fri, 18 Feb 2005 06:55:26 +1100, MC <MC@nonexistant.place> wrote:

jjbruce@gmail.com wrote:
I am really baffled now and need some Pro advise.

Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt

uhmmmm, why are you putting 240VAC into a 120VAC device for ?

ummmmm - who said (s)he did?

Check the headers before assuming the poster is in aus.
Click to expand...
Budgie,

Quoted from original post is the following:

"Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt
Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol."

As you can see it DOES say Input 120Vac - assuming he is in aus (why else
post to aus.electronics only) the he seems that he may have hooked a 120Vac
device to 240Vac. This would explain why two capactitors had short but
merry lives, and its possible that when they failed they may have damaged
the rectifier circuitry (particularly as the charger is rated for 100mA and
probably drew lots more than this when blowing up the capacitors).

On the plus side, even if the power supply is Wallaby Ted's brother
(ROO-TED) he should be able to find a 240Vac/24Vdc AC adapter with a 100mA
rating fairly easily.

Ciao



Kevin



Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol.
Click to expand...
 
It was the one that came with the gear and Brand : POWER TRAN Model:m
9391
It is heavy and is a plug pack,and has pins that fit all Australian
standard 240v outlets.
One the rear of the plug pack it has PRI: 240V~50hz 12VA SEC:24V DC
500mA(Looks like this is exactly what plug pack it is) but on the front
it has the gear manufacture sticker(could have just been stuck on)
INPUT: 120VAC 60hz 4W OUTPUT:24VDC 100mA

On the gear its self it has 24VDC 60mA just below where the Charger is
plugged into the unit for charging...

..It looks like I have a FAKE charger? 500mA is too much?
 
<jjbruce@gmail.com
It was the one that came with the gear and Brand : POWER TRAN Model:m
9391
It is heavy and is a plug pack,and has pins that fit all Australian
standard 240v outlets.
One the rear of the plug pack it has PRI: 240V~50hz 12VA SEC:24V DC
500mA(Looks like this is exactly what plug pack it is) but on the front
it has the gear manufacture sticker(could have just been stuck on)
INPUT: 120VAC 60hz 4W OUTPUT:24VDC 100mA

On the gear its self it has 24VDC 60mA just below where the Charger is
plugged into the unit for charging...

.It looks like I have a FAKE charger? 500mA is too much?
Click to expand...

** OK - now the mystery is partly explained.

The remaining question is do you have a 24 volt "DC power supply " or a 24
volt battery charger. If the latter, then there will likely be no filter
cap inside the adaptor and your DC voltage measurement represents the
average value of full wave rectified AC. To convert to peak value, multiply
by 1.57.

So your 32.7 volts becomes 51 .3 volts peak.

A cap of 63 volts DC rating is needed to survive that peak value.


BTW

Why add the 10 uF cap at all ???????






................ Phil
 
"GM"
Phil Allison wrote:


** Describe the "charger".

Was it one that came with a piece of gear ?

Is it light as a feather or heavy like most older ones ??

Is it a plug pack or a box with an AC power lead ?

If a plug pack - has it got angled pins that fit an Aussie outlet ?

If a box with power lead - how are you connecting it to the 240v
supply ?


BTW Nothing in your story makes any sense so far.



I'll say - how the hell would he interpret the results from a Sprectrum
Analizer(sic) if the OP can't even work out a simple Power supply !!
Click to expand...

** Plenty of dudes with PhDs that fall into that same catagory.



BTW

I suspect his portable device might be for audio - ie it's an RTA.





............. Phil
 
lol..@GM http://www.ibiblio.org/obp/electricCircuits/ I will read this
book one day,have been tring to find time for the last two
years..........

Phil I think I have come to a solution thanks to your input .

I happened to have what appears to be a AC/DC adapter made by Danar
Electronics in Sydney rated at OUTPUT:24VDC 160mA,I split it and it
seems to have a filter cap(1000uF 35V??? is this a filter
CAP????),could not split the original as it has silly tamper screws.

I put another 10uF 35V Cap in the gear hooked the Danar power supply
and it all works,however for how long I do not know yet....It has been
charging for about 7 minutes as I type,upon unplugging and running via
battery made it reads GOOD on the dial indicator.

I don't know why the 10uF is there,it just kept blowing so I put
another there ....lol.

Good guess...the portable device is a Channel Master Signal Level Meter
1006IFD
http://www.abet-satellite-dish.com/accessories/signal_meters/CM1006IFD.asp

Just an expensive version of the $20 Satellite Finders you find every
where..

Thanks for all your input.
 
On Fri, 18 Feb 2005 08:18:18 GMT, "Brian Goldsmith"
<brian.goldsmith@nospam.echo1.com.au> wrote:

"budgie" <me@privacy.net> wrote

uhmmmm, why are you putting 240VAC into a 120VAC device for ?

ummmmm - who said (s)he did?

Check the headers before assuming the poster is in aus.



******** ??????????????????? What is this all about then?


"I would also like to know
why a 120VAC device plugs straight into 240VAC,which is my only current
conclusion as to why this capacitor keeps blowing...can someone explain
to me what issue I will have when 120VAC is plugged into 240VAC?
I plugged this power supply/charger straight into 240VAC without taking
any notice,I did so again after replacing the capacitor that
blew...then relised somthing was terribly wrong somewhere...
I am in Australia.
Click to expand...
So he is. Big deal, he could equally have been in the US of A where three out
of every four pooter users think newsgroups starting with "aus" refer to Austin
Texas.

Just because *we* are in Oz doesn't mean every poster is.

And if the above had been included in the original post, it would have been
blatantly obvious even to blind freddy what the problem was.
 
On Fri, 18 Feb 2005 08:34:53 GMT, "Kevin Ettery" <kpettery@dcsi.net.au> wrote:

"budgie" <me@privacy.net> wrote in message
news:r1oa11hbscfg35jb1eu6ujglmbsg8q3l5k@4ax.com...
On Fri, 18 Feb 2005 06:55:26 +1100, MC <MC@nonexistant.place> wrote:

jjbruce@gmail.com wrote:
I am really baffled now and need some Pro advise.

Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt

uhmmmm, why are you putting 240VAC into a 120VAC device for ?

ummmmm - who said (s)he did?

Check the headers before assuming the poster is in aus.

Budgie,

Quoted from original post is the following:

"Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt
Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol."
Click to expand...
I've got a "12V DC 300mA" wallwart here which puts out 16V on o/c, very similar
to his figures.

As you can see it DOES say Input 120Vac - assuming he is in aus (why else
post to aus.electronics only) the he seems that he may have hooked a 120Vac
device to 240Vac. This would explain why two capactitors had short but
merry lives, and its possible that when they failed they may have damaged
the rectifier circuitry (particularly as the charger is rated for 100mA and
probably drew lots more than this when blowing up the capacitors).
Click to expand...
Se my reply to BG re *foreigners* posting to this and other "aus." hierarchy
ng's.


On the plus side, even if the power supply is Wallaby Ted's brother
(ROO-TED) he should be able to find a 240Vac/24Vdc AC adapter with a 100mA
rating fairly easily.
Click to expand...
Pretty cheap too.
 
jjbruce@gmail.com wrote:
I missed a post here on google groups...@MC..I would also like to know
why a 120VAC device plugs straight into 240VAC,which is my only current
conclusion as to why this capacitor keeps blowing...can someone explain
to me what issue I will have when 120VAC is plugged into 240VAC?
I plugged this power supply/charger straight into 240VAC without taking
any notice,I did so again after replacing the capacitor that
blew...then relised somthing was terribly wrong somewhere...
I am in Australia.

TIA

LOL.
Click to expand...
I'm no expert that might be your problem. Yes.
 
Phil Allison wrote:
jjbruce@gmail.com>...


Plugged the AC charger in and it blew the capacitor sky high after
10sec. of power.
Got a new capacitor and blew that even higher into the sky after 10sec
of power.
Looked at the charger AC adapter and it says Input:120VAC 60hz 4watt
Output: 24VDC 100mA,hooked it to mulitmeter and it says 32.7 V ok , 29
V would have been nice to see,,lol.



** Describe the "charger".

Was it one that came with a piece of gear ?

Is it light as a feather or heavy like most older ones ??

Is it a plug pack or a box with an AC power lead ?

If a plug pack - has it got angled pins that fit an Aussie outlet ?

If a box with power lead - how are you connecting it to the 240v supply ?


BTW Nothing in your story makes any sense so far.





............ Phil


I'll say - how the hell would he interpret the results from a Sprectrum
Click to expand...
Analizer(sic) if the OP can't even work out a simple Power supply !!
 
"budgie" <me@privacy.net> wrote in message
news:gplb11ls9duvqj4cjm0deeo89itukivouj@4ax.com...
On Fri, 18 Feb 2005 08:18:18 GMT, "Brian Goldsmith"
[SNIP]
Click to expand...

So he is. Big deal, he could equally have been in the US of A where three
out
of every four pooter users think newsgroups starting with "aus" refer to
Austin
Texas.

Just because *we* are in Oz doesn't mean every poster is.

And if the above had been included in the original post, it would have
been
blatantly obvious even to blind freddy what the problem was.
Click to expand...
Apparently not to the OP but who seems to have trouble understanding why a
device clearly marked "120VAC" shouldn't plug into "240VAC". Didn't they
pass a law about such people using electricity????????????????
 
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