D
Dave.H
Guest
I need to replace a 1.2 uF electrolytic capacitor, and the closest I
can find is 1.0 uF. Is it OK if I install this one?
can find is 1.0 uF. Is it OK if I install this one?
R
Roger Dewhurst
Guest
"Dave.H" <the1930s@googlemail.com> wrote in message
news:7eabdb5b-1f07-448b-adac-9d3ed340b633@i29g2000prf.googlegroups.com...
R
news:7eabdb5b-1f07-448b-adac-9d3ed340b633@i29g2000prf.googlegroups.com...
If you are worried stick another one in parallel to make up the total.
R
D
Dave.H
Guest
This is probably a stupid question, but what value should the second
capacitor be? The power supply is 240 volts, I can only find a 350
volt electrolytic. I've heard the electrolytics don't like too low a
voltage, would this still work?
capacitor be? The power supply is 240 volts, I can only find a 350
volt electrolytic. I've heard the electrolytics don't like too low a
voltage, would this still work?
T
Tim Wescott
Guest
On Fri, 16 Nov 2007 22:40:55 -0800, Dave.H wrote:
life.
Capacitors add in parallel, so a 1uF in parallel with a .2uF makes up
1.2uF.
--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com
Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html
1/10 the rated voltage may be a problem, but 2/3 is about right for long
life.
Capacitors add in parallel, so a 1uF in parallel with a .2uF makes up
1.2uF.
--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com
Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html
D
Dave.H
Guest
I was thinking a .2uF capacitor would be about right. Thanks for the
help, appreciate it!
D
Dave.H
Guest
Another stupid question, but would I be able to use two .01 capacitors
in parallel with the electrolytic? I can't seem to find any .2 caps.
in parallel with the electrolytic? I can't seem to find any .2 caps.
D
Daniel Mandic
Guest
Dave.H wrote:
20 times a 0.01
, yes.
2 times a 0.1, off course!
Best regards,
Daniel Mandic
Hello!
20 times a 0.01
, yes. 2 times a 0.1, off course!
Best regards,
Daniel Mandic
D
Dave.H
Guest
Sorry, I don't understand what you are saying. Please excuse myHello!
20 times a 0.01
2 times a 0.1, off course!
Best regards,
Daniel Mandic
almost non existent knowledge of elctronic circuits, I'm still
learning .
D
Dave.H
Guest
I have tested the original capacitor again, this time disconnected
from the circuit completely, and returned a more accurate reading of
1.248 uF. I think being connected to the circuit last time, was the
reason for the mulitmeter giving me a reading of 91 nF. The capacitor
is of the old metal cased type, made in 1966, installed in the base of
an old electric fan. I'm guessing that since it returned an accurate
reading, I should just leave it.
from the circuit completely, and returned a more accurate reading of
1.248 uF. I think being connected to the circuit last time, was the
reason for the mulitmeter giving me a reading of 91 nF. The capacitor
is of the old metal cased type, made in 1966, installed in the base of
an old electric fan. I'm guessing that since it returned an accurate
reading, I should just leave it.
D
default
Guest
On Fri, 16 Nov 2007 22:17:53 -0800 (PST), "Dave.H"
<the1930s@googlemail.com> wrote:
(common aluminum types in particular)
The designer should have taking the tolerance in account when the
circuit was designed and allowed for the large variance.
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<the1930s@googlemail.com> wrote:
Sure. Many electrolytic's are specified at +200% to -20% capacity
(common aluminum types in particular)
The designer should have taking the tolerance in account when the
circuit was designed and allowed for the large variance.
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J
John Larkin
Guest
On Fri, 16 Nov 2007 22:17:53 -0800 (PST), "Dave.H"
<the1930s@googlemail.com> wrote:
best +-20% tolerance, and sometimes a lot worse (like -0, +50%, or
even GMV, guaranteed minimum value) it will probably be OK.
John
<the1930s@googlemail.com> wrote:
The context of your problem isn't clear, but since elec caps have at
best +-20% tolerance, and sometimes a lot worse (like -0, +50%, or
even GMV, guaranteed minimum value) it will probably be OK.
John
R
redbelly
Guest
On Nov 17, 6:36 am, "Dave.H" <the19...@googlemail.com> wrote:
You're looking to add 0.2 uF, or the equivalent, in parallel, yes?
Then you just need a bunch of caps that add up to 0.2 uF, all wired in
parallel.
Two 0.1 uF caps will add up to the necessary 0.2 uF.
Twenty 0.01 uF caps, though a rather silly thing to do, would also add
up to 0.2 uF.
Your suggestion (as typed) was to use two **0.01** uF caps, which
would only add up to 0.02 uF. Not what you want. Most people reading
this are probably assume you meant to say 0.1, and just typed 0.01 by
accident.
Mark
He was correcting a typo of yours.Hello!
20 times a 0.01
2 times a 0.1, off course!
Best regards,
Daniel Mandic
Sorry, I don't understand what you are saying. Please excuse my
almost non existent knowledge of elctronic circuits, I'm still
learning .
You're looking to add 0.2 uF, or the equivalent, in parallel, yes?
Then you just need a bunch of caps that add up to 0.2 uF, all wired in
parallel.
Two 0.1 uF caps will add up to the necessary 0.2 uF.
Twenty 0.01 uF caps, though a rather silly thing to do, would also add
up to 0.2 uF.
Your suggestion (as typed) was to use two **0.01** uF caps, which
would only add up to 0.02 uF. Not what you want. Most people reading
this are probably assume you meant to say 0.1, and just typed 0.01 by
accident.
Mark
E
Eeyore
Guest
"Dave.H" wrote:
0.2 isn't a standard value (except from some ancient US suppliers).
Graham
Use 0.22
0.2 isn't a standard value (except from some ancient US suppliers).
Graham
E
Eeyore
Guest
default wrote:
electrolytics.
Graham
Are you sure you mean +200% ? More like +50% max I'd have thought in the case of
electrolytics.
Graham
F
Fred Abse
Guest
On Fri, 16 Nov 2007 22:40:55 -0800, Dave.H wrote:
This wouldn't be a motor start/run capacitor would it?
They're special reversible types for AC use and should only be replaced
with a type characterized for that application.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
That rang a warning bell.
This wouldn't be a motor start/run capacitor would it?
They're special reversible types for AC use and should only be replaced
with a type characterized for that application.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
F
Fred Abse
Guest
On Sat, 17 Nov 2007 03:58:25 -0800, Dave.H wrote:
capacitors will not do, in fact will probably fail spectacularly, leaving
innards over everything.
At that vintage, it may well be a paper dielectric type, not an
electrolytic.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
See my earlier post about motor capacitors. "Regular" electrolytic
capacitors will not do, in fact will probably fail spectacularly, leaving
innards over everything.
At that vintage, it may well be a paper dielectric type, not an
electrolytic.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
D
default
Guest
On Sat, 17 Nov 2007 19:17:33 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
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<rabbitsfriendsandrelations@hotmail.com> wrote:
You're right, wikipedia gives it at -20 +50%
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John Fields
Guest
On Sat, 17 Nov 2007 10:11:58 -0800, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
Not true. They're available with 10%, 5%, and even tighter
tolerances.
--
JF
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
---
Not true. They're available with 10%, 5%, and even tighter
tolerances.
--
JF
J
John Fields
Guest
On Sat, 17 Nov 2007 19:15:37 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
You're full of shit, again, Graham.
Look on Digi-Key's website and you'll find lots of 0.2ľF from non-US
manufacturers.
--
JF
<rabbitsfriendsandrelations@hotmail.com> wrote:
---
You're full of shit, again, Graham.
Look on Digi-Key's website and you'll find lots of 0.2ľF from non-US
manufacturers.
--
JF
T
terryS
Guest
On Nov 17, 3:17 am, "Dave.H" <the19...@googlemail.com> wrote:
we may have been assuming (I certainly did intially) this is an
elctrolytic cap. operating on a DC supply of 240 volts?????
Are we sure it IS an 'electrolytic'????
1.2 mfd seems a small value for an electrolytic. At that size it is
not difficult to use a 'non electrolytic' as long as space is not a
series criterion? I have some old DC capacitors for example that are 4
mfd!
Could the capacitor possibly be an AC rated 'motor start' type
capacitor?
If the input IS 240 volts, RMS alternating, the peak voltage will be
in the region of 340 volts. Even if the capacitor is attached to the
out[put of a rectifier? the peak voltage it will encounter will be in
the same range of voltage?
It really would be best to know what is the application is! If an
incorrectly installed electrolytic exploded it could cost someone
their sight or perhaps skin burns!
Since the original posting does not specify the type of use
we may have been assuming (I certainly did intially) this is an
elctrolytic cap. operating on a DC supply of 240 volts?????
Are we sure it IS an 'electrolytic'????
1.2 mfd seems a small value for an electrolytic. At that size it is
not difficult to use a 'non electrolytic' as long as space is not a
series criterion? I have some old DC capacitors for example that are 4
mfd!
Could the capacitor possibly be an AC rated 'motor start' type
capacitor?
If the input IS 240 volts, RMS alternating, the peak voltage will be
in the region of 340 volts. Even if the capacitor is attached to the
out[put of a rectifier? the peak voltage it will encounter will be in
the same range of voltage?
It really would be best to know what is the application is! If an
incorrectly installed electrolytic exploded it could cost someone
their sight or perhaps skin burns!