I've got a cassette deck - still used for educational material - that
has failed and it would appear that a device called a "fuse resistor"
in the voltage regulator circuit has gone open circuit. It's defined
as 3.3 ohms, 1/2w and the service manual indicates 1 volt across it,
indicating a current of 300ma.

Although RS stock something similar, there is not an immediate
replacement. Is there someone here who could advise me if I could
replace it with a 3.3 ohm resistor and a 500mA fuse ? I'm hoping of
course that it is just old age that has gone for it and not something
further down the line.

Thanks

Rob

On 15 Mar, 19:47, robgraham wrote:
I've got a cassette deck - still used for educational material - that
has failed and it would appear that a device called a "fuse resistor"
in the voltage regulator circuit has gone open circuit. *It's defined
as 3.3 ohms, 1/2w and the service manual indicates 1 volt across it,
indicating a current of 300ma.

Although RS stock something similar, there is not an immediate
replacement. *Is there someone here who could advise me if I could
replace it with a 3.3 ohm resistor and a 500mA fuse ? *I'm hoping of
course that it is just old age that has gone for it and not something
further down the line.

Thanks

Rob

I've been told on another forum that they are called 'Fusible
Resistors'. I've now found several suppliers via Mr Google.

Rob

robgraham wrote:
I've got a cassette deck - still used for educational material - that
has failed and it would appear that a device called a "fuse resistor"
in the voltage regulator circuit has gone open circuit. It's defined
as 3.3 ohms, 1/2w and the service manual indicates 1 volt across it,
indicating a current of 300ma.

Although RS stock something similar, there is not an immediate
replacement. Is there someone here who could advise me if I could
replace it with a 3.3 ohm resistor and a 500mA fuse ? I'm hoping of
course that it is just old age that has gone for it and not something
further down the line.

Thanks

Rob

Yes, resistor plus fuse does the same job.


NT

wrote in message
...
robgraham wrote:
I've got a cassette deck - still used for educational material - that
has failed and it would appear that a device called a "fuse resistor"
in the voltage regulator circuit has gone open circuit. It's defined
as 3.3 ohms, 1/2w and the service manual indicates 1 volt across it,
indicating a current of 300ma.

Although RS stock something similar, there is not an immediate
replacement. Is there someone here who could advise me if I could
replace it with a 3.3 ohm resistor and a 500mA fuse ? I'm hoping of
course that it is just old age that has gone for it and not something
further down the line.

Thanks


Fusible resistors often fail for no good reason, although of course, there
may be be a downstream fault, which is what they are there to protect
against ...

I would say on average, that I replace at least 1 or 2 fusibles a month in
all sorts of audio equipment, and maybe a couple a year have failed for a
'real' reason. I wouldn't be *too* paranoid about getting exactly the right
value, nor about adding a fuse as well. As long as any replacement that you
fit is 'ballpark', it will still fail in short order, if a genuine fault
occurs at some time in the future. That said, you shouldn't have any problem
obtaining a replacement in a value of 3R3.

Arfa

In message , Arfa Daily
writes
I would say on average, that I replace at least 1 or 2 fusibles a month in
all sorts of audio equipment, and maybe a couple a year have failed for a
'real' reason. I wouldn't be *too* paranoid about getting exactly the right
value, nor about adding a fuse as well. As long as any replacement that you
fit is 'ballpark', it will still fail in short order, if a genuine fault
occurs at some time in the future. That said, you shouldn't have any problem
obtaining a replacement in a value of 3R3.

Arfa
One of the 'features' of the fusible resistors is that they don't burst
into flames when they 'fuse' so replacing one with a standard resistor
and fuse could have unintended safety implications.



--
Clint Sharp

"Clint Sharp" wrote in message
...
In message , Arfa Daily
writes
I would say on average, that I replace at least 1 or 2 fusibles a month in
all sorts of audio equipment, and maybe a couple a year have failed for a
'real' reason. I wouldn't be *too* paranoid about getting exactly the
right
value, nor about adding a fuse as well. As long as any replacement that
you
fit is 'ballpark', it will still fail in short order, if a genuine fault
occurs at some time in the future. That said, you shouldn't have any
problem
obtaining a replacement in a value of 3R3.

Arfa
One of the 'features' of the fusible resistors is that they don't burst
into flames when they 'fuse' so replacing one with a standard resistor and
fuse could have unintended safety implications.



--
Clint Sharp

Yes, agreed. Also, I wasn't implying that a different 'type' of resistor
should ever be fitted, although I can see reading my post again, that I
perhaps didn't make that clear, so let's put that right now. What I was
intending to mean was that any fusible resistor *value* in the right
ballpark - so a 2R2 or 4R7 - would not be a problem, if a 3R3 was not
readily available to the poster. Any replacement should also have a similar
power rating to the one being replaced, although this is not always apparent
just by looking. I have seen 1 watt fusibles that are smaller than 1/2 watt
ones. This is a situation where if you want to preserve the safety ratings
*exactly* as they were, a service manual with a parts list is needed, and if
that doesn't make clear what the power rating is, the replacement device
would have to be ordered from the manufacturer.

Arfa