Nordic said:
Nope, regulare glass fuses no slowblow
Yes. the inlet is made that way.Nordic said:
Also it seems like you have fuses on both L and N?
An externally hosted image should be here but it was not working when we last tested it.
I would keep a fuse only on L, you are getting into fire and electical hazzard danger area fuseing both... if you want to use 2 fuses, use them after your PSU...
I thought those white thingies were your fuse holders... but it seems to be in the IEC connector drawer... sure it uses 2 fuses?
I'm not saying this is the reason... but you likely have a toroidal transformer.... which causes quite a current inrush on powerup...
get a few slowblow fuses, also called T-fuses they normay have a T before the current rateing on the cap...
I thought those white thingies were your fuse holders... but it seems to be in the IEC connector drawer... sure it uses 2 fuses?
I'm not saying this is the reason... but you likely have a toroidal transformer.... which causes quite a current inrush on powerup...
get a few slowblow fuses, also called T-fuses they normay have a T before the current rateing on the cap...
There are two fuses in the IEC connector drawer (link ), if I remove one of then there will be no connection on the corresponding plug..Nordic said:
So I’m not sure how to use only one fuse?
Would it be a terrible idea to use a 10A as “a no fuse connection”, and one 4A slowblow as the “working fuse”?
Nordic said:
I’m on my way to the local electric components pusher.. Whish value slowblow fuses should be sufficient?
500 / 230 = ca 2,2A + the power on inrush??
There is no secret I’m a total DIY newbie..
Nuuk said:Use a 3.15AT (slow blow) fuse.
Don't some of those fused IEC sockets allow you to house a spare fuse in the drawer as well as the one that is actually functional?
Doh..
Now I should dig a virtual hole and hide in it…
[BadExuseStart]
When I blew my fuse, the”explosion” also destroyed the spar fuse in the neighboring drawer...
which caused me to start beliving there actually where two”active” fuses..
[BadExuseEnd]
So I do have only one fuse on the primary side.
Have just returned from the locale electronics pusher with a bag containing 10 3,15A slowblow ceramic fuses (they were out of glass ones)..
QUESTION1: Is there a requirement to attach the power supply to test if the Toroid transformer works?'
[Edit]
Have tested the new fuses.. And it Works.. Or at least the transformer works.. My power Supply doesn’t..
QUESTION:
Should there be a connection between the white cords and the hole to the right of them..
http://chipamp.com/images/ps.gif
Attachments
Right you are squire... there is you error right there.... because you share a transformer... the 2 PSU's go in parallel with each other... Not the way you have it now...
From what I understand your transformer puts out 0-20-0-20
The first 0 goes to one AC point on your PSU, and the last 20 goes to the other AC connector... the connection of the two centre wires from the transformer is apparent...
I.e. there should be at least 4 connections between the psu and the transformer... just set up one PSU first.. in case you make a mess... less components to replace...
From what I understand your transformer puts out 0-20-0-20
The first 0 goes to one AC point on your PSU, and the last 20 goes to the other AC connector... the connection of the two centre wires from the transformer is apparent...
I.e. there should be at least 4 connections between the psu and the transformer... just set up one PSU first.. in case you make a mess... less components to replace...
An externally hosted image should be here but it was not working when we last tested it.
Nordic said:
Hmm,,
I’m not sure I quite catch it.
My transformer has 2 pair’s as secondaries.
Green 20V, Red 0. And
Brown 20V, blue 0.
I have two psu boards which each has 4 inputs.. See pictures for details,
Pic 1: http://chipamp.com/images/ps-rev3-sch.gif
pic 2: http://www.briangt.com/gallery/albums/lm3886amp/3886_019.jpg
AC1 and AC1
AC2 and AC2
How should these two components be put together?
should it be someting like:
Green 20V --> AC1
Red 0V --> AC1
Brown 20V --> AC2
Blue 0V --> AC2
and this should be the same for both psu boards?
Hi,
Your 500VA should not exceed 2.3A when at full load.
To allow reliable starting one may require upto 7A fuse without suffering nuisance blowing (about 3times the maximum power current =1500/220=6.8A)
Using a T rated fuse (= slow blow = anti-surge) you may get away with a slightly lower value fuse, try T5A or T6.3A
If you want/require to use a close rated fuse (T2.5A) then you will need to add a soft start to reduce the start-up current. You may find that your amp will operate successfully with a T2A fuse as you originally fitted, even at full power on both channels.
50r in series with the transformer primary reduces the current, but absorbs an enormous amount of power and overheats very rapidly. One must use a relay to bypass the resistor quickly to avoid it burning out. A time delay on the relay bypass of between 300mS and 1S is usually OK.
The soft start resistor can be made from 5off 10r 5W resistors in series.
Your choices are:-
high rated fuse and the higher fault current that will flow before the fuse ruptures
or
soft start and close rated fuse
Next,
build a light bulb tester to plug into the mains to allow safe starting on ALL new mains powered projects and use it EVERY time you modify a mains powered project. This prevents catastophic blowups, saving much expense and can avoid dangerous explosions damaging your eyes or anyone else nearby.
Your 500VA should not exceed 2.3A when at full load.
To allow reliable starting one may require upto 7A fuse without suffering nuisance blowing (about 3times the maximum power current =1500/220=6.8A)
Using a T rated fuse (= slow blow = anti-surge) you may get away with a slightly lower value fuse, try T5A or T6.3A
If you want/require to use a close rated fuse (T2.5A) then you will need to add a soft start to reduce the start-up current. You may find that your amp will operate successfully with a T2A fuse as you originally fitted, even at full power on both channels.
50r in series with the transformer primary reduces the current, but absorbs an enormous amount of power and overheats very rapidly. One must use a relay to bypass the resistor quickly to avoid it burning out. A time delay on the relay bypass of between 300mS and 1S is usually OK.
The soft start resistor can be made from 5off 10r 5W resistors in series.
Your choices are:-
high rated fuse and the higher fault current that will flow before the fuse ruptures
or
soft start and close rated fuse
Next,
build a light bulb tester to plug into the mains to allow safe starting on ALL new mains powered projects and use it EVERY time you modify a mains powered project. This prevents catastophic blowups, saving much expense and can avoid dangerous explosions damaging your eyes or anyone else nearby.
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