casiomax said:
Hi Cas,
Pls note that 'earth ground' you mention will not improve sound or clear the humm..
It isn't audio network but safety network. even more sometimes connecting earth ground will causing humm problem to your amp, so that people install the disconnecting network.
if your main have no safety earth, pls take necessary to have it continue to built your own or hire an electrician for consultation. well insulated amp sud placed at the last choise.
i was having some precious advise from exprerienced here, but can't hold my self to make my own experiments to answer my curious. i sacrifies my DIY BJT amp wich full of fuses, metal case, metal knob just to know hows things work.
here are some fact n my 'personal' advice, thought, n resume :
safety earth is not popular in our country.
most of us skip to install the 3rd wire ( earth ) in our house electric network. which sud be 3 ( live - neutral - earth )
and.. today mostly simple electronic product not provide safety earth connection. 1 fuse is maximum.
and.... we both knows that so many people dead and injured for being electrocuted.
- i assume that 'live' character is always very want to bites 'neutral', and always conduct to all metal.
- all conductive parts must connect to safety earth, also your amp network ground which they will also connected to at least : exposed input jack, and speaker. in case it is causing humming, use a disconnecting network, then insulated them from metal case.
why 'I' need earth ground for safety?
the fuses will succesfuly ruptured if :
( 'DONT TRY THESE!!')
- 'live' bites 'neutral'.
- 'live' conduct well safety earthed metal enclosure such : metal case, knob etc.
( my fuses were as sensitive as 0.25A and my earth was well connected to abandoned water pump pipe ). seems someone has told me the truth about : FUSE will rupute if take different loads. and... the earth ground make it.
when the live wrongfuly conduct your metal case, what will happen if you are not connect the the safety ground?
well, sometimes no explotion, but the 220VAC live will bites person who touch your amp, will bite you more nicely to death especialy when you're wet.
here are some result from my experiment :
- connect live to neutral without any fuse : my house main oto fuse down.
( if the fuse is too thick / strong, my guess : the live will keep happyly bites the neutral and burn all around caused of their fireworks, and then my house )
- connect live to neutral with main fuse : the fuse ruptured
- connect live to not earthed amp metal body : nothing happen
( as i said : its conductive! who will touch it anyway )
- connect live to earthed amp metal body : main live fuse ruptured.
more curious development :
- short amp network randomly with screw jack : fuse on PCB ruptured, the amp just OK after that.
- short amp network randomly with screw jack without fuse on PCB :
the trafo humming loudly.... fireworks..... i'm waiting till the main fuse ruptured..... its not! i cant hold any longer, the trafo seems will explode soon..
the trafo was as hot as fire when i touch.
amazingly, the trafo and the amp entirely just OK after that 😀 i don't understand......
i bet if it was chipamp, there will be smokes and baad burned chip smell.
I'm not a well educated person who told you all of this, maybe there are more information like power load also make the fuse get ruptured, or anomalis... i haven't been there..
a long writting, but i'm just feel guilty if not warn you about this.
My english is worse, i will explain you in our language PM if you want. just take it necessary, i'm about to save your live hehehe
'longlife DIYers!! 😀
Hwoow, nice to hear that from you! soon you will have to leave the ..eureka-forever newbe..
you've learned quit a lot, bro😎 but may I repeat loudly your warning 'DONT TRY THESE!!', DONT EVEN THINK OF TRYING some of the obvious things unless you know exactly what you are doing!!!
are you sure? what they are used to protect for? even my cellphone charger is rated at 0.355A
you seemed to be very adventurous yet very cautious at the sam time🙄 If I dont find you post here for more than a week, I'll send a squad to find you in Borromeus or Hasan Sadikin😀 😀 😀
No Edits,
nothing but my curious.after reading some thread here i was just realized that some of my house electric instalation are wrong. some of lamp switch is on neutral etc.. nextmonth we will renov our house, the main instalation will also re-setting.
i was missed to test : Neutral to earth, even someone here ( Mr Gareth ) said that neutral & earth coming from same source, thats why none put fuse at neutral,even theres no light in our testpen, but i guess it will also 'fireworks' if they're connected, i don't know. maybe someone will tell us what will happening..
before an officer kick me out from here for doing jackass,
here are my very valuable advice for you indonesian.. (haha) :
- use double fuse for mains, 1 for neutral, 1 for live.
why? because we knows our prongs, live wire can be at right side or left side.not fixed like other country somewhere , 3 fixed position prongs hardly to wrong placed. so hows the fuse will rupturing if live wire contacts conductive parts if it at wrong side.
- if your fuse get ruptured, don't turn on your amp before you know and be sure that the problem have been solved. the wrong wiring still there if you only replace with a new one.
- don't replace the fuse with greater, fireworks and more accidents happened due to the fuse too strong to ruptured.
1 get ruptured means 1 time saving action.
Brgds.
Eka
nothing but my curious.after reading some thread here i was just realized that some of my house electric instalation are wrong. some of lamp switch is on neutral etc.. nextmonth we will renov our house, the main instalation will also re-setting.
i was missed to test : Neutral to earth, even someone here ( Mr Gareth ) said that neutral & earth coming from same source, thats why none put fuse at neutral,even theres no light in our testpen, but i guess it will also 'fireworks' if they're connected, i don't know. maybe someone will tell us what will happening..
before an officer kick me out from here for doing jackass,
here are my very valuable advice for you indonesian.. (haha) :
- use double fuse for mains, 1 for neutral, 1 for live.
why? because we knows our prongs, live wire can be at right side or left side.not fixed like other country somewhere , 3 fixed position prongs hardly to wrong placed. so hows the fuse will rupturing if live wire contacts conductive parts if it at wrong side.
- if your fuse get ruptured, don't turn on your amp before you know and be sure that the problem have been solved. the wrong wiring still there if you only replace with a new one.
- don't replace the fuse with greater, fireworks and more accidents happened due to the fuse too strong to ruptured.
1 get ruptured means 1 time saving action.
Brgds.
Eka
0.25 mA on the mains side means 2.5 A on the secondary. Not that much but they will probably be good for an LM18XX.
i have measuring:
weight: 1,6 KG
height: 5 cm
diameter out:10.5
diameter in: 4.8
please help me to guess VA of this trabnsformer? thx
I would guess, 150-200va.
Look here, scroll down and see the chart
http://www.toroid.com/custom_transformers/custom_toroidal_transformer.htm
hth,
7/10
Look here, scroll down and see the chart
http://www.toroid.com/custom_transformers/custom_toroidal_transformer.htm
hth,
7/10
hi Indonesian Friend
sorry for off topic. where do you guys source the tranformer in indonesia? i am leaning this new hobbies and would like to diy. thanks in advance
sorry for off topic. where do you guys source the tranformer in indonesia? i am leaning this new hobbies and would like to diy. thanks in advance
toroid way to expensive!!
Try this site:
http://www.antekinc.com/
I looked up the transformer I want at toroid.com and
it is 131$..😱 same 48-0-48 at antek is 84$ ,bigger too,
16lbs. vs 13lbs. for same 800VA unit. Antek ships international
for 37$ , US 20$..
check it out...
Just read the whole thread in 60 seconds , you all have sound
ideas to make a good PS (I already use dual snubbed rectifiers,
multiple overrated caps,star ground,etc.)
Happy DIYing,
OS
Try this site:
http://www.antekinc.com/
I looked up the transformer I want at toroid.com and
it is 131$..😱 same 48-0-48 at antek is 84$ ,bigger too,
16lbs. vs 13lbs. for same 800VA unit. Antek ships international
for 37$ , US 20$..
check it out...
Just read the whole thread in 60 seconds , you all have sound
ideas to make a good PS (I already use dual snubbed rectifiers,
multiple overrated caps,star ground,etc.)
Happy DIYing,
OS
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