kneadle said:
As far as i can see those are the only connectors of that type... so jason is right, those 2 pinsa are 115V AC in, and you have 2 secondary voltages... from the cap ratings 50-60V & 30-35V, both centertapped.
The higher V will have the higher current rating , but the voltage is somewhat high. It might be possible to rewire the secondary for 230V in (there are those 2 extra wires) and still run it off 115V & halve the secondary voltages.
dave
Banned
Joined 2002
Banned
Joined 2002
Banned
Joined 2002
What he said.
Being shocked isn't as big a concern for me as seeing the safety (fuse, GFCI, circuit breaker etc. ) pop. it always makes an awfully sudden, sometimes loud noise and you realize that you were
--> . <-- that close to a LOT of juice.
And, to be perfectly honest, the first couple of times you see that fuse blow out of the corner of your eye, it will scare the poop out of you!
with your project!
If you blow several in a row (like *some* of us have
) you may be a bit shaky for a while and not want to play for a while
Trust me, we have all been right where you are before and hopefully will be again. Everybody blows stuff up sometimes. BUT (and this is a big but) you are extremely UNlikely to do any damage to anything except your cheap-or-free part.
Go for it.
/edit: I don't think anybody really likes plugging in untested transformers.
Being shocked isn't as big a concern for me as seeing the safety (fuse, GFCI, circuit breaker etc. ) pop. it always makes an awfully sudden, sometimes loud noise and you realize that you were
--> . <-- that close to a LOT of juice.
And, to be perfectly honest, the first couple of times you see that fuse blow out of the corner of your eye, it will scare the poop out of you!
with your project!If you blow several in a row (like *some* of us have
) you may be a bit shaky for a while and not want to play for a while Trust me, we have all been right where you are before and hopefully will be again. Everybody blows stuff up sometimes. BUT (and this is a big but) you are extremely UNlikely to do any damage to anything except your cheap-or-free part.
Go for it.
/edit: I don't think anybody really likes plugging in untested transformers.
Banned
Joined 2002
touche = touch.
toungue is easier.
Put your AC voltmeter on the secondaries and see what you get relative to whatever else there is. Looks from the pictures like you may have two center-tapped secondaries. Measure from one pin to all the others and make a chart. At least a couple of outputs will make sense. Be sure to check for two sets of very-close voltage secondaries lined up like this:
sec1a centertap sec1b sec2a centertap sec2b
if this is the case, the transformer is useful for voltages of
sec1a-sec1b
sec1a (or b)-centertap
sec1a-CT-sec1b
and similar for secondary #2.
recording the primary voltage at the time of measurement is useful if you have plans to rewind it for a different combination of volts and amps, but it sounds unlikely at this point!
toungue is easier.
Put your AC voltmeter on the secondaries and see what you get relative to whatever else there is. Looks from the pictures like you may have two center-tapped secondaries. Measure from one pin to all the others and make a chart. At least a couple of outputs will make sense. Be sure to check for two sets of very-close voltage secondaries lined up like this:
sec1a centertap sec1b sec2a centertap sec2b
if this is the case, the transformer is useful for voltages of
sec1a-sec1b
sec1a (or b)-centertap
sec1a-CT-sec1b
and similar for secondary #2.
recording the primary voltage at the time of measurement is useful if you have plans to rewind it for a different combination of volts and amps, but it sounds unlikely at this point!
Kneadle is wheedling.
a transformer is two pieces of wire. they are wound around the core a zillion times or less. usually less. if there is an electrical contact to the wire in the center of the length, it is a center tap. it will (for secondaries) have half the voltage across it relative to one end, that the ends have to each other.
it is a tap
in the center.
use it for a 0V reference
or not.
lucky I am tired or you would have to spend 2 minutes on google.
/edit: you have the same name as my grandfather's only son gave his only son.
a transformer is two pieces of wire. they are wound around the core a zillion times or less. usually less. if there is an electrical contact to the wire in the center of the length, it is a center tap. it will (for secondaries) have half the voltage across it relative to one end, that the ends have to each other.
it is a tap
in the center.
use it for a 0V reference
or not.
lucky I am tired or you would have to spend 2 minutes on google.
/edit: you have the same name as my grandfather's only son gave his only son.
Finally...
...I worked up enough nerve. Here is the voltage assignment using this picture as reference:
From top to bottom are pins 1-8.
Here's the voltage I could get out of them:
1+??=0
2+3=47
3+4=47
2+4=94
5+6=20
5+7=40
6+7=20
1+8=3
Every other combo yielded 0 volts.
Now...
What can I build to accomodate this Tx?
Dave
PS--and I didn't die!
...I worked up enough nerve. Here is the voltage assignment using this picture as reference:
An externally hosted image should be here but it was not working when we last tested it.
From top to bottom are pins 1-8.
Here's the voltage I could get out of them:
1+??=0
2+3=47
3+4=47
2+4=94
5+6=20
5+7=40
6+7=20
1+8=3
Every other combo yielded 0 volts.
Now...
What can I build to accomodate this Tx?
Dave
PS--and I didn't die!
Be happy. This is a useful transformer. To me it looks like you have output secondaries of:
47-0-47
20-0-20
3
or
94
40
3
rectified, roughly
66-0-66
28-0-28
4.2
The 28V taps are good if you want to do the chip amps forum's darling, the gainclone. A simple amplifier that can be built in an afternoon for less than $20 (by far) and that will sound, quite possibly, amazing. The higher voltage taps could also be used for a single supply gainclone.
The nice thing about DIY audio: think about what you want to do, and then design or copy a design and do it how you want. Almost any power amp design can be adapted to use this tranny!
If the output devices from the old amp are any good still (not hard to check) then you may be able to reuse them as well, with their heatsinks if they prove adequate.
Consider it useful to maybe 80% of the input power rating of the device it came from, or be optimistic and say it can give you 100% of the output power rating!
/edit:
The 4V output can be for indicators or low-level logic if you want. Or some crazy biasing scheme i guess but...
And go easy on the output transistor leads. Bend them too much (as few as once or twice more) and they will break!
47-0-47
20-0-20
3
or
94
40
3
rectified, roughly
66-0-66
28-0-28
4.2
The 28V taps are good if you want to do the chip amps forum's darling, the gainclone. A simple amplifier that can be built in an afternoon for less than $20 (by far) and that will sound, quite possibly, amazing. The higher voltage taps could also be used for a single supply gainclone.
The nice thing about DIY audio: think about what you want to do, and then design or copy a design and do it how you want. Almost any power amp design can be adapted to use this tranny!
If the output devices from the old amp are any good still (not hard to check) then you may be able to reuse them as well, with their heatsinks if they prove adequate.
Consider it useful to maybe 80% of the input power rating of the device it came from, or be optimistic and say it can give you 100% of the output power rating!
/edit:
The 4V output can be for indicators or low-level logic if you want. Or some crazy biasing scheme i guess but...
And go easy on the output transistor leads. Bend them too much (as few as once or twice more) and they will break!
I'm building a BrianGT right now. Of course, I had already bought the necessary transformers from Avel for both the amp and one of Nuuk's preamp designs (at decdun.com somewhere).
HOWEVER, this amp and preamp will be powering the HohlFlutes I just built for my dear bride, so now I have the Transformer taken care of for BOTH an additional BrianGT kit and a Nuuk preamp for myself.
I'm very happy; 47 and 20. Well, 47 might be a little hot for an LM3875. I'll have to look into that. Still, very feasible, I should think!
Dave
HOWEVER, this amp and preamp will be powering the HohlFlutes I just built for my dear bride, so now I have the Transformer taken care of for BOTH an additional BrianGT kit and a Nuuk preamp for myself.
I'm very happy; 47 and 20. Well, 47 might be a little hot for an LM3875. I'll have to look into that. Still, very feasible, I should think!
Dave
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.