Thanks for all the help! much appreciated
OrganiK
Member
Last Activity: 05-22-2019, 03:05 PM
Joined: 05-15-2019
Location: Comares
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Re: Broken transformer on Carlsbro GRX7
Thanks for all the help! much appreciated
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Re: Broken transformer on Carlsbro GRX7
I know but can't i make one with a a center tap with a transformer that has 2 identical secondary windings?...Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
Nice one, so then i would need a transformer that has 2 secondarys with an output of about 50Vac each correct?...Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
The caps are rated at 80VDC so its a bit high for 30 right? but maybe since its old school they like to over engineer stuff a lot, dunno.
If it was 43Vac on either side it would give about 56Vdc for each cap that makes more sence for the 80VDC on the caps. we also know that its a 150W x2 amp at 2omh so that would need a voltage of about 17Vac = 24.5Vp so that fits better with it being 43Vac total.
Thanks a lot for you time and patients by the way...Last edited by OrganiK; 05-16-2019, 11:58 AM.Leave a comment:
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Re: Peavey 600E amp/mixer
Is this it?
You can also check the regulators on the power supply, I had a hum come fron blown regulators before and you they don't always go dark when they doLeave a comment:
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Re: Broken transformer on Carlsbro GRX7
Non of the wires where connected, I put the connectors on them wire.
Yer I also wondered if someone had put a different transformer in it.
So where did you get the 43V on the secondary before? was it just a guess?
Edit: Sorry my bad i was just being stupid and could not read the sticker properly it says 43V 3 Amps on it...
and the caps are doble that, so could well be the right voltage. So do you think i should just try and fit a 2x 43V 150VA Transformer and cross my fingers?...Last edited by OrganiK; 05-16-2019, 01:56 AM.Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
no they are, there is one for each power rail...Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
what from the inrush current? i though that only happend on caps or motors, im really not sure so please correct me if im rong...Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
yer that's what i thought, Still i recon you right about there should be a center tap on the secondary tho...
Havent got means of getting 120vac... i might be able to borrow an old building transformer, that should do right?.
Still dont quite understand why it would blow the fuse by putting more volts on it if there isn't any load on the secondary...Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
Even if there is no load on the secondary? would a single primary winding not have a high impedance when there is no current flowing though the secondary?...Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
There seems to be no sing of the center tap on the transformer, you're right about there being a ground terminal in between the 2 caps. Maybe the center tap wire has broken off in side, behind one of the other ones... but I can't see anything behind them
Here's a drawing I just done if it helps
the orange ones were connected together when I got it....Last edited by OrganiK; 05-15-2019, 05:52 PM.Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
here are some more photos, so there is a blue and green one on the side with one winding...Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
you are right, it is a +/- supply, there are 2 big caps and i just found the GND terminal in in between them!
But still one of the windings that is on the side where there is 2 is open circuited.
Also the DCR mesures 0.6 ohms on the single winding side, and 3.6 on the other winding. that makes me think that i have it the right way round. because there the VAC will be lower on the secondary therefor there will be less turns and les DCR. Right?
And despite all of that, when i connected it...Last edited by OrganiK; 05-15-2019, 01:27 PM.Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
here are some pictures, were i show both sides of the the transformer, on one side, the one with 2 windings there is a small misterios hole, the board has a 2 terminals, tagged with +V and -V but there is no GND terminal or tag, so I think it is just a single rail and the -V is just the ground.
Thanks for you quick responses...Leave a comment:
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Re: Broken transformer on Carlsbro GRX7
Pretty sure it is this way round, since the wires are much thicker on the single winding side and the DCR is 0.6 on that side.
Good thinking tho, i ques its a single rail power supplyLeave a comment:
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Broken transformer on Carlsbro GRX7
Hi all, to summarize I cant work out what the windings ratio, or rather what the VAC output of the transformer is.
A cliente came in with this GRX7 that is a mixer/power amp, quite old thing. Said it stooped working so he opened it up, saw a loose wire and connected it to where he though it went, but of course that didn't fix.
So i open it up and found the transformer was not connected up.
The transformer has 2 primary windings, and 1 secondary winding I live in Spain and we have 240VCA so naturally the to primary coils where connected together, but there... -
Re: New Members - please post your introductions here
Hello everybody, I'm a newbie electronics technician with a fair amount of experience in the would of sound, just finished 4 years of electrical studies here in Spain, but i still got a LOT to learn so that's why I'm here, and hopefully i can be helpful to other as well.Leave a comment:
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