Quad 303 power on light

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20-Jan-2018 04:14 PM

rico

rico

Posts: 6

Good day 

Everything is going smoothy with the update of my quad 303. I have two small road block ; I have a power on light on the heatsink , can the light be wired to the rectifier 

There is a light blue fuze holder that was bolt on to the square aluminiun plate protecting the connector of the transformer, is the fuze required, because, it is not part of the electrical circuit at this time

Richad T



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22-Jan-2018 11:56 PM

rico

rico

Posts: 6

Can can we add picture to this post ?

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30-Jan-2018 07:21 AM

EJP

EJP

Posts: 1443

If you're replacing the power-on light with the LED and 12k resistor suppied, they connect in series across the PSU capacitor, observing polarity.

If you're not replacing it leave it alone.

I've seen occasional 303s with additional fuses. I always remove them but if you're not up to that there is no harm in leaving them there.
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30-Jan-2018 06:20 PM

rico

rico

Posts: 6

https://photos-1.dropbox.com/t/2/AAClJrsgqfHZgMOlJhqYRKbIRkzSQIZUkuz-wT57gG7TrQ/12/733533613/jpeg/32x32/1/_/1/2/IMG_0107.JPG/EPDK-s8IGAQgBygH/KR0IKzMv7-KaoxqE-0tLPjreVhKuS6DjvsoTLYp1G5w?size=1600x1200&size_mode=3
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30-Jan-2018 06:41 PM

rico

rico

Posts: 6

I am trying to show picture without success ... 

I have an extra light installed on the heatsink transistor protective cover. As per diagram, the light is part of the transformer primary circuit with a resistor of 7.65 kohm, I am on 110 volt .

I do not know how the slow blow fuze come into place !

My question is : How do I install the light and fuze to the primary circuit of the transformer ? 

Or do I install this light to the PSU capacitor ? 

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31-Jan-2018 01:07 AM

EJP

EJP

Posts: 1443

I can't access that URL without a login.

The front-panel fuse is already in series with the primary. Any additional fuse should be in series with the secondary, or the DC south of the PSU capacitors.

I would seriously consider removing it if the front-panel fuse is still in place. Make sure it has the correct rating as per the front panel.
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01-Feb-2018 02:33 AM

rico

rico

Posts: 6

I will install everythig on the DC side of the rectifier !

Thank you !


RichardT 

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01-Feb-2018 03:27 AM

EJP

EJP

Posts: 1443

That's not what I said. If you put it there it will blow, as there are massive currents from the rectifier into the PSU capacitors. I said to put it south of thecapacitors.
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01-Feb-2018 05:36 PM

rico

rico

Posts: 6

Sorry about that ! Then explain to me : ''South of the capacitor''


Best regards 

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02-Feb-2018 01:11 AM

EJP

EJP

Posts: 1443

Considering the mains as the North Pole, going south you encounter the PTX primary, secondary, rectifier, PSU capacitors, regulator PCB, amplifier boards, ...
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