Triac blowing fuses?

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Roy
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Triac blowing fuses?

Post by Roy » Sun 31 Jul , 2016 19:02 pm

My 1986 triac is blowing both of the 3.15 amp fuses (f2 & f3) on the power section of the pnc main board when the board is powered up.
Any ideas what would be causing this?

This is the only section of the board I use as I have piggy backed off of this for Mach 3 & been running fine for several years!
I have recently just moved the triacs electrics into a stand alone cabinet, but all wiring is exactly as it was before when everything was working fine.

Cheers Roy

alanhende
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Re: Triac blowing fuses?

Post by alanhende » Mon 01 Aug , 2016 6:09 am

Hi Roy,
Can you send me a picture of the area where the fuses are blowing. this will give me an idea of what version of pcb you have. It should be relatively easy to fix.

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Roy
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Re: Triac blowing fuses?

Post by Roy » Mon 01 Aug , 2016 9:01 am

Hi Alan,
Many thanks for your prompt reply.
Here is a view of the complete set-up in the old drawer, and then in the new cabinet.(a few weeks ago before wiring complete)
The last one shows a close up of the problem area, (fuses removed)
Its fuse F2 & F3 which are both 3.15 Amp time delay ones.
Cheers, Roy
Attachments
board.JPG
board.JPG (229.93 KiB) Viewed 2474 times
new box.JPG
new box.JPG (402.64 KiB) Viewed 2474 times
old cab.JPG
old cab.JPG (323.15 KiB) Viewed 2474 times

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Roy
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Re: Triac blowing fuses?

Post by Roy » Wed 03 Aug , 2016 9:29 am

Still trying to figure this out, I remember reading somewhere that if there is a problem with the 12v it automatically shuts down the 5v?
I have been using the old 12v supply for the stereo unit to power the 5v (via a voltage regulator) for my breakout board. Could this be part of the issue? Would seem strange though as was working fine :?

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Roy
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Re: Triac blowing fuses?

Post by Roy » Wed 03 Aug , 2016 18:19 pm

So I've now disconnected my use of the 12v stereo supply. Fuse f2 is now holding out, but f3 is still blowing, although not straight away as before.
Still puzzled :?

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Roy
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Re: Triac blowing fuses?

Post by Roy » Thu 04 Aug , 2016 11:06 am

Ok so having some success by not using the stepped down 12v (former stereo) supply and using a standalone supply for the breakout board power.
The fuses were holding out.
However after turning the drives off this morning & then switching them back on, this capacitor has blown. !!!
Whats going on? Is it possible this capacitor was on its way out and causing the fuses to blow?



Cheers, Roy
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Roy
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Joined: Tue 30 Jan , 2007 20:20 pm
Hardware/Software: 1986 Triac modified & running Mach 3
Location: Bucks, UK

Re: Triac blowing fuses?

Post by Roy » Tue 09 Aug , 2016 8:56 am

New capacitor fitted, now back to blowing fuse f3 every now and then??

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