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In Reply to: RE: Arrrrrgh! posted by vinnie2 on February 08, 2017 at 06:50:18
well drat.... just doesn't seem to be my night. I hooked the halo up to the filaments of an 813, and got a bit of a glow from it, and it was measuring 4.5 volts on my dvm. I started taking loops off the torroid and got down to about 1.4vac with 4 loops left on the torroid. then I hooked it up to a 26 and compared the brightness of the filament to a 26 in my preamp that I know is set at 1.5 vdc and they looked pretty close. Decided to try it in the bread board and was rewarded with a loud hum, so decided to put the same 550uf cap in that I used on the halos for the 813's. Got that set up and when I turned the juice on there was a bit of a crackle and then silence. No glow on the filament any more. Could it be the cap is to big for this little guy? Pic attached. Looking at the picture I just thought of another possibility too. On the 813 halos there are 4 diodes in front of the greedn cap and the wires were attached to the back pair. Could it be these wires should be attached to the diodes behind the cap? If so, I have one left I can experiment with tomorrow. At least they were cheap; just wish it didn't take so darned long to get them.
Edits: 02/08/17Follow Ups:
The 1 ohm (or similar) surge resistor burned open because of the capacitor. I can see it in the photo, next to the output toroid. This has all been discussed multiple times, I strongly suggest you go back and read the previous posts on using these devices. You need to replace the resistor with a standard 1/2W or 1W approximately 1 to 3 ohms. I also recommend using a smaller cap than 550uF. I've never attempted to power one of these with such a large filter. Again, discussed previously within the last month or so...
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Buy Chinese. Bury freedom.
Edits: 02/08/17
I don't think we discussed that particular item, and besides it would take me forever to go through all the posts that particular thread generated. Certainly a whole lot longer than it took you to type your post.
When I did the halos for the 813's I first used a cap that was way too small, so I thought I would start with a larger one this time.Thanks for the info.
Edits: 02/09/17
I think if you look at the back of the pcb that you will see that the diodes on either side are connected to each other at the edge of the pcb. they are also connected to the large green caps. It is just a simple diode bridge.
Presumably you remembered to observe the cap's polarity.
It's interesting that you got to such a low voltage. Perhaps next time you could start with the 550 uf cap attached and then remove the turns. Or as you suggest you could try a lower value cap.
ray
So it doesn't matter which pair you hook up to? I did observe the polarity.
If you measure the resistance between the diodes at the edges of the pcb, the resistance should be zero if your's are like mine. So you can connect to either.
ray
thanks!
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