DIY PSU & Regulator

[The Grand Wazoo]

I know we have to ere on the safety side but come on chaps give the guy a break and some helpfull feedback.

Sorry, but we have to consider not just those following the thread here and now, but those who come later to read it. This will remain available for anyone to see for a long time after we've all forgotten about it and although we'd like to think AoS members have a little sense about such things, there are a hell of a lot of idiots out there.

[Qwin]

Good advice

[DarrenHW]

Updated photo’s of my PS, they’re not great as only taken with my phone as I was working on it. I’ve tried to show all my work but did struggle to take some photo’s (no Macro option) so apologise for the poor quality. If anyone see’s any mistakes / room for improvement please let me know.

First up soldered connections to IEC including new chassis ground wire.

IMG_3788.jpg

This is the same IEC connector form my old enclosure and one of my first area’s of confusion in the last few posts. This is fitted with a 250ma slow blow fuse, which I took from the stock Technics PCB, is there something wrong with this / should I replace it with a fast blow fuse?

Soldered connections insulated and showing grounding to chassis.

IMG_3792.jpg

I had done this prior to Neal’s post;

Darren when you come to earth the box create an earth post with a bolt/screw and use serrated washers so they cut into the aluminium and form the best possible bond.

so revised the mounting to provide a better bond to the chassis, thanks for the input . This is the other area that caused confusion, this is all I wanted to achieve, is this ok?

IMG_3795.jpg

Soldered connections to switch.

IMG_3794.jpg

[DarrenHW]

The wires coming from the Toroidal are tiny single core wires, I made a few attempts at soldering these to the PCB but just couldn’t get a good solder. I did give it a bloody good try and testament to the quality of Ken’s board’s it stood up to the abuse well, but it just wasn’t happening. Taking inspiration (and parts) from an old Onkyo Amp I have in my HiFi “Boneyard” I decided to solder mounting pegs (I don’t know what they’re really called) to the board to wrap the wire’s around. As the wire from the tranny is such a **** (insert favourite expletive here) I wanted to solder the wire first and then solder the pegs to the PCB. This is where we get to the point where another electrical safety warning should probably be inserted! To do this I “modified” one of my soldering irons to turn it into a solder bath, wrapped the wire around the peg, fluxed and then dipped it.

IMG_3801.jpg

I haven’t yet been able to get a good photo of this, there was some heat damage to the outer but this has only distorted it nowhere is the wire exposed.

IMG_3806.jpg

Time to take a reading.

IMG_3817.jpg

Fluctuates between 40.7 – 40.9 Vdc.

Everything mounted and insulated showing the connection to umbilical, the shield drain is not currently grounded to the chassis as I couldn’t get a 3 pin connector at the weekend, I will revist this when Maplin have more stock.

IMG_3808.jpg

IMG_3810.jpg

[DarrenHW]

IMG_3812.jpg

IMG_3814.jpg

Okay, so I know anodised red won’t be to everyone’s taste and I wouldn't have chose it myself, but this started life as a Horticultural Lighting Ballast which I pulled it out of a skip attached to a very large light, (I think this used to be owned by an enthusiast Tomato farmer ) so it cost me absolutely nothing! I'm not sure if I'm imagining it or not but there may be a further reduction in background noise, I don’t know whether this is due to better shielding from the toroidal, lower voltage output, grounding the chassis or just good old fashioned placebo effect?

Venting will be added to the bottom of the chassis as soon as I have picked up a round file, I've been testing it with the lid off. Marco came round yesterday for a 7 hour "sesh" / setup and the PSU performed without fault.

Thanks for everyone's input and help with this .

[NRG]

Well done Darren, that looks much better. Did you continuity test the earth connection with the box? The transformer wires are enameled they can be a pain as you noted. If the soldering iron won't burn the enamel off you need to resort to fine wire wool or that green cleaning stuff to scrape it off prior to soldering.

[Qwin]

Darren - did you try scraping the single strand of copper before soldering. It may have been coated wire like they use on windings. A scrape with a blade usually removes the coating and allows easy soldering. If you keep aplying heat the coating will eventually burn off which I think is what you may have done when you managed to achieve the joint - bear this in mind if you have trouble in the future as solder takes well to good clean copper, if it doesn't there's usually a reason.

Jazzy looking case.

edit: I see Neal said the same thing while I was typing.

[DarrenHW]

Well done Darren, that looks much better. Did you continuity test the earth connection with the box?

Thanks Neal. Yes. continuity tested. After reading your post I used one of the serrated washers to scrape all the anodising off so the connection was to bare metal, there is also (as you suggested) a serrated washer beneath the earth ring which is not visible in the photo.

The transformer wires are enameled they can be a pain as you noted. If the soldering iron won't burn the enamel off you need to resort to fine wire wool or that green cleaning stuff to scrape it off prior to soldering.

Darren - did you try scraping the single strand of copper before soldering. It may have been coated wire like they use on windings. A scrape with a blade usually removes the coating and allows easy soldering. If you keep aplying heat the coating will eventually burn off which I think is what you may have done when you managed to achieve the joint - bear this in mind if you have trouble in the future as solder takes well to good clean copper, if it doesn't there's usually a reason.

I see, and again highlighting my lack of knowledge for which I do appreciate your input and concern. Explains why they were such a git to solder, maybe if I'd known this first I could have soldered directly to the PCB I assumed I was struggling to get a good joint as the wires were so much smaller than the "hole" in the PCB.

Cheers !

[NRG]

You did the right thing by using a PCB 'pin' to solder to Darren, the fine wire makes a better connection to these than to the PCB directly.

[DarrenHW]

You did the right thing by using a PCB 'pin' to solder to Darren, the fine wire makes a better connection to these than to the PCB directly.