doing cordwood, on perf, with DIYLC. much reading.

[duck_arse]

I think they are limited by the 10uF radial electros banging on the top of the transistors. you probably don't want to try and push them together too hard, so leave a little lead each end of your biggest intended part, will allow a little strain relief.

[digi2t]

Gotcha! 10q.

[amptramp]

I mentioned cordwood once and now there is a thread with people willing to do it.  What have I done?

[digi2t]

I mentioned cordwood once and now there is a thread with people willing to do it.  What have I done?

[duck_arse]

how did you get my photo, dino?

and amptramp - a search reveals more than one mention.

[amptramp]

^^^

A search shows 12 mentions of cordwood, ten of them referring to electronics and five of those by me and I know of at least one of my mentions that did not show up in the search.  We used to have a lot of surplus shops around here and cordwood was the ultimate in density in the 1950's.  We still had draftsmen working on upgrades to cordwood modules in the 1970's, mainly to accommodate parts that had gone extinct.  For this type of layout, sanity is not necessary.  Or desirable.

[duck_arse]

mounting thoughts - since forever, I've been employing "the stumbling block mounting method". smart builders will do well to avoid doing the same. planning ahead, you might do one of the following:

- work out some sort method using blocks and brackets before you solder, then cut your boards so they have mounting holes at the same end, as I did w/ the superfuzz.
- better, rotate one board so you have high mounting holes at one end, low holes at the other. then you will have clearance both ends for screws and mounts.
- or, cut your upper board to the circuit-size, and the lower to circuit-size plus 2/3 extra rows plus normal mounting holes on the other end. then mount via the lower board only, on spacers or whatever. or make the upper the longer board, and use those overlong threaded pillars you've got lurking in the drawers and hang the build via the upper.
- cut and glued plastic to form slots and runners, mount the boards on edge.

if you have any other methods in mind, please, do tell.

one thing about board directions - I was very careful to ensure I had the hole-ID letters correspond upper with lower, and there aren't many orientations that allow this as the back of the board also letters left to right. working without those references as placement aids would be an unnecessary extra layer of difficulty.

[duck_arse]

last week I thought a big muff was too difficult for cordwood. last night I saw this pic:



today I was thinking about phasers and things, but crossed them off because of feedback resistors (since then I see it is more doable if the IC is mounted on the top-outer and top-soldered, so the holes under/between the IC pins could be used as well). and then I thought about the BC847B smd transistors I have, and the way the collector lead is the other side of the body to the base lead, and how they could then be strung C to upper and B to lower, and all those B-C interconnects on the muff become no problem. and an upper-board radial cap from C to diodes makes it even neater. [there is no reason the collector need go uppermost, whatever orientation gets you there would do - and there are quite a few different orientations possible.]

later still I was thinking of what all else could be built, and thought of vactrols. with an oscillator and flashing led on the lower board, and the whatever audio section on an upper board, we can get proper supply separation and direct in-line opto mountings and all sorts of other benefits. PLUS imagine how good the whole thing will look with led light flashings coming from deep within.

I feel another magnavibe layout in the offing. I need to get out more.

does anyone have any other ideas for possible builds? moosetone?

[rutabaga bob]

Be careful...your cordwood is smoldering...

[EBK]

last week I thought a big muff was too difficult for cordwood. last night I saw this pic:



today I was thinking about phasers and things, but crossed them off because of feedback resistors (since then I see it is more doable if the IC is mounted on the top-outer and top-soldered, so the holes under/between the IC pins could be used as well). and then I thought about the BC847B smd transistors I have, and the way the collector lead is the other side of the body to the base lead, and how they could then be strung C to upper and B to lower, and all those B-C interconnects on the muff become no problem. and an upper-board radial cap from C to diodes makes it even neater. [there is no reason the collector need go uppermost, whatever orientation gets you there would do - and there are quite a few different orientations possible.]

later still I was thinking of what all else could be built, and thought of vactrols. with an oscillator and flashing led on the lower board, and the whatever audio section on an upper board, we can get proper supply separation and direct in-line opto mountings and all sorts of other benefits. PLUS imagine how good the whole thing will look with led light flashings coming from deep within.

I feel another magnavibe layout in the offing. I need to get out more.

does anyone have any other ideas for possible builds? moosetone?

I love the beautiful irony of a surface mount cordwood design.  Would be neat if you exclusively used SMDs with wires attached. 

[287m]

silly question
- smd transistor not heat sensitive? never try smd before
- are axial elektro caps is MUST in cordwood?
- any example cordwood with op-amp?
Thanks

[duck_arse]

silly answers:

smd yes heat sensitive, but no more so than ordinary thru holes. get in and out fast, no probs.
axial electros are not MUST, no. neither axial poly's. but in the spirit of the method, and because they make the layout sensible. use what you have/what you can get/what you can fit.
there are VERY FEW examples at all at the moment. I've only just decided opamp might be doable today.

what's on your mind?

[digi2t]

People...

If I can get away with this...



then I don't think cheating with cordwood will be a problem. 

Of course, you could always go with a canned op amp,



and work around it. Maybe start with it in the middle, and work your way out from it.

[PRR]

> smd transistor not heat sensitive?

I have abused a through-hole power transistor so bad that it was working even though the solder on its legs was melted (I noticed it flopped in its holes). That's probably bad for long life, but not instant-death.

SMD parts are mass-soldered by solder-dip. The end page of the datasheet (or another sheet) tells the time and temperature allowed for "full function and reliability". Generally you can spend a few seconds at full molten solder temperature. Doing 3-leg parts by hand, you should be able to get on and off each leg that quick.

The full dip-solder specs also show pre-heat and cool-down times. I believe the pre-heat is less important with an iron than with a dip: the iron tip will not instantly bring the leg up to temp like a ton of solder will. I think the cool-down spec relates to an air-jet used to remove excess solder after dip-solder; if too violent there is thermal shock you can't get in hand soldering.

I think you can cook modern Silicon devices many minutes at hot iron temperature and they will work the rest of your life. However there is NO point in prolonged heat. Your technique (including flux) should allow very rapid (couple seconds) heat/cool and good joints.

Doing all three legs by hand, I would wait a few seconds between each joint, though that may not be essential. Doing an 8-DIP I would probably do a couple legs, stretch my arms, a couple more, stretch my back, so heat did not build up.

[EBK]

I have abused a through-hole power transistor so bad that it was working even though the solder on its legs was melted (I noticed it flopped in its holes).

...

...

That's much worse than watching Bambi on the first day of deer season! (true story from my childhood, btw   )

[duck_arse]

I have today finished a layout diagram for a doctor boogie, or near equivalent. it is in this buckett, with a circuit diagram. (even tho it has been scaled, it is still a very large image. also quite difficult to understand, I think.)

http://imgur.com/a/c8Uqj

I'm just waiting on the okey-dokey from bluebunny, who is carefully checking the layout for me, and then I'll start soldering. I'll update the buckket w/ pictures as I go.

[bluebunny]

Aagh!  My eyes!  Please drop experimental cosmetics into them instead!

[rutabaga bob]

You forgot to wear your protective goggles!!!

[duck_arse]

finished. der bootie. more photos tomorrow.

[Kipper4]

Bloody hell. Didn't realise you actually intended to build a circuit like it.
I thought it was just a graphic thing

What size box.

Nice work Duck.