show us your ugly but flawless project  - Page 1
Forum section: electronics / general

author: hussamaldean
author_rank: Unknown
timestamp: October 31, 2018, 12:30:21 pm
content: Hi allI want you share with us your ugly project but function flawlesslyhere I amI did it like a year ago

author: Cyberdragon
author_rank: Super Contributor
timestamp: October 31, 2018, 04:50:02 pm
content: How do we know it works?You have proven nothing! Show us your voltages!

author: hussamaldean
author_rank: Unknown
timestamp: October 31, 2018, 05:53:06 pm
content: Quote from: Cyberdragon on October 31, 2018, 04:50:02 pmit does work because I've just used it for op-amp experiment

author: KrudyZ
author_rank: Frequent Contributor
timestamp: October 31, 2018, 06:05:06 pm
content: What's on the inside?Or is it too pretty to show in this thread?

author: hussamaldean
author_rank: Unknown
timestamp: October 31, 2018, 06:14:46 pm
content: Quote from: KrudyZ on October 31, 2018, 06:05:06 pmit is so pretty that it is so shy to show itself

author: m98
author_rank: Frequent Contributor
timestamp: October 31, 2018, 08:07:23 pm
content: Wow, what's that?

author: capt bullshot
author_rank: Super Contributor
timestamp: October 31, 2018, 08:10:12 pm
content: All my projects are ugly and of course flawless

author: MrW0lf
author_rank: Frequent Contributor
timestamp: October 31, 2018, 08:21:45 pm
content: Quote from: m98 on October 31, 2018, 08:07:23 pmIt was a time when I could do pulse motor from dead dingos dongerIt has reed switch, flyback diode, coil with core from bolt. Rotor is broken HDD with some magnets stuck to it. Hand picked materials to suppress eddy currents etc. Worked just fine connected to wall wart. In short - was visiting friend with some beers and asked what components do you have I wanna make a pulse motor NOW

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 31, 2018, 11:59:42 pm
content: I added a second NIC to a Pogoplug to make it a router. Even though the PCIe wiring wasn't done in the best way, it passed days of stability testing and has been in service at a relative's place for a few years.

author: Circlotron
author_rank: Super Contributor
timestamp: November 01, 2018, 12:08:26 am
content: Quote from: NiHaoMike on October 31, 2018, 11:59:42 pmThat's what I imagine Windows 10 source code to look like.

author: bsfeechannel
author_rank: Super Contributor
timestamp: November 01, 2018, 04:23:12 am
content: Wien bridge oscillator (None of this arbgen rubbish!). 20Hz ~ 20KHz, in three ranges. 20Vpp with a x10, x100 attenuator. 600output impedance. Based on a modern version by Jim Williams of the legendary HP200A. There is a provision for a square wave based on the design of other HP oscillators but I haven't implemented it yet.Ugly as frig. Works a treat.

author: hussamaldean
author_rank: Unknown
timestamp: November 01, 2018, 05:57:38 am
content: Quote from: capt bullshot on October 31, 2018, 08:10:12 pmthis is how boss rules

author: hussamaldean
author_rank: Unknown
timestamp: November 01, 2018, 06:01:18 am
content: Quote from: bsfeechannel on November 01, 2018, 04:23:12 amor you should saynot of this PCB rubbish

author: Whales
author_rank: Super Contributor
timestamp: November 01, 2018, 07:43:41 am
content: Quote from: bsfeechannel on November 01, 2018, 04:23:12 amWhat? What's not ugly at all. Get out of this thread!EDIT: First few seconds of this:

author: Wolfgang
author_rank: Super Contributor
timestamp: November 01, 2018, 10:53:37 am
content: Hi,I have a whole page of ugly stuff if someone is interested:https://electronicprojectsforfun.wordpress.com/prototyping/long live the Bronx construction style. Manhattan is for sissies

author: firehopper
author_rank: Frequent Contributor
timestamp: November 01, 2018, 03:49:48 pm
content: How about thishttps://www.flickr.com/photos/firehopper/albums/72157700957050681my 100 watt flashlight build, its kinda fugly I guess.. not quite finished yet, have to figure out why the fan keeps stalling when its installed.. I suspect wires getting in the way.

author: bsfeechannel
author_rank: Super Contributor
timestamp: November 02, 2018, 06:44:47 am
content: Quote from: Wolfgang on November 01, 2018, 10:53:37 amDo prototypes count? I thought only "final" products were allowed.

author: Dubbie
author_rank: Unknown
timestamp: November 02, 2018, 06:58:48 am
content: Wolfgang, I like your work!

author: Wolfgang
author_rank: Super Contributor
timestamp: November 02, 2018, 09:57:47 am
content: Quote from: bsfeechannel on November 02, 2018, 06:44:47 amI have to admit that some of my stuff never made it into "production"

author: Wolfgang
author_rank: Super Contributor
timestamp: November 02, 2018, 10:23:11 am
content: Quote from: Dubbie on November 02, 2018, 06:58:48 amThanks, Dubbie ! Having fun is the best reason to fiddle with tech stuff !

author: MrW0lf
author_rank: Frequent Contributor
timestamp: November 02, 2018, 10:38:42 am
content: Quote from: MrW0lf on October 31, 2018, 08:21:45 pmForgot crucial detail that makes it flawless! Notice that weird blob taped to fork? It's a magnet to pre-bias reed switch

author: bsfeechannel
author_rank: Super Contributor
timestamp: November 02, 2018, 10:17:27 pm
content: Quote from: Whales on November 01, 2018, 07:43:41 amI'll take that as a compliment.You haven't seen the underside of the board.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 03, 2018, 01:04:22 am
content: I'll go for a twofer.Pretty but flawed:Lead acid battery charger, almost 200W (nominal 100W, but it limits closer to 200, who's counting?).Pretty: PCB; enclosure; printed label; SMPS; the transformer is wound on a proper bobbin, with proper yellow polyester tape; EMI is quite low (extra filters in the enclosure, besides what's on the board).Flaws: resistors, diodes and capacitors tack-soldered onto flying leads (the TO-220F is a snubber diode, formerly a UF5406 that desoldered itself; plopping in an SiC schottky shut it up!); the LED wires lack strain relief; the fan (and output side LED) is powered from a series dropping resistor from the output, so it's parasite-powered when left wired to the battery; etc.Ugly but flawless:Ugly: just look at it. It's been sitting out on the project pile for years, neglected. It's a mashup of PCB and deadbug construction.Flawless: it's a textbook example of the circuits used (and not in a bad way), it's efficient, it works great, and it's not very noisy (I wouldn't say silent, but more filtering can be added if that turns out to be necessary). At least, last I recall from working on the project, again it's been a while. Though, I may run out of available supply current once I build the next section, which would then be a pretty clear flaw. Not sure.Why is it a mashup? What the heck is it?It's the power supply to my old tube scope project. So, rough specs:120VAC inputCRT filament: 6.3V 0.6A (HF AC), HV isolatedCRT cathode and bias: -2000V 1mA, zener regulatedHeaters: 6.3V 10AB+, B-: +/-250V 100mASo, a bit over 100W total (maybe 2-3A mains fuse would be adequate).The original circuit dating from 2010 was a forward converter,https://www.seventransistorlabs.com/Images/Tubescope_Supply2.pngwhich I underestimated the transformer size required to pack in all the windings (at adequate wire ampacity plus room to keep the HV windings' impedance high). Result, nasty overshoot on the HF windings. The UF4007 melted right away. Take two, doubled up diodes (two UF4007 in series for each diode shown). Better, but one diode always got meltingly hot -- reverse recovery loss is always a runaway condition, it's just a matter of keeping temperature low enough that it doesn't actually tip over. These... weren't. Take three: with 5.6k (1W) + 100p dampers in parallel with each diode pair. Helped reduce the peak voltage, but burned a lot of power, and the diodes still weren't feeling it. (You can try to mitigate a bad transformer, but there's only one solution to the reactive power stored in its parasitic capacitance and stray inductance, and that is: not storing it in the first place.)And yes, that was built on a hand made, single side PCB. The biggest I had made to that point (4 x 8 inches), and on the only PCB stock I had at the time, which was embarrassingly thin. So this big heavy power supply was also very floppy, out of its mounting bracket...Much later, I picked up the project again, saidfuck it, and literally cut the board in two, saving only the resonant HV circuit and mains rectifier and filter circuit. With new PCB stock in hand, and a newly learned fondness for deadbug, I built a UC3843 based flyback supply, as basic as can be. STW11NM80 switch (which I had a few leftover/salvaged from an earlier induction heater project), and learning lessons not just from the previous disaster transformer but also general design lessons (TLT theory is the most general and helpful approach), I designed the transformer windup so that no* common mode voltage appears between single-layer windings, giving maximum bandwidth -- sharp edges, so that when the transistor turns off, the secondary diodes catch almost instantly, without current flowing through common mode capacitance, bouncing around winding wire lengths.*Still some, but only due to leakage, not the whole winding voltage.And this worked great, except it had a tendency to 1. overheat the HV rectifier diodes anyway, and 2. run away and flame out the transistor.Which was also fun for a secondary reason: the fuse took so long to clear (allowing the transistor to flame out, not just pop) because of the high impedance of the isolation transformer I was working on. The lesson being: higher available fault current can actually be safer, when fuses are involved. Limiting current to a low value, where a fuse may not blow at all, is rather more dangerous than leaving it unlimited!So for my final step, I added a TC4420at the gateto drive the shit out of the transistor, and a dV/dt snubber to ensure controlled commutation time and ringing. I also changed the HV diodes to SiC schottky, which despite their higher capacitance (mainly at low voltages, which looks very much like reverse recovery, but over a wider voltage range, and which isn't lossy), have far lower losses, and better dynamics (less ringing). Recovery really is just that much of a problem, even on fast recovery (~30ns) types.Also you'll note, the HV filter caps are film (8.2uF 250V PE), mainly because I happened to have a bunch on hand, but they filter nicely, too.Tim

author: KE5FX
author_rank: Super Contributor
timestamp: November 03, 2018, 09:35:56 pm
content: Quote from: T3sl4co1l on November 03, 2018, 01:04:22 amWhat's TLT theory?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 03, 2018, 10:27:12 pm
content: Transmission line transformers, using the principle that any two wires more or less travelling in parallel make a transmission line, of impedance determined by the geometry and that impedance being suited to the circuit (not necessarily matched, as the case may be). The low frequency consequence is minimal Cp and LL for a given design.Tim

author: Red Squirrel
author_rank: Super Contributor
timestamp: November 04, 2018, 04:04:11 am
content: Monitored mouse traps:It's ugly in the sense that it looks like some kind of torture device, but it's really just a dry contact which uses foil strips with magnets to hold in place. When mouse trap trips it dislodges or breaks the strip which breaks the circuit which triggers an alarm condition. There's 3 alarm points, the 2 traps in a single alarm point are in series.The old version used the actual trap for the conductor but it proved to be flawed as it corroded over time and I'd start to get false positives as resistance was very high.Which reminds me, I should go up in the attic and reset the two that are tripped (been like a year lol) and also add fresh peanut butter. I really need to figure out how they're getting in in first place though, but it's hard to figure out when I only get like 1-2 per year.

author: Martin.M
author_rank: Frequent Contributor
timestamp: November 04, 2018, 05:34:28 pm
content: my tube amplifierwith international parts , including CCCP, USA, China and germany

author: Gyro
author_rank: Super Contributor
timestamp: November 04, 2018, 07:12:20 pm
content: Pah, mine's uglier though!...and at one point it was uglier still (with Darwin award possibilities)!P.S. Your's is quite a work of art - I like the ground bus. Care to compare top views?

author: David Hess
author_rank: Super Contributor
timestamp: November 06, 2018, 02:50:15 am
content: This is an RF level detector which requires only one hand to operate and is intended for locating hidden transmitters at close range; close range includes "which leaf or rock is the transmitting antenna". With a short loaded 1/4 wave antenna attached, it can located transmitters between less than 1 milliwatt and more than 10s of watts. Feedback is via an audio tone which doubles in frequency for every 6dB increase in signal strength so when the tone doubles, half the distance to the transmitter has been covered. (1) Operating frequency range is HF to beyond UHF.An automatic gain control circuit limits the peak audio tone to about 1kHz and remembers that gain so the only control is the pushbutton switch shown which "resets" the gain. This simplified interface allow one handed operation by hearing which frees the eyes to visually search and the other hand to hold a flashlight. The automatic gain control uses a 2N7000 as a variable resistor with trimmable drain to source feedback to control the octave/dB transfer function. The 0.1uF film capacitor shown remembers the peak gain control setting.An LT1007 provides almost all of the gain after detection. An earlier design I did based on theone published by K0OVused a chopper stabilized amplifier for greater gain and less drift but this created problems due to slow overload recovery.The RF detector was originally a pair of matched 1N4148s in a biased square law detector bridge but later I changed it to a simpler full wave rectifier using 1N270s which worked just as well if not better. If I did it again, I would revisit the temperature compensated square law detector bridge and maybe use chopping and transistor base-emitter junctions instead of diodes. (2) The ultimate sensitivity is better than -60dBm which is much more than can be used in the field without a narrow RF preselector.(1) An earlier implementation produced an audio tone like a Geiger counter. This was not only more difficult to use but was found to alarm the general public resulting in law enforcement being summoned.(2) Schottky detector diodes would be the obvious choice however they are easily damaged with overload and the sensitivity is already much better than needed.

author: BrianHG
author_rank: Super Contributor
timestamp: November 06, 2018, 04:06:19 am
content: Ohhh why didn't this forum, subject topic and cheap digital camera's exist 20 years ago. I would have supplied my home made works of art... 200 watt stereo amp in a box, 50 watt amp on a plank of wood, 3d glasses, power supplies, 3d glasses, stationary bike generator, and the list goes on. But, one photo I've kept, only around a few years old, is a natural gas hot water tank, where the natural gas was disconnected, so, I used a 120v plug in fan heater feeding the base to make hot water and it worked for a year straight making enough hot water for showers and doing dishes for 2 people during the summer, 1 or 2 people being conservative in the winter, take a look: (The heater was running 24/7 on it's low/half power mode) And yes, I'm crazy! (There was NO natural gas service to the house!, nothing in the pipes, I'm not that dumb...) Yes, that tinfoil is multiple layers thick to the point that you might be able to call it duct grade & after 1.5year of use, once dismantling, there was a brown darkened spot on the lower right of the heater's heating element.Through those 2 previous winters, I saved around 800$ total since natural gas here in Quebec now costs twice as much as heating with just normal baseboard heaters, not to mention if you have a heat-pump for the rest of the house...

author: Circlotron
author_rank: Super Contributor
timestamp: November 06, 2018, 06:12:57 am
content: My shot at a soft starter and power saver for a 3-phase induction motor, early 1988. Instead of measuring motor load by power factor, it measured load by actual motor rpm with a Hall effect sensor and a single magnet glued to one of the fan blades. In this particular example the full load rpm of the motor was 1440 and no load 1500. The board phase controlled 3 anti-parallel SCRs and if the motor was running faster than full load speed it would back off the voltage till it got back down to that speed. Applied voltage was proportional to load. At no load it reduced the power drain to 1/6th, and rather less as the load increased. DIP switches at the end of the board set the motor full load rpm. 102 CMOS ICs and my first time laying out a board with more than 1 or 2 ICs, first time using Protel 3.08 and first time actually using a PC.(XT) Entire circuit drawn on a huge piece of paper and traced out onto the screen, pad to pad. No schematic on the screen, no netlist showing the connections, no internet to ask questions. Took 2 weeks and it worked! Only 1 or 2 minor board routing mistakes. Made 1 unit and demo'd it to the boss and then the company ran out of money and closed up. Ahhh.... to be 30 yo again and know what I know now.

author: BrianHG
author_rank: Super Contributor
timestamp: November 06, 2018, 08:05:47 am
content: Quote from: Circlotron on November 06, 2018, 06:12:57 amWow!, and this coming from a guy who has seen a 68040 accelerator for the Amiga 2000 with 32mb of ram done as a wire-wrapped functioning prototype and I personally designed and made a true 24bit RGB video card for the Amiga on a breadboard with ram ICs piggybacked on top of each other...

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 06, 2018, 10:42:39 am
content: Looks just like any of the industrial logic boards I've seen over the years.Tim

author: Cyberdragon
author_rank: Super Contributor
timestamp: November 06, 2018, 08:05:40 pm
content: Quote from: Martin.M on November 04, 2018, 05:34:28 pmHow dare you, that is pretty!Remove the terminal strips to reach ugly status.QuoteEEEEEEEEWWW!(must have stinked up the place)

author: Wan Huang Luo
author_rank: Regular Contributor
timestamp: November 09, 2018, 04:35:10 pm
content: Quote from: Circlotron on November 06, 2018, 06:12:57 amI design soft starters for a living.So, um..Hmm.I thoroughly commend the results of the work you've done!Quote from: BrianHG on November 06, 2018, 08:05:47 amThat's also impressive work. The extent of my 68040 experience is taking a 25mhz mc68rc040 and putting it in the place of a 25mhz 68LC040. Then overclocking it to 40mhz by moving some smts around and putting a heatsink on top. Nothing like designing a video card! I humbly bow to you too.

author: lordvader88
author_rank: Frequent Contributor
timestamp: November 10, 2018, 04:35:10 am
content: I need to get a camera working

author: bsfeechannel
author_rank: Super Contributor
timestamp: November 10, 2018, 03:48:16 pm
content: Ugly is the new beautiful.

author: Wolfgang
author_rank: Super Contributor
timestamp: November 10, 2018, 04:26:12 pm
content: ... and dumb is the new smart.

author: Wan Huang Luo
author_rank: Regular Contributor
timestamp: November 10, 2018, 04:34:49 pm
content: Quote from: Wolfgang on November 10, 2018, 04:26:12 pmBut please tell me how a Wolfgang is different from a Wolfpack?

author: ledtester
author_rank: Super Contributor
timestamp: November 11, 2018, 06:05:02 am
content: Not my own, but a Bob Pease design:

author: Wolfgang
author_rank: Super Contributor
timestamp: November 11, 2018, 11:51:50 am
content: Quote from: Wan Huang Luo on November 10, 2018, 04:34:49 pmNo idea. I was socialized in the dark ages of Monty Python and Alfred E. Neuman