throbscottle

145
Loving getting back into electronics as a hobby after a break of many years. Now I work as an EPOS engineer, so I spend my days fixing tills in shops and restaurants, and it feels like I'm doing something I'm actually good at for a living instead of trying to do things I'm not good at! I like to turn my hands to all sorts of things - woodworking, engineering, sewing, cooking, even leatherwork! I occasionally write bad poetry and stories too. But I think I'm best at repairing stuff.

Achievements

100+ Comments Earned a bronze medal
10K+ Views Earned a bronze medal
• throbscottle commented on wordsnwood's instructable Electric Sofa Table5 days ago

The end of my sofa is a riot of cables, a rough table with a shelf, and a vertical socket extension. You have certainly given me food for thought as to a better way....

• throbscottle commented on 陳亮's instructable Select Color Display for ESP3210 days ago

Thanks for an informative instructable!I'm wanting to connect a VGA camera, the sort you find as a little module on eBay with OVPxxxx chip, to a screen such as ILxxxx family, which appears to have direct VGA input. I think it will work if I connect the camera directly with no MCU, but I'd also like to add a cross-hair to the display (for a drill targetting system). I wonder is it possible to intercept the serial video data and change individual pixels in a streaming fashion, instead of loading a whole screen into memory, changing it and passing it on? I ask because it seems to me it would need a much less powerful MCU.

• Hi thereThe circuit relies on Ohm's law, which states that the voltage across a resistance is directly proportional to the current passing through it. I assume you are familiar with V=I*R.Perhaps you are less familiar with op-amps, in which case, briefly, (in a linear (ie, normal) feedback scenario) the output voltage of an op-amp is directly proportional to the voltage at it's non-inverting input, or inversely proportional to the voltage at it's inverting input. If the op-amp doesn't have some negative feedback the output will try to go to either supply rail with even the tiniest difference in input voltages. With feedback, it will always changed it's output to try and make it's inputs equal.The mosfet transistor is there to provide a substantial current path for the load. You needn't ...

see more »

Hi thereThe circuit relies on Ohm's law, which states that the voltage across a resistance is directly proportional to the current passing through it. I assume you are familiar with V=I*R.Perhaps you are less familiar with op-amps, in which case, briefly, (in a linear (ie, normal) feedback scenario) the output voltage of an op-amp is directly proportional to the voltage at it's non-inverting input, or inversely proportional to the voltage at it's inverting input. If the op-amp doesn't have some negative feedback the output will try to go to either supply rail with even the tiniest difference in input voltages. With feedback, it will always changed it's output to try and make it's inputs equal.The mosfet transistor is there to provide a substantial current path for the load. You needn't worry about it's inner workings. An increase in voltage on it's gate results in an increase in the current flowing between it's drain and source (this is called transimpedance).Resistor R2 is to prevent some effects which can occur due to the gate capacitance of the mosfet.The first op-amp, U1a, exists solely as a buffer (ie, it has 100% negative feedback resulting in unity gain) for the potentiometer, it's only being used here because it's a dual op-amp package and it's better to connect it into the circuit. Only 1 of the op-amps is shown with power connected because there is only one set of power pins between the 2 of them.The two diodes in series act as a voltage reference. The exact voltage isn't important, though it would be better with a more stable reference. The potential divider which includes the potentiometer is arranged so that the maximum voltage available corresponds to the voltage which will appear across R3 at the maximum current of interest.So, you set the potentiometer to some value, and connect a power source across the terminals Conn1 and Conn2. Current will flow, and if enough current is available from the source, a voltage will appear across R3 which is equal to the voltage you set. Remember the op-amp tries to make it's inputs be at equal voltages, so at this point it's happy. Any more current flowing through the the mosfet and R3 however, will result in a higher voltage being applied to the inverting input than the voltage you set, so the op-amp will reduce it's output voltage, which in turn will reduce the current flowing, causing the feedback voltage to also reduce. So again it's happy. The converse is true if the current through the mosfet and R3 should reduce for any reason: the voltage across R3 will also reduce, so the op-amp will try to make it go up again by adjusting it's output upwards.

• throbscottle commented on tonyfoale's instructable Manual Thread Tapping Machine25 days ago

So impressive! I didn't even know such a thing existed. Just what I need for the occasional small hole. Don't think improvised tooling would be up to making the full sized version. Maybe I could make a sleeve + stand for my mini-tap holder. Voted, anyway :)

• throbscottle commented on Wonder Tech's instructable DIY PCB Drill Press Machine4 weeks ago

Sometimes the simple methods are the best! Very helpful - thank you :)

• throbscottle commented on Wonder Tech's instructable DIY PCB Drill Press Machine5 weeks ago

Thanks for the response. Yes, exactly that.

• Slight pick-up on your terminology:"debouncing problems"="switch bounce" or just "bounce" if it's clear from the context that a switch is being referred to.Nice project, it's really good to see someone making something with logic chips instead of reaching for a microcntroller for every little thing. Well done!

• throbscottle commented on Wonder Tech's instructable DIY PCB Drill Press Machine6 weeks ago

How did you attach the head to the the cd/dvd mechanism? I ask because I started making a similar machine years ago but didn't finish it. This was one of the problems I encountered.

• throbscottle followed Electronics, Reuse and Linux channel 7 weeks ago
• Hi Jenyz. Please see other answer regarding components on the solder side. I hope it makes sense! With regards to having more ground vias on the solder side, I suggest these go only part way through the board and connect to an inner layer. I wish I could provide a way to map inner layers but unfortunately the methods (see discussion in the comments) are to X-ray the board or destroy it, neither of which I imagine you want to do. However as they are ground-plane vias at least you know it is a ground layer they are connecting to.Good luck!

Hi Jenyz. It's a very long time now since I did this so I have forgotten much, however looking back over it I would suggest you use the methods shown from steps 13 to 15 on the solder side, which will leave you with just the tracks, and then go back to the earlier steps to process them as if there were no components, and then jump back to step 16. With the image of the components you made from the solder side, I suggest you add these as per step 17, then turn off the layer with those components on it, then repeat step 17 for the components on the component side.Good luck with your project!

• throbscottle commented on kweixelman's instructable Rivet Block2 months ago

Voted!

• throbscottle commented on ClenseYourPallet's instructable Pliers Organizer Thingy2 months ago

Hmm, I like the dividers though. I'll think of something. Thanks for the compliment, though to be honest it looks better than it works! Needs a better design and more conductive/toughter electrodes.

• Step 3 produces the clean images which you use for the subsequent steps. My apologies for not making that clear.

• throbscottle commented on ClenseYourPallet's instructable Pliers Organizer Thingy2 months ago

Better yet, have a slide out tray-for-catching-dropped-things.

Sorry I don't know what is meant by "skill saw". I only have hand tools + drills.

I might have a go at this, it would take rivet gun and tin snips and teeny tiny pliers too. But what's a good simple way to slot in the dividers without a cross-cut or table saw being available?

• Perhaps it is time for the Wire Wrap Renaissance! It's definitely something to consider doing - sometimes solder joints or pin connectors aren't quite what's needed.Some things I noticed compared to what little I know about wire-wrapping:1) I'm pretty sure the proper method of wire wrapping requires 2 or 3 turns of the insulated portion of the wire to be wrapped, which acts as a strain relief - also stops bare wire coming directly from the joint2) Wire wrap pins aren't like the headers you get nowadays. They have sharp corners which bite into the wire, which header pins don't have. These sharp corners are the secret of it making an extremely reliable connection..

• I'm pretty sure this was addressed in another HDPE recycling instructable. Apparently HDPE doesn't give off fumes at the temperature used.

I'm surprised you haven't made a wooden cylinder instead of a disc for pressing down inside the can. It would eliminate the tilting problem.Beautiful work. Well done!

• Very clever. I'd be worried about accidentally trying to write with it! Don't worry too much about using the correct word - scribe or scriber, engineering people know what you mean!

• throbscottle commented on schnurrbart's instructable Custom Handmade Screwdriver2 months ago

i have a screwdriver that needs a new handle so I might have a go at this. Just need to figure out how to make a tailstock for my botched-together "lathe"...Beautiful work. Well done :)

• Comic fantasy mostly, also tried his hand at books for older children and science fiction, but best known and loved for the Discworld novels, a magical flat world carried on the backs of 4 elephants, who in turn stand on the back of Great A'Tuin, a space faring turtle, orbited by a tiny sun, permeated by magic. As his career went on they improved from a literature point of view but became less comic and the fantasy became more refined. He doesn't write now unless they have typewriters in heaven. RIP TP, a very great and sad loss to us all. 1st book, The Colour of Magic, last book, I Shall Wear Midnight, and many brilliant novels in between

• throbscottle commented on M8377's instructable Nixie Tube Watch3 months ago

Completely bonkers. I love it!

• throbscottle commented on fretters's instructable Computer Drawer4 months ago

Vey clever. I like how you even made it fit around the table leg!

Hard drives are tougher than you think. They will stand quite a lot indirect abuse!

• throbscottle commented on sbkirby's instructable Drill Press Laser Guide4 months ago

Very clever using 2 lasers so cross is correct position at any table height.I tried to make one of these for my PCB drill using a crosshair laser but of course it suffered from the exact problem of work-piece height (also laser beam can't be focussed fine enough for sub 1mm drills!)Hats off to you!

• throbscottle commented on videoschmideo's instructable Make Circuit Boards With Lasers4 months ago

It's one piece of information I always try to share, having been caused wasted hours + materials myself by it. Acetone is great for cleaning off all kinds of stuff, but for that one caveat.

• throbscottle commented on seanhodgins's instructable Addressable 7-Segment Displays4 months ago

Really clever, but without your invention 4 displays would take 11 lines, not 28! (well actually 12 because you have the decimal point) due to multiplexing.Clever making individually addressable digits. The other way to do it is with a driver chip like the (now obsolete) MAX7219 or 7221 but the chip stays connected to the uC via a 4 wire interface. The displays themselves are still multiplexed but otherwise you have similar control.

• throbscottle commented on videoschmideo's instructable Make Circuit Boards With Lasers4 months ago

Clever technique for those with a laser cutter, quite an impressive idea.Heads up about acetone though, it can actually leave a greasy residue, which is not good for making paint stick. Better to clean again with alcohol after the acetone. Better yet to follow full PCB cleaning procedure, more hassle but you do get a decent surface.

• throbscottle commented on ImpactDIY's instructable Steampunk Flashlight How to Make4 months ago

Nice torch but it's a shame you cut the legs off that "magic eye" valve for it! A bit more work (well ok a lot more work) and you could have got the magic eye to light up in the side window and indicate temperature or your heartbeat or something. But that would eat up the battery and make the torch pretty hot to hold too but hey!

• throbscottle commented on Techgenie's instructable How to Make Remote Control Scorpion4 months ago

I just love this. Something to do with some of those old motors I have sitting around!I have stripped the guts (for parts) from so many old mice and thrown the cases - I wish I'd kept the cases now! Maybe I can still find one...I particularly like the way the ridges in the cardboard give the body parts a more natural look than if they were just smooth. Really good.

• I have voted for this, I think it is pretty good for a first instructable! One thing I would suggest though, is put more than just fig 1 fig 2 etc in the picture comments. It's much easier for your readers if you put a little explanation in there of what each picture is showing.I'm quite inspired to actually try building this. There isn't anything I can't afford and there isn't anything I'm unable to make! So it's right up my street!

• throbscottle commented on Palingenesis's instructable Tim's PCB (Plotted Circuit Board)5 months ago

This is very very clever. An X-Y plotter is out of reach for most of us though.But you got me thinking about how a Scan'N'Cut machine could be used to similar effect (since my wife has one). I think you could use it's pen holder with a resist pen to draw on plain board stock, and then on the component side with a fine marker to draw the component locations. I wouldn't want to try getting it to drill though!

• throbscottle commented on Tuomas Soikkeli's instructable Welders Third... Clamp Thingy.5 months ago

A few weeks ago I did my first welding since near 30 years past. Wow, what fun and games I had there! (I actually welded T pieces to the heads of some bolts)But it would have been so much better if I'd had these handy clamps! They are exactly what I needed!So when I dig the welder out again, these will be the first thing I make :)

• throbscottle commented on JavierL90's instructable Lissajous Curve Apparatus5 months ago

Very amazing, I am suitably impressed!It occurs to me you could fit the laser itself with a lens and then be able to magnify the image. Get the focus right and the beam should be able to end up whatever diameter you want. Just a thought, might be rubbish, I don't pretend to know!

• It's really great to see someone has come up with an acid/peroxide etchant using easily available and cheap white vinegar, instead of expensive and hard to obtain hydrochloric acid. Nice tip with the sticker backing paper there too!I'm surprised the etchant is only good for one board - the versions I have read about using hcl and peroxide will etch many boards - since this is similar stuff will it not do the same?I'd like to raise a couple of caveats if I may, lessons I learned early on:Acetone can contain dissolved grease, which can end up being left as a residue on the thing you are trying to clean. I found this out the hard way and wasted many hours. Fine aluminium oxide paper (around 400 grit) and water and a tiny bit of detergent works really well for cleaning. Isopropanol is usefu...

see more »

It's really great to see someone has come up with an acid/peroxide etchant using easily available and cheap white vinegar, instead of expensive and hard to obtain hydrochloric acid. Nice tip with the sticker backing paper there too!I'm surprised the etchant is only good for one board - the versions I have read about using hcl and peroxide will etch many boards - since this is similar stuff will it not do the same?I'd like to raise a couple of caveats if I may, lessons I learned early on:Acetone can contain dissolved grease, which can end up being left as a residue on the thing you are trying to clean. I found this out the hard way and wasted many hours. Fine aluminium oxide paper (around 400 grit) and water and a tiny bit of detergent works really well for cleaning. Isopropanol is useful too.The highest temperature of your iron will be too hot for a lot of people, causing the toner to turn runny and make wobbly edges. I would suggest experimenting and using the lowest temperature that will fuse the toner to the board, no more.

• throbscottle commented on osgeld's instructable Put Your SMD Parts on Standard Perfboard6 months ago

Nice work!But I would recommend using magnet wire for your connections as then you don't have to worry about stripping off the insulation (unless you are unlucky enough to get the Plain Old Enamel sort) it is polyurethane which just melts away with the heat of your soldering iron!I'm using 0.1mm wire at the moment (because it was cheap). It's a bit on the thin side though! Here's an extreme example: https://www.youtube.com/watch?v=i5MNLTc7YhY (and someone has made an instructable on how to make a wiring pen like that).

• You can actually do a better calculation by looking at the relay's data sheet. They all specify an an operate voltage and release voltage (sometimes current is given instead) so if you look at the data-sheet for OSA-SS-205DM3,000 for example, which has a 5v, 47 ohm coil, you see the operate voltage is actually 3.75v and the release voltage is 0.25v. So your resistor only needs to allow the coil to be over 0.25v! I'd go for 1v to be safe, so assuming you have a 5v supply you get 1/47=0.0213, 5-1=4, 4/0.0213=187.79, so nearest value is 180 ohms. The resistor power is given by V^2/R, V is still very close to 4, so 4*4/180 gives 0.09W, so only a tiny sized resistor is needed . To get the capacitor (without doing really heavy maths) you need to know the pull in time of the relay. At full pow...

see more »

You can actually do a better calculation by looking at the relay's data sheet. They all specify an an operate voltage and release voltage (sometimes current is given instead) so if you look at the data-sheet for OSA-SS-205DM3,000 for example, which has a 5v, 47 ohm coil, you see the operate voltage is actually 3.75v and the release voltage is 0.25v. So your resistor only needs to allow the coil to be over 0.25v! I'd go for 1v to be safe, so assuming you have a 5v supply you get 1/47=0.0213, 5-1=4, 4/0.0213=187.79, so nearest value is 180 ohms. The resistor power is given by V^2/R, V is still very close to 4, so 4*4/180 gives 0.09W, so only a tiny sized resistor is needed . To get the capacitor (without doing really heavy maths) you need to know the pull in time of the relay. At full power (532mW) this is 7mS, but since the pull in current is going to be falling, allow a bit more, the coil power at 3.75v is 3.75x3.75/47=300mW, which gives 9mS. You can judge how much the capacitor can charge by going by the operate voltage - don't go below this value. Use an on-line calculator to determine what capacitor will charge to 5-3.75=1.25v in 9mS through a 47 ohm resistor (the coil), to save doing heavy maths: http://mustcalculate.com/electronics/capacitorchar... and you get 665uF. Nearest higher standard value is 680uF.Of course none of this takes into account the inductance of the coil but that's not given. I assume 9mS is too long a time for it to be important.Whew! I never did that before - hope it's right!Thanks once again for a really useful instructable, I would never have found out the reason for discrepancy in relay coil voltage and operate voltage without you prompting me to do this!

• Useful and educational instructable. Now I know why a relay station is called a relay station!I don't think I will go so far as using the whole circuit with the magnet, but I will definitely use the trick with the capacitor in future!As an aside, you missed out an important pro of reed relays, which is they can be made to stand much higher voltages than normal types of relay. Also you can "roll your own" by getting a separate reed switch and adding a coil to it. You could probably also incorporate a holding magnet by doing it that way.Voted :)

Absolutely so. Like this: https://uk.rs-online.com/web/p/reed-relays/3491831/ can switch 10kV AC or DC.

• throbscottle commented on Nikus's instructable 5 Simple Ways to Determine LED Polarity6 months ago

Excellent tips - voted!But I have a few very old green LED's where #3 would have been wrong, actually the anode had the bigger plate in them. Definitely the exception though, I've never seen any others like it.

• Great idea with the PVC pipe. I never thought of re-forming it before. I've done the trick the the PP3 battery connector years ago, it's a really good idea. I'm also a big fan of re-using wires. Old CAT5 cable is also good for breadboards. You actually get a better connection if you use the stranded sort though. You can strip old multi-core cable for hook-up wire too.I don't like using non-insulated croc clips because they tend to short too easily. You can improve the connection on the bought leads though by soldering the connection or even just crimping it a bit tighter.Nice and useful information though - keep on experimenting!

• throbscottle commented on dankly1's instructable Cheap DIY Front Panels7 months ago

I was hoping you were going to show a way to etch the aluminium layer and expose the black underneath! Still a nice looknig panel though. Good work!

• It's the same wire as the leads going into a manufactured light bulb, so you could break open a blown bulb and re-use the wires.

Totally amazing! Are you going to try doing nitrogen fill like commercially made bulbs?

• throbscottle commented on lonesoulsurfer's instructable Fizzle Loop Synth II8 months ago

I love this. Way back when I was young in the 80's I tried combining oscillators to get interesting sounds (didn't really understand what I was doing, but hey), but the Fizzle Loop is better by a long, long way. I enjoyed finding out what a Vactrol is - I'd never heard of them before. It would be interesting to find out what changes if you used a bulb rather than an LED.I might actually build this.

• I love this idea. Definitely a keeper...

• throbscottle commented on themakermonster's instructable Glowing Bread Lamp8 months ago

• throbscottle commented on FrauMartina's instructable DIY Epoxy 'Enamel' Pins 9 months ago

These are great, and got me wondering about an alternative to 3D printing since I don't have one.Nice to see the £1 shop epoxy being put to good use! I must try it :)I'd never thought of using epoxy for decorative effects before, and have wished in the past I could colour it.Such great ideas, thank you!

• This is so clever, I'm very impressed!If you solder both ends of the LED to the middle of a piece of 0.1mm magnet wire and then cut away the bit in between, you will get super-fine leads and not hard to solder.You could analogue-multiplex a load of them and get some really nice effects! Maybe even wearable!I'm so impressed I can't tell you how impressed I am!

• throbscottle commented on PFO's instructable Fixing a Slipping F-clamp9 months ago

Wow, I have this exact clamp! Possibly the only decent tool ever made by Blackspur. Came fromt the £1 shop years ago, still going strong!

• 9 months ago

Is it your own design of SMPS?Can you supply a schematic please? It would be good see how it works and not just follow a construction guide.I have a box of old ferrite core transformers I wanted to open, thank you for showing the method!

• throbscottle commented on throbscottle's instructable Tiny Load - Constant Current Load9 months ago

You are most welcome. May I ask why you needed gerbers in preference to the PDF?

• throbscottle commented on throbscottle's instructable Tiny Load - Constant Current Load9 months ago

Hmmm, apparently I can't do that on Instructables. Guess it won't hurt to put them here anyhooo...

My PCB layout software will create them, yes. Do you mind if I send the file personally to you though, otherwise it's too easy for my (flawed) designs to find their way into mass production by someone unscrupulous!

• I'm sorry I don't understand what you mean by "wind coin"

• throbscottle commented on SimonRob's instructable Bi-color 5mm Led Ring (DIY)10 months ago

Well, you see light-clusters on cars being made with the same design now - looks nice, yes?

Very clever idea. I will try to use it for something. Voted!

• It's an interesting point, having read the conversation following your comment. If you look at mass-produced objects, the irregulatiies you get with articles which have been hand made (or at least, hand-finished), no matter how accurately done, always make it look far better than the precise lines you get with patterns cut out by a machine. Nothing can imitate the human touch. (well, not yet anyway!) even to the point where a hand drawn pattern has been machine cut (or painted), it still looks worse than if it's been hand cut/painted.

Voted!

• throbscottle commented on Nematic!'s instructable How to #2 - Use LTC3780 10 months ago

Nice useful instructable

• throbscottle commented on jazzzzzz's instructable Two Transistor Logic Probe11 months ago

I built one like this over 30 years ago. Very useful little tool! You have inspired me to make another...

Clever idea. I'm planning a general purpose "control panel" to go with a breadboard, this is an ideal way to include LED's. I'll definitely be using your schematic!

• throbscottle commented on BasinStreetDesign's instructable Tube Breadboard11 months ago

Hey I recognise those spring clips! Way back in the late 70's or early 80's I bought a bag of 10 or 20 from Tandy, when we had them in the UK. I think they were silver plated. Very similar construction. I could never find anything I wanted to use them for, though I thought they looked really useful when I got them. Sadly long gone along with everything else from time.

• throbscottle commented on Tuomas Soikkeli's instructable Wise Vise Bench1 year ago

That is so impressive! Well done :)

• Utterly impressed! Voted

• This is really interesting! I got interested in EPS a few years ago as I wanted to find a recycling facility for it for the company I worked for. At the time (2010) there didn't seem to be any commercial recycling of it, just a big machine you could buy to melt it down by the cubic meter (or more) into blocks for compact disposal.I was pleased to discover that apart from the space it takes up in landfill it is a "less bad" plastic because it isn't derived from oil as other plastics are.Could heat alone get the bubbles out?

• throbscottle commented on ThomasVDD's instructable Reflow Soldering Hotplate1 year ago

Really clever project. Those "live hinges" look really nice, though the laser cutting is way out of my budget. Reclaimed steel for me! Just need to find a hotplate...

• throbscottle commented on Bean_MD's instructable The Back Pocket Soldering Kit1 year ago

Brilliant - voted. Really clever how the coil draws the flame up so it heats the actual tip.I especially like the way you use the tin lid / magnet / alligator clip combination

• throbscottle followed JunieGenius1 year ago
• throbscottle commented on JunieGenius's instructable Robotic Cloaking Device1 year ago

OK you've got me stumped. How does the Arduino know when the line is at the end of its travel?Actually quite an educational instructable now I've looked properly!

You made me laugh! Thank you :)

• Puts me in mind of the Psion back in it's day - something I wanted but could never afford!Pi-son, perhaps?Brilliant little project. Voted :)

• throbscottle commented on Aleator777's instructable Apple II Watch1 year ago

Completely bonkers. Amazing, but bonkers. Love it :)

• throbscottle commented on Tye Rannosaurus's instructable Banana (slug) Cream Pie1 year ago

Completely amazing. I'd never heard of "banana slugs" before, maybe because we don't have them in my country. They look very realistic though! And the pie recipie looks delicious!

• 1 year ago

It's a really attractive PSU - and a bit of brute, too, in it's modest-yet-attractive casing!Personally I wouldn't use bare terminals like that at the front - though they are very pretty. I just have too many things on my bench that could accidentally short against one or both of them.I like your "floating" meters - though I'd have tried to make a panel for them the full size of the front of the unit so you wouldn't see any edges. But then I can see that could potentially look a bit naff in other ways.Why not make the fan speed be dependent on the temperature in the case? You can use a transistor to sense the temp in the case (or directly on the main heatsink you want to cool), use a 4 wire fan and connect a 556 dual timer as a voltage-controlled pwm fan speed controller.Anoth...

see more »

It's a really attractive PSU - and a bit of brute, too, in it's modest-yet-attractive casing!Personally I wouldn't use bare terminals like that at the front - though they are very pretty. I just have too many things on my bench that could accidentally short against one or both of them.I like your "floating" meters - though I'd have tried to make a panel for them the full size of the front of the unit so you wouldn't see any edges. But then I can see that could potentially look a bit naff in other ways.Why not make the fan speed be dependent on the temperature in the case? You can use a transistor to sense the temp in the case (or directly on the main heatsink you want to cool), use a 4 wire fan and connect a 556 dual timer as a voltage-controlled pwm fan speed controller.Another commentator raised concerns about EMI shielding. Simple solution to my mind is line the case with foil, then just the front is un-shielded. Also make is more fire-resistant...

I thought Lexan was the more expensive of the two?

• throbscottle commented on raul7321's instructable Key-Macro1 year ago

Nice project. It reminds me a bit of the "jog dial" that was on a Viao I once had. Handy little thing.Maybe you could consider doing a version that features a rotary encoder...

• I really like this project, thank you for taking the trouble to document your efforts.I've always liked VFDs and have just ordered one (well, 2 actually) 9 digit + dp + comma + arrow-below-digit to display the frequency of a signal generator (using AD9850 eBay module) I'm designing. I only have 6 pins available on my micro, so found the (serial input) PT6315 which will support 9 digits x 19 segments - might be suitable for one of those fancy VFD's you played with. It also can scan a keypad. They do bigger versions for more segments and more keys.Your instructable actually came up as the only search result when I was searching to find out about fake versions of this chip!

• throbscottle commented on deba168's instructable DIY Professional 18650 Battery Pack1 year ago

You can get 18650's with tabs pre-welded on, so you can just solder the tabs together. I've done this with NiMH cells and it worked really well.Also the type of welder for battery tabs is a capacitive discharge welder, I've not tried it but looks easy to build a simple version, much cheaper than buying one. Lots of CDW projects on the 'net!

• It looks like it's there to ensure C1 always gets discharged

You could but you will have to adjust R2 and R1 to get a fairly low gain. I don't know the power of headphones but I think it's in the order of a few hundred milliwatts, so I'd try a gain of 10 to start with and increase or decrease from there.

Thanks for the informative instructable - I knew nothing about these "chipamps" until today! Also thanks for the great link to the Analog .pdf on decoupling. Just what I needed!

• throbscottle commented on r570sv's instructable Rocket Ship Panel1 year ago

I was thinking "awesome" but now I'm thinking...Epic!Thank you for sharing :DIt might be worth looking at "front panel designer" as a layout program (free). The clue is in the name...

• throbscottle commented on UtkarshVerma's instructable 5V Mini Portable Power Supply1 year ago

What a great idea! I like that it is made on the battery clip so you don't have an extra "box" connected.Would be even better if you could make a version using a buck converter. MC34063 is easy to use, common, and cheap!

I also think it would be a good idea if you have a protection diode connected backwards across the battery, so if you accidentally try to put the clip on the wrong way it will short circuit the battery instead of destroying the regulator!

• I confess the pin guide is a really good idea - I may have to make one. Nine times out of ten I get the terminal in the right place though, by being very careful!

• Very informative piece, thank you.I bought a very cheap crimping tool which looks a lot like yours, and found it has a peculiar problem - instead of curling the "conductor crimp" around into two neat humps, it pushes them down so I get a partial crimp with a gap in the middle and two little flanges on the the back. I made a quite a few of these before I realised there was a problem. So I bought another very cheap crimping tool of different design, which also doesn't crimp properly but does form the "conductor crimp" into a better shape.So now I start the crimp off with the second tool I bought, and finish it with the first one, the result being quite good looking crimps. Still not as good as the commercial ones, but far better than either tool on it's own (and still ...

see more »

Very informative piece, thank you.I bought a very cheap crimping tool which looks a lot like yours, and found it has a peculiar problem - instead of curling the "conductor crimp" around into two neat humps, it pushes them down so I get a partial crimp with a gap in the middle and two little flanges on the the back. I made a quite a few of these before I realised there was a problem. So I bought another very cheap crimping tool of different design, which also doesn't crimp properly but does form the "conductor crimp" into a better shape.So now I start the crimp off with the second tool I bought, and finish it with the first one, the result being quite good looking crimps. Still not as good as the commercial ones, but far better than either tool on it's own (and still much cheaper than a decent tool which I simply can't afford)It's a good job I don't do many...

• Amazing. It looks like something on a Sci-Fi spaceship...