I havent been at this long and i'm constantly learning from my mistakes.
So i thought i'd share a few things i've learned.
No1 Pots have little locating lugs on the top side that need removing before installation.
When i saw someone said cut it off with a pair of side snips thats what i did.
Heres my tip and i found that if you use a pair of long nose pliers and grab the lug and bend it towards the side it will snap it clean of and not leave an annoying ridge like it does if its cut off with side snips. So it will sit flat without the need to file off the remains.
I wish someone had told me this ages ago.
No2 Get yourself a wire colouring Scheme.
I spent most of the day wondering why my new ABY box wouldnt funtion. Especially since it did last night.
It turns out i confused the Input wire with the ground. The reason being they were the same colours on the output but the otherway round and i didnt bother to check because since the boost i used was one of the first projects i built, it didnt have a colour coding system like my latest projects.
Organisation is key and testing too.
If only the meat inspectors here had tested our meat we'd be eating real beef instead of Horse/Beef mix.
I like Horse meat. It's qaulity. I have eaten it many times when i lived in France. No Problem.
I do however object to being sold meat called Beef when i contains Horse.
I dont believe i have eaten any of the foods beleived to contain it and to be honest i think i'd spot it a mile off. The colour and texture and give it away.
Rant over.
Moral
Check your circuit is genuine real beef.
> Pots have little locating lugs on the top side that need removing
OR use them properly. I stick the pot in, rotate so the lug scratches an arc in the panel. Remove pot, run a line through the center. Bang a dent and drill, about 1/8". Now when you put the pot in, it will NOT rotate even when the nut gets a little loose.
> Get yourself a wire colouring Scheme.
Yes. House-wiring is color-coded for a reason. You shorted-out your guitar. Makes a few nano-Watts of heat when you strum hard. If you short house wiring you can have 100,000 Watts for an instant, enough to melt wires and spray molten copper in your face. While pedals are much less dangerous, your debugger's sanity requires as much self-evidence as you can manage. A 10-pack of assorted color hook-up wire is good to have. If you abandon a desktop PC, scavenge all the wires (at least the thinner ones). (Let the PC sit for a day UN-plugged-in so the caps discharge before you poke cutters in the wiring.)
Quote from: PRR on February 23, 2013, 12:15:31 AM
> Pots have little locating lugs on the top side that need removing
OR use them properly. I stick the pot in, rotate so the lug scratches an arc in the panel. Remove pot, run a line through the center. Bang a dent and drill, about 1/8". Now when you put the pot in, it will NOT rotate even when the nut gets a little loose.
> Get yourself a wire colouring Scheme.
Yes. House-wiring is color-coded for a reason. You shorted-out your guitar. Makes a few nano-Watts of heat when you strum hard. If you short house wiring you can have 100,000 Watts for an instant, enough to melt wires and spray molten copper in your face. While pedals are much less dangerous, your debugger's sanity requires as much self-evidence as you can manage. A 10-pack of assorted color hook-up wire is good to have. If you abandon a desktop PC, scavenge all the wires (at least the thinner ones). (Let the PC sit for a day UN-plugged-in so the caps discharge before you poke cutters in the wiring.)
something that always bugged me. Those tabs have a good use, it's self defeating to remove them all the time.
On my first pedal I used the tabs as Paul described. Works great, but the shafts were sticking a little too far out of the enclosure for my liking so that the knob didn't sit down close enough to the face of the pedal. I didn't like the way this looked and you could see the holes with the tabs sitting in the middle at the side of the knob. So on my next pedal I cut them off and used lock washers to bring the pot inside a bit. Just right! I could have looked for knobs that worked better, but lock washers and no tabs is a far easier fix - and when you have five knobs makes the measuring and drilling a lot easier too.
+1 on using the tab properly. and on prr's method.
another tip (for all comers) is to put an extra nut or extra washer on every pot you buy when self-serve shopping. as an ex-counterhand, I can say they are either too dumb to look/care, or only know about mobile phones.
I cut up old printer cables for hook-up wire. it's usually thinner insulation than store bought stuff. which is nice.
(I was wiring my percolator the other, had 2 wires left to pick/cut from a 25 colour/stripe cable, and I thought "no, I'm just not seeing the colour I need here .....")
If you use sockets for ICs, power the circuit up first time without the ICs installed and check you're getting the right voltages on at least the power pins. Also worth while making sure any reference voltages or the output any regulators are correct. This reduces the chances of frying your IC's and can make other debugging easier.
Worth while to a lesser extent with transistor builds as well, although you can often only check power as other voltages rely in the transistors being present.
-1 for pot tabs (is that a thing?) Too much faff, just snap em off.
Yeah, parallel printer cables are a great source for wire, I found a 5 metre one whilst chucking some stuff out a while ago, don't even remember where it came from. Probably got enough wire from that to last me a lifetime.
Safety tip for pot tab snapping. Aim the tab at the bench or trash can before you cut it. Mine usually fly off fast enough to damage an eye.
John you should switch to the method Kipper4 describes, that is, don't cut it off, just grab it, bend it over and it falls away, no burst of energy to dissipate, no stray projectiles to worry about, kind of disappointing that...
dave
Yep, I'll give it a try next time I have to neuter one... ;)
Quote from: Jdansti on February 23, 2013, 02:51:51 PM
Safety tip for pot tab snapping. Aim the tab at the bench or trash can before you cut it. Mine usually fly off fast enough to damage an eye.
pretty easy just to use a pair of pliers and hold onto it until it snaps off.
Needlenose for sure - Grips the tab perfectly. I have a small garbage container to my right when I'm standing at my bench. Stripping wire or popping these tabs, its always the same: Right over the garbage can. This leaves the workspace clean.
little tip for those 'snap off' lugs..
snap it off, and place in the gap of split shaft pots... voila' ..faux solid shafts...no squeeze at all. ;)
Always struggled with breadboarding, last night for the first time used a highlighter to mark off each component/connection on a printout of the schematic as they were added to the breadboard and things sailed along like never before.. Seemed to make the process much easier, instead of seeing a jumble of components and connections allowed me to focus on one part at a time and keep track of where i'd been and where i was going next.
All seems so obvious this morning, fun instead of frustrating... that said i haven't tried the circuit out yet but i'm confident.
dave
Quote from: deadastronaut on February 24, 2013, 11:13:43 AM
little tip for those 'snap off' lugs..
snap it off, and place in the gap of split shaft pots... voila' ..faux solid shafts...no squeeze at all. ;)
So that's the
real purpose of the tab!!! ;D
Quote from: timd on February 24, 2013, 02:50:26 AM
Needlenose for sure - Grips the tab perfectly. I have a small garbage container to my right when I'm standing at my bench. Stripping wire or popping these tabs, its always the same: Right over the garbage can. This leaves the workspace clean.
Until your big clumbsy fingers drop that last 100nF cap in the bin too... good idea though really ;)
Quote from: Jdansti on February 24, 2013, 01:53:58 PM
Quote from: deadastronaut on February 24, 2013, 11:13:43 AM
little tip for those 'snap off' lugs..
snap it off, and place in the gap of split shaft pots... voila' ..faux solid shafts...no squeeze at all. ;)
So that's the real purpose of the tab!!! ;D
These spacemen are bl00dy clever! :D
beep...............beep.....................just logical captain..... ;D
http://www.youtube.com/watch?v=6U45DS8LVrA
My best tip for anybody is NEVER work over a shaggy carpet!
And NEVER let your wife or mom vacume in a 100 feet radius of your work erea. (Learned that one in my model building years.)
use the least amount of flux that you possibly can when flux is needed ( when solder doesnt want to stick ) , when finished you must remove it . if you used flux clean the whole board with alcohol and a toothbrush , preferably your mother in laws , before the first test , you really must let it dry or use a hair dryer on low a bit .
if vero , first thing, scrub the copper side of vero with green scrubbie pad . mark all the cuts and double check before using drill bit to make trace cuts .
if perf , get vero , i kid .
i always file the connectors on the stomp switches a bit , just enough to scuff them , pretty sure this is wrong and ruins the pedal .
do not use ultra bright leds , if you do test them with a resistor and a wall wart first to see if they are retina melters . blinding pedals are frustrating . keep goin up to 15 k with the resistor to reduce burning holes in the ceiling .
build an audio test probe and Q n D osc .
start finishing or painting asap . triple the cure time . also 90 degrees means 90 degrees . better yet dont even paint the darn things :)
a piece of double sided tape used as an insulater on the bottom of the vero can work well in a pinch .
if you plan to use rubber feet , the adhesive that they have may not be the best , a smidgen of epoxy may work better .
number the vero , use a strip of masking tape and a fine point shrappie .
double check parts before cutting em in , use the meter on omega for resitors .
get a chart for capacitors and resistors and transistor pin outs but the last one may be tricky .
socket the transitors .
a bic lighter makes for a great wire stripper , in a pinch .
only use verified layouts
keep a fan runnin for fumes
dont eat drink or smoke while you build , wash up frequently , and when finished .
s m t w t f s - pill containers - if you can find larger ones , like the timothy leary style , those can work well to store the components as you actually collect everything off the BOM , or bill of materials . typically i use one for resistors , another for caps .
a set of test leads , multi colored wires with crock clips on the ends is always nice to have , but i can never seem to have enough .
multiple smaller breadboards may be a wiser investment than the circuilizer 3000 .
take breaks every half hour , take a quick stroll
before you fire it up for the first test , re-examine everything three times , slowly ... i almost always fudge something here , that sinking feeling , it can be avoided most times .
if you are planning to design your own unique circuits , modular units , say a tillman buffer , booster stage , diode switch box , decade resitance box ( see chromospheres channel ) are great ways to get your feet wet and really come in handy down the road .
start small . save the tough builds for later whn you are more confident and experienced . a lot does go into this process , it would be a shame , not enjoying the whole experience .
have fun
i wll take that nimmoy and run with it :
http://www.youtube.com/watch?v=AGF5ROpjRAU
Looks like Leonard has been testing Timothys drug stash again.
I have started a computer based pinout file and when i get the one I want on google (Right click save picture as)
A bic lighter also comes in handy for Heatshrink.
http://www.beavisaudio.com/techpages/Transistor-Pinouts/index.htm
http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/The-Mod-Zone-_/TRANSISTOR_SUBSTITUTION_CHART.gif.html
Quote from: Ronan on February 26, 2013, 06:19:18 AM
There is a quick check for breadboards drawing too much current - before applying power, measure the resistance between power (+9V) and ground. If you have say 100 ohms resistance, then the current will be at least V=IR, 9=I x 100, I= 90mA. Most chips draw a few mA each, bias resistors much less, its a good guess that most analogue circuits will draw less than say 30mA. So if you measure less than 300 ohms, then double check your circuit. Most circuits I have built measure well over 1K from power to ground. After I cooked a battery, I always do this check.
Stolen straight from Ronan but quoted appropriately. Seems like a sensible thing to do with any build before you attach your power.
how do i measure what amperage a circuit is drawing?
Its time i learnt this. I'm sure my DMM is capable of it, I've just never done it or been aware of the need.
Thanks for any help and advice you can give
I put together a small box that puts a 1Ω resistor in seies with the battery +ve. Battery/power supply plugs in one side the pedal plugs in the other side. Set the DMM to read mV and measure the voltage drop across the 1Ω resistor and that converts directly to a mA reading (ohms law).
(http://i216.photobucket.com/albums/cc305/davent/IMG_3276.jpg)
(http://i216.photobucket.com/albums/cc305/davent/IMG_3277.jpg)
As a matter of course i put a 100Ω resistor between the battery and the circuit with a 100µF cap to ground so if the pedal is only battery powered i can always measure the voltage drop across that resistor and calculate the current draw from that into.
dave
That just went right over my head i'm affraid.
Sorry for the dumb question but what does the Mv setting look like on the DMM
Is it the 200m/2000m setting in the DC voltage range?
DMM Pdf below if this helps.
http://www.drapertools.com/products/manuals/60792ins.pdf
thanks
i wish this was a video on you tube with explanations.
Thanks for all the help.
It wil be the lowest DC volt setting on your meter, measures milliVolts. Still waiting for the pdf to open but on all mine the lowest setting is 200mV.
dave
Can't do a video but this shows the setup.
(http://i216.photobucket.com/albums/cc305/davent/IMG_5184_zps310a0998.jpg)
Meter is set to read up to 200milliVolts (mV) so by ohms law, Current(mA)= Volt(mV)/Resistance(ohms) and since the resistance is 1Ω the meter can be read as mA even though the meter is set to the volt scale.
dave
thats making more sense now i can see how the meter is hooked up thanks.
I'll give this a go soon and start learning ohms law and its applications soon
thanks Dave
or you could use the dc mA range. stick the meter in series with the power supply and the circuit.