Tell us about yourself!
Complete Your Profile- JohnathanW15 commented on nrepak's instructable LED Water Purifier4 months ago
- JohnathanW15 commented on nrepak's instructable LED Water Purifier4 months ago
meant to add This info comes from my research before designing a vacuum press uv exposure box for uv lithography/etching circuit boards. I havent looked into uv-c transparancy in low iron glass but im guessing its beter than many/most plastics
View Instructable »low iron glass or quarts (as mentioned ) is better for more than one reason. Many plastics block uv... worse yet, many plastics break down when exposed to it. Plastic + UV + water...might = drinking plastic. Normal glass has a slight green tint to it. its best seen looking at an edge. That green comes from iron mixed in with the sand its made from. It used to be an impurity but now its added in a controled percent to increase flexability (if memory serves)... it has the unfortunate effect of blocking/reflecting a lot of light below about 400nm. UVC is < about 300nm... again from memory but should be close.
- JohnathanW15 commented on camscam's instructable Light Therapy for Less Than $60.008 months agoView Instructable »
I would avoid any expert making such a general claim. Light itself is Electromagnetic pollution or a tool depending on if you are reading or trying to sleep. ever notice how bright a flash light has to be to shine through your hand? it can be done but its a very high output light held right to the flesh. and you might see a dim glow. your cheek is a better place to try it. This demos the concept of Electromagnetic radiation at high frequency not passing very deep into the body. To begin with every time you double the distance from the emiter the power level drops to 1/4th its intensity. combind with the fact that even strong high frequency EM held up to the skin (the flash light) struggles to shine through thin parts... I wouldnt worry much about the 2watts of EM radiation 10 feet from ...
see more » - JohnathanW15 commented on cpeniche's instructable Dry Film Photopolymer for Making Circuit Boards8 months agoView Instructable »
it depends on the data sheet for the film u buy and sometimes varies with what resolution you aim for. The blue to purple stuff that is easy to get on Amazon and ebay at the moment is what he appears to have used. I'm using it Untill the harder to source replacement arrives and if that doesn't go well I'll bite the bullet and get real riston. Anyway. 0.85 to 1 percent at about 100f for no more than 60 seconds before rinse is how u want to do the blue stuff. Google solid dilution in water formula to figure out the math. You need to clean your board b4 applying. I use 3 baths and green scrubbers for dishes(but not already used on dishes). 1) 5 percent hcl bath to scrub off oxides and make it all shiny. 2 acetone 3iso pro. With rinse between. Use distilled water for rinsing and b...
see more » - JohnathanW15 commented on cunning_fellow's instructable The Etchinator - Low Cost PCB Spray Etcher (under $100)9 months agoView Instructable »
what if you used really slow pulsed a brushless with axial fan?
- JohnathanW15 commented on Railes's instructable Gold Recovery Correctly9 months agoView Instructable »
what do you have against nitrile gloves? can you provide evidence to support your opinion? most gov, industry and edu produced charts ive read rate them as ok for at least "incident contact" with everything involved here.
- JohnathanW15 commented on ProjectPlace's instructable How to Extract Gold From Electronics9 months agoView Instructable »
how about pool acid? aka 30% hcl for adjusting the ph in pools... aka (idioticly and archaicly) muriatic acid
- JohnathanW15 commented on hobby16's instructable Modified Laminator for PCB Toner Transfer9 months agoView Instructable »
mort chien imaginarie! /s thanks for the great tutorial!
- JohnathanW15 commented on justwags's instructable DIY Arduino Dual Pulse Capacitive Discharge Spot Welder10 months agoView Instructable »
guy on ebay selling them. i looked a few weeks ago and he still was.. shipping added like 30 if i recall
- JohnathanW15 commented on The Real Elliot's instructable Stop Using Ferric Chloride Etchant! (A Better Etching Solution.)10 months agoView Instructable »
what if i happen to have a spare medical oxygen tank? asking cause i know little about chemistry but want to avoid things that go boom and etch with out the help of fire department.
- JohnathanW15 commented on Nematic!'s instructable How to #2 - Use LTC3780 10 months agoView Instructable »
what resistor value on the CC terminals would set it wide open (no current limit) Im trying to save space and the pots are slightly higher than the caps so Im taking them off for a thinner case. I need 24-26v (currently resistors replacing CV are giving 26) and no limit on amperage. The device attached draws 2amps max but im not quite sure how to tell if its limited by the 3780/psu or not as i cant force device to max power and dont have power resistors I wouldnt turn red hot
- JohnathanW15 commented on lancandy's instructable $30 High-Speed PCB Drill Press10 months agoView Instructable »
ever heard of rental? I can get an air compressor for 4 hrs for 15 bucks at mennards. if you are doing so many you need it for more than 4hrs, you should probably be sending out to have your boards made. also, If you dropped the attitude you have you might manage to make friends with someone who owns a welder. in my experience most people that own them are happy to do a project as small as that for you/with you for a 6er of beer you will probably consume with them...or just conversation
- JohnathanW15 commented on SolarFlower_org's forum topic I accidentally invented a device to collimate any light source into a concentrated beam... what should I do with it?10 months ago
not an expert but I seem to remember from college astronomy lab and diy flash light builders forms that the moment you add mirror or lens you have losses. so claiming a 100watt light will be a 100watt laser makes you sound like a bit of a nut. also, i hope 8 years after you are posting this all lights you have are consuming something more like 5-20 watts if no get some LEDS bro
View Topic »I hear dissimilar ages are more accepted in germany
- JohnathanW15 commented on synthdood's instructable DIY PCB Using Liquid Photoresist 10 months ago
er...any kind of etch resistive ink, wouldnt need to be photo
View Instructable »question that strikes my mind is, can you fill an inkjet carriage with the PR ink and then modify the rollers to pull a pcb (in a 8x11 sled w/cut out) through
- JohnathanW15 commented on JoeyJunior's instructable How to Make a Printed Circuit Board (PCB) Using the UV Light LED Method.10 months ago
pst...miter or tabel saw with 10inch 80 tooth $25 buck blade from harbor freight. my 5400rpm compound miter blasts through 1/4 in plexi w/o a chip... only issue i have is ryobi cm saw doesnt get or stay square very well so for my current project i took the blae to a friends house cause he had a compadible dewalt table saw. saw was like 3xxx rpms and still very little a few chips to none at all
View Instructable »uh in practice it would seem connecting a bunch in series and multiplying nominal FV is done all the time. esp if hooked to a cc/cv dc-dc converter. Pull the light strip off a dead lcd once (make sure its not old ccfl style )
- JohnathanW15 commented on Well Done Tips's instructable DIY: Increase Battery Capacity by Changing 18650 Cells10 months agoView Instructable »
gonna recondition lipos?
- JohnathanW15 commented on fozzy13's instructable NiChrome Hot Wire Cutter for Acrylic11 months ago
do you find this accurate enough to knotch a usb sized hole at an arbitrary place and have a nice square ish cut?
I doubt you could at 2am on a work night in a large apartment complex... at least from the comfort of your desk/work bench in the unit. ie the hot knife wont disturb the neighbors like a rickety desk transfering the momentum of your saw into the floor. It also doesnt require clamping each piece
View Instructable »google "how to use a search engine" , then go from there.
- JohnathanW15 commented on nmarquardt's instructable RFID Reader Detector and Tilt-Sensitive RFID Tag1 year agoView Instructable »
if you still have this/ever try it again.... I think non conducting tape over the first layer except for one little edge then another layer of coper joined to that exposed tap and laid over the insulator layer (connected spiral of copper tape > insulator tape) vertically would work a bit better. dont bother with inward spiral as author of tutorial showed. The coils in the devices are usually vertical stacks. If you do EE stuff semi regularly you should pick up a roll of whats called "kapton tape" insulates and can with stand the heat of a soldering iron(like under the copper tape...solder doesnt actually stick to it.) If you have ever seen the transparent yellow orange tape on a lipo pack or inside electronics you probably respect this adhesive already, every time i see it ...
see more » - JohnathanW15 commented on jts3k's instructable Controlling solenoids with arduino1 year ago
use a "logic level mosfet" they come in N and P variety. N turns on when the gate pin is driven high, p turns on when get is grounded. you can also use p channels as reverse polarity safety devices on stuff you build and frequently connect/disconect power wire... if you tie the gate pin to ground then connect positive through the remaining terminals... the switch will be off if positive gets connected where ground is supposed to be on your power in. ;)
View Instructable »i forgot to mention, after checking a mosfet can handle the volts and amps you need, look for RDS on value... that is the resistance through the part when the "switch" is on. n channel is lower but p channel is easier to use and still very reasonably low.
- JohnathanW15 commented on jts3k's instructable Controlling solenoids with arduino1 year agoView Instructable »
its 2017, use a n or p channel mosfet
- JohnathanW15 commented on The Real Elliot's instructable Stop using Ferric Chloride etchant! (A better etching solution.)1 year agoView Instructable »
that dude is one hell of a buzz kill. thanks for the great tutorial
- JohnathanW15 commented on matthewbeckler's instructable ATX to Lab Bench Power Supply Conversion1 year agoView Instructable »
Matthew, have you been on ebay recently? CC/CV boards cost 5 bucks for a stated 5 amp boost or buck...reality is 2-2.5amps unless you put some metal fins or odd chunk laying around on them. .One can get a Poly fuse multi value kit for dirt cheap as well. need more amps? If they have roughly double the budget have them search ebay for ltc3780. 10-12 bucks and a month wait to get one from china using an IC from Linear Tech in Cali. or you can get a board from an american based ebay shop in a week for about 23 bucks.worth noting:its auto regulating boost buck...the chip itself can do just about any form of power converter by re configuring (sepic, cuk etc ) I know all this because im prototyping a product and also keep a bunch of those cheap no name Dc-DC converters on hand for what ever ...
see more » - JohnathanW15 commented on vicvelcro's instructable Uninterruptible Power Supply - Extending the Run Time1 year ago
i think you are better off having an electrician install romex(house mains wire) and extending the AC output than separating the bat from the invert er by a great distance. your resistance losses will succccck the battery dry and wire will get hot. wouldnt you rather that power went to your devices than heat?
View Instructable »get yourself 3 solid state (normal will work but these SS is faster). Two should trigger with 120ac, the other ideally triggers at your MCUs 3.3 or 5v. on the other side of the mains triggered device, go from Vcc on your micro through a current limiting resister, to the other side of the relay back to a GPIO configured for input. Now you can loop and watch for it to go low. When it does go low raise another pin high, this will trigger the series configuration of the batteries to connect. With solid state relays it should happen faster than your gear turns off. for the P charging config use 2 standard coil based relays on one bat and join the charging sets (+ and - from both)after installing the relays mid line/before they join on one set of leads.... you only need to disconnect one batt...
see more » - JohnathanW15 commented on matthewbeckler's instructable ATX to Lab Bench Power Supply Conversion1 year ago
have you ever attempted to count the little lines that make up the digits in your "cheap 3 digit voltage meter"... u might find that there are 7, matt wasnt wrong calling it a segment display. Next time try to understand some people know more than you...trust me when I say it takes a lot of effort to find something to like about your build but he did and yet, you give additude in return
I would bet one could take the "black magic" out of it if they read the markings on the DC-DC converters and used google to find the data sheets.
View Instructable »nice dmm, u an eev blog fan? if you havent heard of it check it out. I ask because your choice in meter is one of his recomended ones
granted uvc is even worse... i use a 365nm uv led thermal pasted to a pentium 4 heat sink to do uv lithography at home. its not that much work to use uv-leds
they only recently came down to that price as well...a year ago they were like 300 an led
you were right...fyi they just dropped in price maybe half a year ago though. i give r&d a lot of props considering uvc destroys most plastics and damages many electronic components... not easy to make a semi conductor whos output is detremental to itself
yeah, i looked into it a bit more and intel has had a hell of a time with extreme uv lithography