555 pcb - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: September 01, 2019, 04:45:26 am
content: hi all ive been working on a 555 timer project,got it working spot on,thats on a breadboard,i have to get something built for the 5th sept to demo,im having issues with my pcb design software,will attach the schematic,would anyone help by trying to knock up some pcb artwork for it for toner transfer,the resistors are going to be pots mounted off board and the caps are a standard disk ceramic and a small 10uf radial electrolytic,size isnt an issue,thanks in advance m3vuv.

author: m3vuv
author_rank: Super Contributor
timestamp: September 01, 2019, 04:46:54 am
content: the sounder isnt needed just a cpple of pads to connect a mosfet offboard so just 2 solder pads.

author: German_EE
author_rank: Super Contributor
timestamp: September 01, 2019, 08:19:11 am
content: Your home brew spirit is to be admired but in this case there is no need to reinvent the wheel:https://www.conrad.com/p/timer-assembly-kit-conrad-components-195901-12-vdc-05-150-s-195901For about 15 GBP (Conrad are in the UK) you get a PCB and all the components plus a decent assembly manual. I've been doing electronics for over fifty years yet I still buy these whenever I need a timer for something because they're so damn convenient.

author: m3vuv
author_rank: Super Contributor
timestamp: September 01, 2019, 11:20:34 am
content: thats not the point,my eagle cad wont run on this pc,thats why im asking,i need this asap plus i need to make a few,should only take a few mins with decent cad software,if it was a one off fair enough.

author: ledtester
author_rank: Super Contributor
timestamp: September 01, 2019, 11:58:37 am
content: This guy used EasyEDA to create a toner transfer pattern:

author: OM222O
author_rank: Frequent Contributor
timestamp: September 01, 2019, 02:15:33 pm
content: Quote from: m3vuv on September 01, 2019, 11:20:34 amthis is probably the 5th time you're requesting people to make a PCB for youthe main question would be, when will you be so kind as to "fix" your eagle cad OR learn something like easyEda that you can run literally on any computer (tested my 2005 laptop and it had no issues!) since it runs on your browser?anyhow, like the last 4 times: YOU HAVE NOT SPECIFIED ANY FOOTPRINTS OR ACTUAL PART NUMBERS.what is a "standard disk ceramic"? the "standard" has many sizes of footprints ..."size isnt an issue" how can that be? you're just going to bodge solder it? at that point why not use a veroboard instead of a PCB? a bodge is a bode regardless of how "nice" the board looks.your part count doesn't seem like it's a lot, honestly the veroboard method should work just fine

author: MarkF
author_rank: Super Contributor
timestamp: September 02, 2019, 03:38:59 am
content: No details. Need it yesterday.Making a point!

author: m3vuv
author_rank: Super Contributor
timestamp: September 02, 2019, 01:55:59 pm
content: ive got so called easy eda,seems a bastard to use the disc ceramic has about a 5mm footprint,size of the board isnt an issue,trust me if i could do it myself i would,i find veroboard messy and too time consuming,bear in mind i may have hundreds of these to make,didnt realise i was asking the earth,i would think a simple track layout foe someone who is good with pcb software would find it a 10n mins job,ive done a few freehand but the board marker dissolves in the etchant,didnt realise i was asking the earth!!.

author: m3vuv
author_rank: Super Contributor
timestamp: September 02, 2019, 01:58:25 pm
content: also im refering to o bog standard lm 555 timer ic thru hole.

author: themadhippy
author_rank: Super Contributor
timestamp: September 02, 2019, 02:17:44 pm
content: Quotei find it pretty easy,its got its quirks but for the price its great.Quoteif thats the case redraw your circuit in easy easyeda-press the covert to pcb button -layout the components-hit autoroute-hit order pcb. By the time youve bought the bare boards,transfer material,etch fluid etc youll have spent more than getting them made,and thats without factering in the time taken to etch 100 pcb's

author: MarkF
author_rank: Super Contributor
timestamp: September 02, 2019, 03:21:02 pm
content: Quote from: m3vuv on September 02, 2019, 01:55:59 pmNothing is simple when you don't have a complete specification!I takes so long because:No footprints or actual part numbers are specified.No off board connections specified (i.e. no component specified or no pad size specified or no wire gauge specified).Through-hole or SMD not specified.Desired board size and shape would be helpful as a target.A complete schematic with the parts to be included on the board is mandatory.No connector types specified.Time frame too short. Allow at least 4 to 6 weeks for layout and manufacture (Unless you want to pay massive shipping cost).For this small board, allow more than 4 weeks for standard delivery. Having this board manufactured for a Sept 5 demo is totally unrealistic.We can not read your mind.Work out your PCB design software computer issues.If you don't like EasyPCB, I useDipTrace. It was easy and quick to learn for a hobbyist. Two layer and 300 pins for the free version. You could have done this PCB yourself in an afternoon.There is also KiCAD. It is best to layout your own boards.Quote from: m3vuv on September 01, 2019, 11:20:34 amSince you are familiar with the Eagle software and how to layout a board, you KNOW you are NOT providing enough information for people to help you. The last PCB I tried to help you with, you would NOT even provide sufficient answers to direct questions. The component sizes/footprints you did finally provide where NOT valid parts. I am willing to help people but I have LITTLE tolerance for flippant answers and the "run-around".

author: OM222O
author_rank: Frequent Contributor
timestamp: September 02, 2019, 04:58:09 pm
content: I'm assuming your "about 5mm" means 0.2" capacitors?Honestly just have a look:the first 3 are radial capacitors (i.e: "standard disk ceramic") with 3 different pin pitches!the next few are SMT caps, again, all with "standard" footrpints. obviously you can't shove a 0201 cap on a 1206 pad or vice versa ...Also like others mentioned, if you needed a demo, maybe you should have acted faster? giving 3 / 4 days isn't enough for making 100 PCBs ... unless you pay insane costs like others mentioned for DHL express which still takes 2 days!

author: Renate
author_rank: Super Contributor
timestamp: September 02, 2019, 06:44:35 pm
content: I'm sorry, m3vuv, that this is all a bit frustrating, but some parts of this aren't well thought up.You're talking about a project where (apparently) most of the parts are off board.What is this MOSFET that you're feeding? Where is it getting power? Why isn't it on the schematic? Why isn't it on the board too?Why isn't the pot on the board? What are the physical requirements?You've got the pot going between VCC and pin 7. When it's turned up all the way, it's a dead short.The discharge transistor on pin 7 will not like that at all (but might not actually blow up).You need another resistor in series with the pot to increase minimum resistance.Not only that, it will keep the maximum tick rate from going through the roof.You're using an electrolytic capacitor for the timing element?A garden variety electrolytic cap might be +80/-20% tolerance.You don't have a lot of range on your pot to adjust for such a variance and still cover your 60-180 BPM.Also, that capacitor is going to age too.Especially if you are going to build 100 of these, you really have to consider minimizing off-board connections, hand wiring and getting uniform results out of them all.It's probably not what you want to hear, but maybe a little microprocessor would be easier to do such that 100 of them all work at the same rate without any calibration.Another trick that was done in the old days was to run the oscillator at a higher frequency, then use a divider.This allows you to use smaller, precision capacitors.

author: Renate
author_rank: Super Contributor
timestamp: September 02, 2019, 11:35:12 pm
content: See my video:https://imgur.com/a/RYHdFR7

author: m3vuv
author_rank: Super Contributor
timestamp: September 02, 2019, 11:44:14 pm
content: my throne together setup works well adjusts from a pulse every 8 seconds to 14 seconds and the duration from .5 seconds to 6 seconds,the pots are to fine tune the chemical dose rate,the calcs come at the valve beeing open for one second in every 10.,its for a chemical to break down fat in sewer systems,currently beeing trialed by thames water and mc donnalds,has a huge market potential.

author: Renate
author_rank: Super Contributor
timestamp: September 03, 2019, 01:19:08 am
content: Well, the things that you said in your last postare the things you should have said in your first post.

author: m3vuv
author_rank: Super Contributor
timestamp: September 03, 2019, 02:00:39 am
content: in the end i drew it by hand ,mirrored it resized it and laser printed it then toner transfered it,worked out faster for me that way.