circuit writer pen

Thread Starter

brozizds

Joined Aug 15, 2010
135
I have been working of this project for quite some time with the guidance of Bill Marsden's great circuit designs all of which I got to work on my protoboards. Now that I am trying (remember newbie) to apply to my circuit board I'm having problems. I tried using a circuit writer pen but found out that I was losing voltage the further I got away from my 9V power supply. Has anyone had this problem or am I doing something wrong? Would I be better off just running bare copper wire on my Positive and Negitive sides of my board jumping from one component to another? I need some help here and suggestions. Thanks :) jim
 
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Wendy

Joined Mar 24, 2008
23,429
Are you trying to draw a circuit with conductive ink? This is not a good way to go, as you have found out.

You can either use a perfboard (which is what I do). I prefer the ones with copper pads.

Or you can make a PCB (printed circuit board). This process is a bit messy, but reasonably easy to do. One of my favorite web sites was written by a gentleman who also visits here, I "met" him years after I bookmarked his site.

http://www.fullnet.com/~tomg/gooteepc.htm

Long before I read this article I was making PCBs with a sharpie (a magic marker) and Ferric Chloride (available from some Radio Shacks, but getting harder to find). You can also use other chemicals such ammonium perchlorate (available from Fry's), or a mixture of Muriatic Acid and Hydrogen Peroxide, which Tom describes in his article.

Muriatic Acid is a swimming pool chemical (and is another name for Hydrochloric Acid), and is available from most hardware stores. With all these chemicals gloves should be worn.

He describes how to use a laser printer to make extremely professional looking PCBs, I've done this. The sharpie method is great too, and easy to use.

Ferric Chloride stains everything it touches (including people), and the fume tend to damage tools. When I store it I wrap a rolled up paper towel tightly around the lid and tape it in place. The fumes will eat the towels paper, and your tools are saved. This is the voice of experience. :rolleyes:

If you want to see an example of using a perf board (also available from Radio Shack) look here.

Project: High Power LED Flasher

Quick side note: Radio Shack marks up everything. I don't begrudge them a profit, but I do using my money. :D My personal cost for a small PCB perfboard is 69¢ from several Mom and Pop operations in Dallas.
 

marshallf3

Joined Jul 26, 2010
2,358
The problem with that article is that while the theory is correct, Staples has once again changed their paper. I bought some of their basic glossy and it now has a plastic film on both the front and the back. The film on the back meses up your iron, the film on the front is now very toner-attractive so it doesn't release anywhere near as well as it's supposed to.

People keep suggesting the slick paper that newspaper ads are printed on, tried some of that but it was too thin for the printer I was using so it kept eating it. I think I'm going to try doubling the paper up, or ironing some of it onto the now sticky Staples paper.
 

Wendy

Joined Mar 24, 2008
23,429
A lot of people suggest using glossy paper used in magazines. I'll eventually try it myself.

Several years ago I stocked up on Staples paper, I'm set for a lifetime.
 

Thread Starter

brozizds

Joined Aug 15, 2010
135
First thanks for the info. on conductive ink. now I am building my boards and testing them I have eight to do and when I pluged in the 555 's in I purchased from BG the the both LEDs and the piezo go off but when I use the ones I got from RS the timer works fine ? whats up? the nos. on RS mod. are NE555P the nos. on the BG mod. are ICM7555 is the BG low volt mod. Help:confused:
 

Wendy

Joined Mar 24, 2008
23,429
Different 555s made by different manufacturers might have slightly different specs, but it really shouldn't matter. A CMOS 555 (such as the 7555) is a different animal. There is quite a bit of difference between conventional and CMOS types.

OK, you are using a variation of this schematic?



If not then what?

Second question, are you trying to make a PCB, or are you trying to breadboard it on a perfboard?
 

Thread Starter

brozizds

Joined Aug 15, 2010
135
Bill,
I found my sales slip from BG and it says I ordered TLC555 part # ICSTLC555 . Is this the correct number or did I order the wrong parts? thanks Jim
 

Wendy

Joined Mar 24, 2008
23,429
If you do any projects you will find uses for the TLC parts, they are CMOS 555 chips.

For your immediate application you have the wrong chips. How many 555's do you need?
 

punisher454

Joined Jun 29, 2009
16
Last summer I built a circuit board printer from a modified Epson WF30 inkjet printer.
Easiest rapid home PCB method yet.
steps;
1. layout circuit in prefered software.
2. print to pre-cut thin cardboard feed stock
3. prep PCB, then pre-heat in toaster oven (to around 180f)
4. place hot pcb on cardboard carrier exactly over test print and tape corners.
5. print
6. remove from carrier and bake in a toaster oven.
7. etch
8. remove baked on durabrite ink with isopropyl (or whatever you like)

I have successfully printed several boards with TQFP100 pads (.5mm pitch) with great results.
Epson durabrite ink is pigment based (like a sharpie). The magenta and yellow seem to resist etching better than the black and Cyan. I print all RED for best results. Pre-heating the board helps the ink stick and start drying immediately which helps prevent "fish-eye" pin holes.

A few pieces of plexiglass and a fishtank airpump made for a nice and inexpensive vertical etching bubbler too.
 

marshallf3

Joined Jul 26, 2010
2,358
I still want one of my old HP "grab a pen" plotters back. One worked, one was for parts. I had pretty well come to a time in my life where experimenting with small circuits no longer interested me and with space at a premium I ended up selling them on eBay.
 

thatoneguy

Joined Feb 19, 2009
6,359
I threw away my "Circuit Writer" for circuit board repair or post-etching changes. In exchange 3M makes a pretty awesome Copper Tape. It is copper sheet (~2 oz PCB thickness) with a conductive adhesive backing, and is fully solderable. I keep rolls of 1" and 1/2" handy, and can X-Acto knife cut some fine curves to replace a blown trace or re-route a mis-design and end up with awesome looking results over the issues of using a chunk of wire to jump gaps (RF interference, etc).

It can also be used as shielding, though it is a bit on the expensive side for such uses, it is marketed as 3M 1181 Foil Shileding Tape

Cost is between $12 and $100/roll depending on width and length of roll.
 

thatoneguy

Joined Feb 19, 2009
6,359
can anyone direct me to a pretty descent circuit writer pen tht does conduct current
Other than the copper tape I mentioned above, there really isn't one that works reliably.

Since keeping the tape around, I've not once thought "I wish I had a Circuit Writer Pen". It's just too easy to cut the tape to what you need and stick it on. For about the same cost as a Circuit Writer pen, you get a lot more conductive stick out of the tape as well, linear inch speaking.
 
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