some breadboards
in [Design]
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From: Dave Platt on 10 Apr 2010 21:24 In article <6472s5907cqj42koi10i4q6vcsp9me4l6j(a)4ax.com>, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >Some sort of dremel circle cutter, like a tiny hole saw thing, would >be cute, to cut isolated circles. You can buy small hole saws intended for cutting stone and tile. They're metal tubes with industrial diamonds on the cutting edge. I got a set, quite expensively, from an eBay seller (a Chinese manufacturer of them, I believe). They make decent pad cutters for simple PCB circuits. -- Dave Platt <dplatt(a)radagast.org> AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads!
From: brent on 10 Apr 2010 22:43 On Apr 9, 6:22 pm, John Larkin <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > On Fri, 9 Apr 2010 14:00:58 -0700 (PDT), whit3rd <whit...(a)gmail.com> > wrote: > > >On Apr 8, 5:10 pm, John Larkin > ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > > >>ftp://jjlarkin.lmi.net/BreadBoards2.JPG > > >[shows a 74ACT04 with connection points] > > >But, what's the point of breadboarding a fast gate without the > >required bypass capacitors on the power pins? It's not gonna > >behave like the final application does. > > There was a surface-mount cap between pin 14 and the solder blob on > the copperclad. Looks like it broke, being tossed around in the > breadboard bin for some number of years. Note that this is an RCA > 74ACT04. I was astounded to see sub-ns rise and fall times, back when > everybody thought that CMOS was slow. > > John Have you thought about getting one of these ? I would love one http://www.lpkfusa.com/
From: John Larkin on 11 Apr 2010 00:42 On Sat, 10 Apr 2010 19:43:05 -0700 (PDT), brent <bulegoge(a)columbus.rr.com> wrote: >On Apr 9, 6:22�pm, John Larkin ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> On Fri, 9 Apr 2010 14:00:58 -0700 (PDT), whit3rd <whit...(a)gmail.com> >> wrote: >> >> >On Apr 8, 5:10�pm, John Larkin >> ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> >>ftp://jjlarkin.lmi.net/BreadBoards2.JPG >> >> >[shows a 74ACT04 with connection points] >> >> >But, what's the point of breadboarding a fast gate without the >> >required bypass capacitors on the power pins? �It's not gonna >> >behave like the final application does. >> >> There was a surface-mount cap between pin 14 and the solder blob on >> the copperclad. Looks like it broke, being tossed around in the >> breadboard bin for some number of years. Note that this is an RCA >> 74ACT04. I was astounded to see sub-ns rise and fall times, back when >> everybody thought that CMOS was slow. >> >> John > > >Have you thought about getting one of these ? I would love one > >http://www.lpkfusa.com/ We had one, at least a similar version. One of our customers gave it to us because they thought it was a silly PITA. We soon agreed. It's so much easier to lay out a proper plated-through board, multilayer if you need it, and order it quick-turn. John
From: Fester Bestertester on 11 Apr 2010 02:05 > That's a nice idea, but you do have to glue them down, and the glue > tends to pop off the copper. Is that the only reason you use Kapton (I presume it's 2-sided)? To hold parts in place better than CA or such?
From: John Larkin on 11 Apr 2010 12:09
On Sat, 10 Apr 2010 23:05:02 -0700, Fester Bestertester <fbt(a)fbt.net> wrote: >> That's a nice idea, but you do have to glue them down, and the glue >> tends to pop off the copper. > >Is that the only reason you use Kapton (I presume it's 2-sided)? To hold >parts in place better than CA or such? > No, it's just a one-sided insulator, but it stands up to solder. Kapton tape+copper tape = capacitor or transmission line Glues (hot melt, CA, epoxy) tend to not stick to copper for long. Solder is the best adhesive for copperclad. John |