Making your own board

[ojhspyro89]

ok well i have another thread http://forums.spudtech.com/topic.asp?TOPIC_ID=7557 there that is really waht i want but ill explain some here.


I want a board for my bko that is unlimited and based off a 555 timer. Id like adjustable debounce and dwell and thats bout it.

I can solder and do just bout anything and i have bunches of electric components in my basement in this huge toolbox that i was givin. I figure i could give some use to it.


Check out the thread because its ALOT more thorough and probly makes more sense.

[Joni]

I've heard that the problem with 555 timers is that you can't be really sure of the timing, since the timing is dependant on capacitators and resistors. Resistors aren't that accurate to begin with (most have 10% tolerance), and the resictance is dependant on temperature, meaning that you might have to retime it on a cold day, compared to a hot day.

[shatter_storm]

spudtech's forums arn't open to nonmembers - I can't view the post. Maybe you could copy the contents over to here?

I've heard that the problem with 555 timers is that you can't be really sure of the timing, since the timing is dependant on capacitators and resistors. Resistors aren't that accurate to begin with (most have 10% tolerance), and the resictance is dependant on temperature, meaning that you might have to retime it on a cold day, compared to a hot day.

While you can get resistors with lower tolerance and better temperature resistance, the problem really lies with getting all the logic just right to actually use a 555 timer in that manner. I'm no sparky, but I *really* wouldn't want to do something like an uncapped board with jumper-set debounce and dwell in hardware. I'm not sure you could pull it off with just a hobbiest's knowledge of circuits and IC's.
You're better off learning how to program a microcontroller so you can actually do things like debounce and dwell in software.


Now, if you wanted to make a FA board with adjustable rate, that'd be plenty easy with a 555 timer, some protoboard and parts found in a toolbox.

[purple]

Not only is the timing in a 555 suspect, but you'd also need to add a 741 Op amp since the 555 cant handle the current load of activating most kinds of solenoid. Board design/layout is also a very difficult art that would require programs like Pspice to layout and test the design. Also, you'd need a dark room, overhead projector, copper clad board and several etching chemicals to actually make the board, then a drill press, etc etc etc. Doing boards like this on one hole island project board is a very very very time consuming and usually pointless exersize.

sorry to rain on your parade :)

Do what you think is right, but keep this in mind

Purple