17 Feb
2010
17 Feb
'10
6:49 p.m.
Tony, I think you are being elitist, but not in an
evil, dismissive
Well, I have no desire to exclude anybody from learning about
electronics, that is for sure.
way but more in the (Monty Python-esque) "in MY
days we had to walk
uphill both ways in 10 ft snow-drifts" kind of way. :-) I can totally
see where you are coming from, but think you are a bit too dismissive
of the "kids". I will just argue that the kids will be alright, in
the end.
Hmmm.. When I was a kid I had various educational electronics kits. The
ones I liked the best, and the ones I learnt the most from were the
Philips EE series. OK, you didn't have to solder anything, but you did
get to handle real components, not little modules. And you built things
like Wein bridge oscillators, superhet radios, and the like.
I saw a modern electornics kit the other day in a shop. It proudly
proclaimed 'build .. .n FM radio...' Upon investigatio it appears that
there was an 'FM Radio Module' in the kit. All you had to do was connect
up the battery, a couple of switches and a speaker. That's not 'building
an FM radio'. Said Philips EE kits also had you making an FM radio. Using
an FET, a few bipolar transistors, a varicap diode, and so on.
Yes, breadboards are horrible, electrically. But everyone has to
start learning electronics somewhere and somehow, and solderless
breadboards allow students to try things quickly, blow stuff up, burn
OK, I;'ve been doing this for 30 years or more, but I find it a lot
quicker to solder somethign up that to use one of those breadboards. And
it's not hard to desolder things, make changes, experiment.
transistors etc, etc - I still have a board somewhere
with blackened
traces :-) It is the best way to teach. If you force students to
design, check and solder even simple low-speed circuits, they will
loose interest quickly.
The main problem is that those breadboard are terrible. It's not the
clock speed that matters, it's the swtiching time of the IC. Most modern
ICs have ouptus that switch so fast that when you combine them with the
stray capacitances on the breadboard and the relatively high impedance
power connections, you get power and ground lines bouncing all over the
place. Without a _good_ 'scope it's impossible to know why your circuit
doesn't work. If you stick to 4000 series CMOS you'll be alright, but
modern 74xxx familes are pushing it. Really pushing it.
-tony