Re: A few novice questions

On May 2, 3:27 pm, Tomás Ó hÉilidhe <t...@xxxxxxxxxxx> wrote:

Based on your last thread, I still cannot work out if you are real or
a troll. I'm answering this seriously.

I've been asking around and it seems that developers nowadays are
using different chips and transistors to the ones I know about. I know
about MOS transistors, but I've never used one.

Developers are using whatever their designs and cost budgets call for.
Bipolar transistors are slightly cheaper than FETs (at least, the ones
we buy in millions per month). If you just need to switch on a high-
current LED from a low-current GPIO, there is no compelling reason not
to use a PN2222, BC547 or similar bipolar transistor. If there was no
longer a use for these parts, they would no longer be manufactured.

1) What kinds of chips I should use with it, e.g. 74HCT family, or
4000 family, etc. ?

Selecting an external logic family depends on your circuit's Vcc, the
I/O level (CMOS, TTL, etc), the switching speed, the power consumption
etc. Many (I would guess most but I'm not sure about that) embedded
systems use no external discrete logic at all.

2) What transistors should I use a switches when I want to pass as
much as an ampere of current?

Depends a great deal. Is it AC or DC you're switching? What voltage?
Inductive or a resistive load? Would a relay be a better choice? How
much isolation do you need? Do you need to reverse the voltage?

Also, very quickly without getting into too deep a discussion, I'd
like to ask what microcontrollers I should be using? We've used the

For learning, you should be using something simple to use, with a
modern, clean architecture. I would recommend MSP430, AVR or ARM. Eval
hardware for the first two can be obtained for under $20; for the
second, under $40.

Neither PIC nor 8051 qualify as easy learning micros. However they can
be the right part for a real project.
.

Relevant Pages

  • Re: What is the state of Robotics Currently.
    ... estimate the amount of computing power to duplicate human intelligence ... We don't need to simulate transistors to create a computer, ... with neurons switching at 1000 times per second and 100 ... Large parts of the brain is filled with interconnects (white ...
    (comp.robotics.misc)
  • Re: Sony KV-35S45 Power Supply
    ... course blew the brand new switching IC. ... normal switching transistors, similar to those used in other Sony ... diode from the secondary side. ... This is a difficult circuit to troubleshoot ...
    (sci.electronics.repair)
  • Re: Aiwa schematics ... ?
    ... Has anyone got schematics for an Aiwa MX-Z9500MK that they could either ... I don't really know why they bother switching the ... Anyway, having found these transistors, I went ... filament volts, and display on the amp, but still no filament volts up the ...
    (sci.electronics.repair)
  • Re: Diode reverse protection and current limiting.
    ... another SCR across it with a capacitor in series. ... A more modern design might have transistors cycling on and off to control ... If you are thinking of any kind of switching regulator, ...
    (sci.electronics.design)
  • Re: Recommend transistor?
    ... >> switching times too, because BJT tend to be pretty slow. ... To me 5A/20V sounds more like the output of an audio power ... The transistors for both applications might be quite dissimilar, ...
    (sci.electronics.design)