posouzeni schematu

Danhard danhard@volny.cz
Úterý Září 14 08:33:57 CEST 2004


Par slov od neautora :
Dobre, ma byt pouzita nejaka amplitudova modulace na 200 a 400MHz.
Pominuli nevhodnost amplitudove modulace a zvoleni frekvenci (kdy jedna je
primo druhou harmonickou druhe), tak me zajima zbytek "technickeho reseni":
- jak chce donutit pracovat obvody 74AS na frekvencich 400MHz ?
- jake chce pouzit krystaly (resp. rezonatory, protoze krystaly kmitajici na
1. harmonicke se delaji max. do cca 30MHz) ?
- jak chce zarucit odporem 47k pracovni podminky oscilatoru s 74AS04 ? (mozna
by si mel nastudovat neco o vstupnich proudech TTL logiky)
- jak chce budit vystup budit z dratu Tx+, kdyz je vedeni buzene
transformtorem a je DC plovouci ?
- jak ma byt stabilizovan pracovni bod vstupniho 74AS08 a celeho toho
podivneho filtru ?
- jake chce pouzit opticke infra komponety aby chodily na 400MHz ?
- jak chce dosahnout optickeho prenosu (svitim na sebe vysoce ucinnou infraled
na pindiodu a to jeste v plexikove trubicce jako optovodic na vzdalenost 30 mm
a takovyto "optoclen" ma prenos 2%) ?
atd.....

Danhard

> A slovo autora:
>
> No, I've not picutures of my devices becauses I have not build this
> device. I have just done its schematic. The infrared diode is a 10mA,
> 0.7V, 780nm to 1500nm. The infrared LED is a 15mA, 1.4V, 780nm to
> 1500nm. The wave length of the radiation of the both infrared device
> must be the same. For exemple, you can use 810nm for the diode and the
> LED. The infrared LED of the laptop computer must be adapted to the
> infrared diode of the desktop computer and vice-versa. I suggest you
> to use 2 different value of components group, one for each group to
> avoid interference between the two group even if the frequency is
> modulated. I chosse two quartz, 200MHZ and 400MHZ, because I wanted to
> modulated the frequency to avoid interference between the both
> emitters and the both receptors. I have choosen two different value
> because the filter let pass only a limited bandwidth of frequency. The
> difference between the both value is big. The range is 100 MHz
> approximately: it's not too high.
>
>
> >> Zdravim,
> >> muzete se prosim vyjadrit nekdo k tomuto schematu:
> >> http://www.electronics-lab.com/projects/pc/023/index.html
> >>
> >> Vypada to velmi lakave (100Mbit pojitko) ale ta konstrukce me osobne
> >> pripada podivna. Napriklad ze se lisi hodnoty soucastek v obou
> >> verzich, pritom by to mely byt totozne jednotky.
> >>
> >> No ja jen jestli to ma vubec cenu to zkouset bastlit a nebo jestli je
> >> to moc ocividne vyhozeny cas a penize...
> >>
> >> Diky Ondrej Tesar





Další informace o konferenci Hw-list