Subject:
|
re: ztx614
|
Newsgroups:
|
lugnet.robotics.handyboard
|
Date:
|
Wed, 19 Mar 1997 09:51:06 GMT
|
Original-From:
|
Stefano Nardone <stefanon@SAYNOTOSPAMpromos.it>
|
Viewed:
|
2365 times
|
| |
|
|
> If I have interpreted the schematics correctly almost any npn can be used for
> the ztx614. The 614 simply provides ground for the IR transmitter with a
> collector current of about 3ma. The base current is set by the 10k R to about
> (5/10k) 0.5ma. If I have calculated f=1/2*pi*RC for the TOC5 enabled
> oscillator, then the frequency max of the IR output is in the kilohertz range.
I think it must better be a darlinghton and it must support enough current: if
you want to get 0.1A or more pulsed current in the IR led, the transistor must
have a rather high current gain, more than that of an ordinary npn trans (by
the way the base current is less than 0.5mA). Probably an N-MOS switch with the
right switching V and enough current (BS170?) can be better...
>
> This all means that almost any medium power npn can be used! I am
> building my own board and could not find the part either. I am going to
> finish my board tonight and I am substituting a 2N3904 for the ztx614.
8^) I too substitued it with an ordinary NPN transistor... but until now
haven't used the IR interface
regards
stefano nardone
******
**** stefanon@promos.it | stefanon@synapsis.it
*** tel. +39 81 7142222 | fax +39 81 645130
** http://www.synapsis.it/uw/stefanon/
*** talk: stefanon@posillipo.promos.it
**** snail-mail: Promos SIM spa, Via Stazio 5, I-80123 Napoli, Italy
******
|
|
Message has 1 Reply:
 | | re: ztx614
|
| (...) I just looked back to the IR transmitter schematic... The 1K res + RED LED you see there is for the only purpose of having a visible feedback of IR transmission. The IR Led and it's limiting resistor (if the case) will be connected in series (...) (28 years ago, 19-Mar-97, to lugnet.robotics.handyboard)
|
Message is in Reply To:
| | re: ztx614
|
| If I have interpreted the schematics correctly almost any npn can be used for the ztx614. The 614 simply provides ground for the IR transmitter with a collector current of about 3ma. The base current is set by the 10k R to about (5/10k) 0.5ma. If I (...) (28 years ago, 17-Mar-97, to lugnet.robotics.handyboard)
|
3 Messages in This Thread:
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
This Message and its Replies on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
