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Sci.Electronics.Basics is a worldwide Usenet news group that is used to discuss basic electronics questions.
We found 140 threads matching "ttl"
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The most relevant threads are listed first
TTL input circuit to drive diode
Gary H - 2006-11-22 20:45:00
Hi. I need a little help with something that should be pretty basic. I
have a control board that has a TTL output to turn on and off a laser. The
laser is nothing more than a diode that consumes about 60mA. So, I want to
be able to turn the diode on or off with the TTL output. I don't rea...
Re: ULN2803A (darlington array) anyone know what I'm doing wrong?
Don McKenzie - 2006-10-04 16:14:00
Ben wrote:
> I'd need 8 transistors, so a single chip that does the job seemed like a
> good idea.
Spot on Ben,
good work.
Don...
--
Don McKenzie
E-Mail Contact Page: http://www.dontronics.com/e-mail.html
Micro,TTL,USB to 1.5" color LCD http://www.dontronics.co...Re: Is it possible to multiply resistance?
Don McKenzie - 2006-08-25 16:03:00
randomname wrote:
> I know resistors in series simply add up... but is there any way to
> mulitply resistance?
>
> eg: can I take a 10k pot and make it work as if it were a 100k pot?
>
> Thanks,
> -sam
in a word, NO
Don...
--
Don McKenzie
E-Mail Contact Page: ...Re: microprocessor circuits
Don McKenzie - 2006-10-28 15:28:00
venkatsr wrote:
> Hi ,I would like to do simple but interesting circuits using
> microprocessors
> Is it possible without a microprocessor trainer kit ?
http://www.dontronics.com/dt006.html
you can build your own version if this suits, as all the info is there,
and demo version basc...MOSFETs and PWM
Randy Day - 2007-02-24 13:05:00
I've built some TTL motor/relay controllers
out of NPN transistors in a Darlington
configuration, and I'm considering using
mosfets instead.
+V
|_
- )|
^ )| relay
|_)|
|
...Simple amplifier: simulation & real world do not agree
Jenalee K. - 2006-09-27 11:45:00
I wanted to amplify a TTL-level 1MHz square wave a bit so that it can
be used as a clock for a CMOS counter running from 9V. According to
LT-Spice the circuit below works fine, but the real world does not
agree (at all). Actually I measured a cut-off frequency of 165kHz and
at 1MHz not much is l...Re: Expected voltage output of the PIC12F683.
Tim Auton - 2006-08-27 21:18:00
Mr. J D wrote:
> Eeyore wrote:
> > "Mr. J D" wrote:
> >
> > > I bought a pre-programmed PIC12F683,
> > > http://www.microchip.com/stellent/idcplgidcplg?IdcService=SS_GET_PAGE&node
Id=1335&dDocName=en010115
> > > , and was wondering what the voltage to amperage output expectan...Simple SD Interface
FyberOptic - 2010-01-06 19:36:00
Hi folks. Hopefully my post won't get lost in all the spam I noticed
in this area!
Anyhow, I want to do something fairly simple, but I want the advice of
someone who actually knows more about this stuff to make sure I don't
do something wrong that I'm not taking into account.
Basically I w...1PPS and 1 PPM signals driving
nds - 2006-08-24 02:54:00
I have a TM4 GPS unit gives o/p as 10 MHz sine wave, 1PPS , 1PPM
signals (100 ms on time squre wave)...
I would like to make the Mulitple of this signals ...
will u suggest me which IC's I should use as a Buffer or which give
multiple o/p
My specific requirement of ic that i should have 50 ...Re: RS422 RJ45 loopback cable
Don McKenzie - 2006-10-20 19:36:00
mike7411@gmail.com wrote:
> I created an RS422 RJ45 loopback cable by connecting pin 1 to pin 8 and
> pin 4 to pin 5.
>
> I also connected a few of the other pins that aren't used since it made
> it easier to line everything up into an RJ45 plug.
>
> However, when I type a letter, ...Re: Generate -+5V from 12V
Jon Kirwan - 2009-06-08 21:20:00
On Mon, 8 Jun 2009 17:36:08 -0700, "BobW"
wrote:
> "Jon Kirwan" wrote in message
> news:7c6r25p5s7kij3qo2dgpbliciqck0qkrbh@4ax.com...
> > On Mon, 8 Jun 2009 22:29:26 +0100, "ian field"
> > wrote:
> >
> > >
> > > 121
> >
> > Aka freenews.netfront.net
> >
> > Got it w...Re: Home-use microcontroller purchase
2008-01-13 11:54:00
Tom2000 writes:
> I like the idea of micros that you can program with free development
> systems and no requirement for dedicated programming hardware such as
> the Picaxe that Dave mentioned above.
That's why I like the R8Cs. They only need a serial link (TTL,
auto-baud-detect) to p...Re: 4 PC printer ports
petrus bitbyter - 2006-10-30 18:19:00
"Randy Day" schreef in bericht
news:ubv1h.230457$R63.31804@pd7urf1no...
> I'm wondering if there are any DIY projects
> for putting 4 parallel ports on an ISA or
> PCI card. I have a use for 4 ports in one
> machine, and I can't find too many commercial
> products like this any more...Re: do 16-input nand gates exist?
whit3rd - 2009-03-31 15:56:00
On Mar 28, 4:24=A0pm, panfilero wrote:
> I've been looking on digikey and on mouser and I can't find them...
> but does anyone know if 16input nand gates exist,
They used to exist (one gate delay and sixteen NAND inputs),
in the form of TTL "expandable gates"; SN7423, SN7455, SN7460
and...Re: HCT/TTL output current and supply current
Grant Stockly - 2007-10-25 19:39:00
On Oct 25, 12:32 pm, Rich Grise wrote:
> On Thu, 25 Oct 2007 00:30:04 -0700, Grant Stockly wrote:
> > I am trying to compare some standard series and LS parts to HCT parts.
>
> > I don't understand how the maximum ratings are calculated.
>
> > For example, the Phillips data sheet f...Cursed
Walt Fles - 2007-04-26 16:37:00
A princess walked into Radio Shack holding a frog. And she said to
the sales person,
"can you help me with this, my prince got turned into a frog"?
So the salesperson sold her a TTL 7404.
...pulse counter
George Herold - 2010-03-23 14:55:00
I want to count TTL pulses from a PMT. (There is already some pulse
shaping and discriminator electronics between the PMT and output.)
The TTL pulses have a fixed width of 300ns and a rate from 10 Hz to
several hundred kHz (coming at random times). In the good-old-days
all the frequency counte...Re: VGA 15 pin/9 pin Multisync=standard?
Sambo - 2007-03-03 12:54:00
SixteenThirtytwo wrote:
> I'm a little confused about the VGA and Multisync computer monitor
> standard.
>
> I know that 15 pins are most common, the pinout being as follows:
> http://www.technick.net/public/code/cp_dpage.php?aiocp_dp=pinconvid_vga_15pin
> I assume this is the pinout wh...Re: design help
RST Engineering (jw) - 2009-02-25 12:23:00
> What if you troll the troll trollers ?:-)
>
> What is that called?
>
> ...Jim Thompson
TTL?
Jim
...Voltage Regulator to IC
2006-10-28 13:00:00
If I am using a voltage regulator to bring a voltage down from 9 to 5
volts should I still put a capacitor before a TTL IC to smooth out the
current?
...Looking for old TTL chip...
Impmon - 2006-11-06 01:24:00
Part number 74256 2-of-8 addressable latch with reset and enable.
If there somewhere that still has those in stock at reasonable cost?
Or some substitute that would work?
--
When you hear the toilet flush, and hear the words "uh oh", it's already
too late. - by anonymous Mother in Austin,...Re: Supply dependent voltage reference?
MRW - 2006-11-29 17:51:00
Another question popped out regarding this topic. If I were planning on
using the voltage divider & voltage follower setup as my half-supply
source, what op amp parameters should I check? Will this have a similar
fan out characteristics that CMOS or TTL devices have?
...Re: When should decoupling capacitors be used.
2007-01-18 05:46:00
On 17 Jan 2007 13:15:56 -0800, "hybrid_snyper"
wrote:
> Hi all,
>
> A quick question when and where should i use decoupling capacitors.
> Circuits that i have built at uni have always been giving to us and
> there are often these decoupling capacitors but it is never be
> explained why ...Re: Substituting a digital pot for a mechanical pot in an AC voltage control circuit
eljainc - 2008-05-02 14:23:00
Is there any AC motor controller that is computer controlled? (RS-232/
USB or TTL)
I guess the Maxim/Dallas parts won't work.
I see that even AD digipots wont work (some will work with 10-15VAC,
but not higher)
...Simple analog to digital conversion??
2007-05-19 02:42:00
Hi all,
I'm looking for the *simplest* way to convert a 3-state analog input
(-5V, 0V, or +5V) into a 2-channel TTL output, as shown in the
following truth table:
Input Out 1 Out 2
------- -------- --------
-5V L H
0V L ...Re: 5V Logic Hi question
Anthony Fremont - 2007-04-03 15:13:00
Jay wrote:
> How close to 5V should a logic HI be? Is there any plus or minus
> deviation from 5 volts allowed?
Depends upon the parts family. CMOS want .7 * Vcc (3.5V), Schmidt inputs
often want to see .8 * Vcc (4V). TTL will let you get away with as little
as 2V. Your best bet is to ...Re: Problems about pic thermometer
Randy Day - 2009-03-04 18:19:00
> Thank you for answering me.
> Firstly, the address of datasheet of ADC converter is
> http://www.datasheetcatalog.com/datasheets_pdf/M/C/1/4/MC14504BCP.shtml.
That's not an ADC, that's a TTL/CMOS level
shifter. Why do you need one of those?
> Secondly, the part number of LCD is PMC...Re: Question: Learning How To Use Hand Held Oscilloscope
Chris L - 2007-11-18 18:04:00
On Nov 17, 9:00 pm, Peter Bennett wrote:
> On Sat, 17 Nov 2007 15:51:49 -0800 (PST), Chris L
> wrote:
>
> > Can the below information solve the problem?
>
> > Christopher Lusardi
>
> > The Operator's Manual says:
> > Product Standards and Specifications
>
> > Model ...Re: help me about 555
2008-09-04 19:39:00
On Thu, 4 Sep 2008, Yukio YANO wrote:
> E.persia wrote:
> > hi
> > I have a project that is connected with the famous 555 timer
> > I want ask you if you know a newwer chip with the better feature ...
> > this is very urgent to me
> > thank you all!
>
> I came across a 555 chip wit...Unindentify optocouple
mowhoong@hotmail.com - 2007-02-21 20:08:00
I need to replace some optocouple ( round shape plastic casing ). The
optocouple which trigger a triac and control by a TTL IC, there are
printing on the optocouple "MOD 725", i had desolder some good
optocouple and measure both side with two output lead, the DMM show
infinity in resistance,i co...Need Ideas for addressable register IC
Ken Fowler - 2007-02-05 17:54:00
I need some help.
After several years retired and many more years away from cobbling together TTL and field
programmable parts,
I'm trying to get my hands dirty again on a project.
I am trying to design a replacement UART module for a radio designed about 25 years ago. The
original
module...Coil driving
Nuby - 2007-10-13 13:58:00
What's wrong with this picture?
TTL control lines with small current sinking capability (say 20ma)
need to activate electromagnetic coils (50VDC, 300ma). Each control
line gates an SCR which runs Vcc into a coil. The group of coils has
a common disable in the form of a big relay that cuts th...Re: 0-99 Binary to BCD converter
2007-04-04 05:24:00
On 03 Apr 2007 12:24:22 -0400, DJ Delorie wrote:
>
> feebo writes:
> > lots of answers from other people here (mostly jokes, right?)... but..
> > the best way to do it is with 2x 74LS185 - they are designed exactly
> > for this job.
>
> The 74LS185 is a ROM chip, pre-programmed with...Re: Question about led flasher circuit
Michael Black - 2007-04-10 17:12:00
(hc04@btinternet.com) writes:
> I want to build some circuits from
>
> http://ourworld.compuserve.com/homepages/Bill_Bowden/page10.htm
>
> About 1/3 down there are 4 1.5V led flasher circuits.
>
> The first one uses a 74hc04 hex inverters chip.
>
> I have tried to use a chip ...Re: Generate -+5V from 12V
Jon Kirwan - 2009-06-08 22:39:00
On Mon, 8 Jun 2009 18:29:07 -0700, "BobW"
wrote:
> "Jon Kirwan" wrote in message
> news:otdr25hb5fp274cm40s4pbplte161oa8vu@4ax.com...
> > On Mon, 8 Jun 2009 17:36:08 -0700, "BobW"
> > wrote:
> >
> > > "Jon Kirwan" wrote in message
> > > news:7c6r25p5s7kij3qo2dgpbliciqck0qkr...Re: FM transmitter does not work on breadboard
BobG - 2006-08-30 13:44:00
chriswilliams wrote:
> I have armed an FM transmitter on breadboard but for some reason it
> does not work. I have checked wiring and components and all seems to
> be OK.
=================================
'Armed' is a funny word to use. Like 'Cocked'... like you have a static
hi or lo leve...Re: Driving LEDs with higher current or from a higher positive voltage.
Peter Bennett - 2006-12-19 13:02:00
On 18 Dec 2006 18:14:33 -0800, "Manj" wrote:
> Thanks Chris!!!Can you explain me why do we put a resistor from base to
> ground?Is it necessary?Is there a N-P-N transistor array (preferably
> surface mount)avilable, becas I need to construct a led matrix of 8X8
> and placing single transist...driving a relay with 24vdc low current IO
CptDondo - 2007-02-14 14:10:00
I have a board with a bunch of TTL-level IO. It can handle a few
milliamps (about 10) per IO.
I would like to be able to control 120VAC loads with this board. The
relay bank I have needs 50 ma to drive each relay; too much for my
little board.
Does anyone know of a ready-made inexpensi...Re: how to find compatible component ? search made me bleary brained
Eeyore - 2007-11-30 12:15:00
robb wrote:
> so i have a **DM7496** (DIP16) that is fried (obsolete), and i
> need compatible replacement
The vital piece of info*7496*. DM is simply a manufacturer specific prefix.
This means it's a standard 74 series TTL part. These are still widely available
in more modern ver...Re: H-bridge with Pic
John Popelish - 2006-11-04 22:07:00
lerameur wrote:
> John Popelish wrote:
> > I would start by eliminating any possibility that the PIC is
> > involved in the problem, by just jumpering the 3 inputs to
> > either +5 or ground, to check out the bridge driver.
> > Don't forget to include a bypass capacitor between the 12
>...