P
petrus bitbyter
Guest
"John Fields" <jfields@austininstruments.com> schreef in bericht
news:asari1huban1675d311qo85na5o71ivkiv@4ax.com...
Once you have a 555 clock running you can hook up an old CD4013B like drawn
below. This type of components runs on power supplies from 3 to 20V. Of
course you have at least one problem left as these type of components can
sink only a few mA of current. So your LEDs will be pretty dim or you have
to use high efficiency LEDs. The series resistors can also be much lower
then calculated as the outputs have an internal resistor inside. The best
thing you can do is using an extra IC, a CD4050B. This one contains six
buffers which are able to sink enough current to drive a LED.
Vcc 3-20V +-----+-----+-----+-----
| | | |
.-. .-. .-. .-.
| | | | | | | |
| | | | | | | |
'-' '-' '-' '-'
| | | |
| | | |
V V V V
- - - -
| | | |
| | | |
| +--------+ |
| | | |
| | +--------------+
.----. | | .---- | |
+-----|D0 Q|---+--|-----|D1 Q|---+ |
| | _| | | _| |
| +--|> Q|o-----+ +--|> Q|o-----+
| | '----' | '----' |
| | CD4013B(a) | CD4013B(b) |
Clock | | | |
----------+-----------------+ |
| |
+-----------------------------------+
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de
petrus bitbyter
news:asari1huban1675d311qo85na5o71ivkiv@4ax.com...
On Sat, 17 Sep 2005 18:09:58 -0500, John Fields
jfields@austininstruments.com> wrote:
Aaarrghhh!!!
I forgot the fourth LED, and the 7555's RESET is negative true...
7555
+-------+
+--|TH OUT|O-+
| |___ _| |
+-O|DIS R|O----Vcc
| +-------+ | Vcc
| | Vcc |
+----[POT]<---+ +-----+ | [100K]
| | | _| | |
| 1M | +----|D Q| | |
| | | | _| | |
[1ľF] +------|> S|O------+----+
| | | | _| | | |
| | | +--|Q R|O--+ | [0.1ľF]
| | | | +-----+ | | |
| | | | HC74/2 | | GND
+-[<LED]--[R]-----+ | |
| | | | | |
| | | | +-----+ | |
| | | +--|D | | |
| | | | _| | |
| +------|> S|O------+
| | | | _| | |
| | | +--|Q R|O--+ |
| | | | +-----+ | |
| | | | HC74/2 | |
+-[<LED]--[R]-----+ | |
| | | | | |
| | | | +-----+ | |
| | | +--|D | | |
| | | | _| | |
| +------|> S|O--+ |
| | | | _| | |
| | | +--|Q R|O------+
| | | | +-----+ | |
| | | | HC74/2 | |
+-[<LED]--[R]-----+ | |
| | | | | |
| | | | +-----+ | |
| | | +--|D | | |
| | | | _| | |
| +-|----|> S|O--+ |
| | | _| |
+-[<LED]--[R]---+----|Q R|O------+
| +-----+
GND HC74/2
Also, a better way to run the LEDs would be off of the Q's. The
starting (and running) sequence could be made the same as if they
were being driven by the Q's by complementing the SETs and RESETs,
but there'd no LED loads on the Q's and, consequently, no problem
with logic input thresholds being load dependent.
Wire it up the way it's shown and if you have problems with it, post
back and I'll be happy to help you get it right.
---
More problems.
HC74's aren't supposed to run on 9V, so you'd have to use something
like a 78L05 to get that 9V down to 5V if you used HCMOS, and
recalculate the LED series R's.
--
John Fields
Professional Circuit Designer
Once you have a 555 clock running you can hook up an old CD4013B like drawn
below. This type of components runs on power supplies from 3 to 20V. Of
course you have at least one problem left as these type of components can
sink only a few mA of current. So your LEDs will be pretty dim or you have
to use high efficiency LEDs. The series resistors can also be much lower
then calculated as the outputs have an internal resistor inside. The best
thing you can do is using an extra IC, a CD4050B. This one contains six
buffers which are able to sink enough current to drive a LED.
Vcc 3-20V +-----+-----+-----+-----
| | | |
.-. .-. .-. .-.
| | | | | | | |
| | | | | | | |
'-' '-' '-' '-'
| | | |
| | | |
V V V V
- - - -
| | | |
| | | |
| +--------+ |
| | | |
| | +--------------+
.----. | | .---- | |
+-----|D0 Q|---+--|-----|D1 Q|---+ |
| | _| | | _| |
| +--|> Q|o-----+ +--|> Q|o-----+
| | '----' | '----' |
| | CD4013B(a) | CD4013B(b) |
Clock | | | |
----------+-----------------+ |
| |
+-----------------------------------+
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de
petrus bitbyter