Full wave square wave generator from dual led flasher.

I found this schematic of a dual led flasher in a
bookhttp://xedox.de/blinker.htm Could I eliminate the two led's and and
connect the cathode of each to the anode of the other and get a full
wave square wave output?

 

[ehsjr]

ngdbud@hotmail.com wrote:

I found this schematic of a dual led flasher in a
bookhttp://xedox.de/blinker.htm Could I eliminate the two led's and and
connect the cathode of each to the anode of the other and get a full
wave square wave output?

I don't know what you have in mind when you say "a full wave
square wave".

You'll get the square wave at the emitter of either of the
transistors in the diagram at the site you mentioned.
Don't change the circuit the way you mentioned
For more information, see:
http://artscool.cfa.cmu.edu/~winkler/60422A/Multivibrator/multivibrator.pdf

You'll find the square wave diagram in figure 3.7.
It will vary from 0 volts to Vcc

Ed

 

[Jasen Betts]

In article <1124605702.544955.262670@z14g2000cwz.googlegroups.com>, ngdbud@hotmail.com wrote:

I found this schematic of a dual led flasher in a
book http://xedox.de/blinker.htm

it's not the best circuit... it wastes 6 of the 9v running the oscilator.

Could I eliminate the two led's and and
[...]
get a full wave square wave output?

if you omit the LEDS (replace them with wire) you could get a square-ish wave
that varies most of the way from 0 to 9v from the collector of either
transistor (the junction of the 330 ohm resistor and 47uF capacitor

I say square-ish because that type of oscilator tends to slowly relax towards
the centre voltage before switching - probably why it's called a relaxation
oscilator

if you want to flash leds replace the 330 ohm resistors with 1K and put the
LEDS in parallel with them and run the whole thing off 3V.

--

Bye.
Jasen

 

[ehsjr]

Jasen Betts wrote:

In article <1124605702.544955.262670@z14g2000cwz.googlegroups.com>, ngdbud@hotmail.com wrote:

I found this schematic of a dual led flasher in a
book http://xedox.de/blinker.htm


it's not the best circuit... it wastes 6 of the 9v running the oscilator.


Could I eliminate the two led's and and

[...]

get a full wave square wave output?


if you omit the LEDS (replace them with wire) you could get a square-ish wave
that varies most of the way from 0 to 9v from the collector of either
transistor (the junction of the 330 ohm resistor and 47uF capacitor

I say square-ish because that type of oscilator tends to slowly relax towards
the centre voltage before switching - probably why it's called a relaxation
oscilator

Astable multivibrator is more specific

if you want to flash leds replace the 330 ohm resistors with 1K and put the
LEDS in parallel with them and run the whole thing off 3V.

And kiss your leds goodbye.
Ed

 

[Jasen Betts]

In article <vnnPe.4169$SW1.542@trndny09>, ehsjr wrote:

Jasen Betts wrote:
In article <1124605702.544955.262670@z14g2000cwz.googlegroups.com>, ngdbud@hotmail.com wrote:

I found this schematic of a dual led flasher in a
book http://xedox.de/blinker.htm


it's not the best circuit... it wastes 6 of the 9v running the oscilator.


Could I eliminate the two led's and and

[...]

get a full wave square wave output?


if you omit the LEDS (replace them with wire) you could get a square-ish wave
that varies most of the way from 0 to 9v from the collector of either
transistor (the junction of the 330 ohm resistor and 47uF capacitor

I say square-ish because that type of oscilator tends to slowly relax towards
the centre voltage before switching - probably why it's called a relaxation
oscilator

Astable multivibrator is more specific

there are other forms of astable multivibrator that rely on different
mechanisms for the oscilation.

if you want to flash leds replace the 330 ohm resistors with 1K and put the
LEDS in parallel with them and run the whole thing off 3V.

And kiss your leds goodbye.
Ed

never happened here. there's always some drop in the transistor...


Bye.
Jasen