555 Timer Circuit Short pulse Help

Dodgydave

Joined Jun 22, 2012
8,477
Ok, rocker switch to the right, pulse timer, rocker switch in centre pulse timer, rocker switch to the left no pulse, yes or no?
 

Thread Starter

Michael Knight

Joined Nov 5, 2015
90
Ok, rocker switch to the right, pulse timer, rocker switch in centre pulse timer, rocker switch to the left no pulse, yes or no?
Simple answer is "No" As in left also NEEDs a pulse, All three switch states need a pulse. :)
Rocker switch to middle (off) = Pulse
Rocker switch to left Device 1 (on) = Pulse
Rocker switch to right Device 2 (on) = Pulse
 
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Thread Starter

Michael Knight

Joined Nov 5, 2015
90
Photo on 2015-11-08 at 6.11 PM.jpg
I wonder if something like this will work? I found this circuit on Google that has an indicator state for output state High and Low. My thought was that perhaps the two states could be sent to our other "Timed" 555 circuit via the trigger input of this circuit from the rocker switches.??

This is the image I found online:
 
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ScottWang

Joined Aug 23, 2012
6,834
View attachment 94289
I wonder if something like this will work? I found this circuit on Google that has an indicator state for output state High and Low. My thought was that perhaps the two states could be sent to our other "Timed" 555 circuit via the trigger input of this circuit from the rocker switches.??

This is the image I found online:
Before you connecting the LED to the pin 3 , you should test that two R and two LEDs independently to make sure they won't light up when the power is upper than 9V, if they light up then you better in series with a diode for each LED and recalculate the values of R.
 

Thread Starter

Michael Knight

Joined Nov 5, 2015
90
Before you connecting the LED to the pin 3 , you should test that two R and two LEDs independently to make sure they won't light up when the power is upper than 9V, if they light up then you better in series with a diode for each LED and recalculate the values of R.
I did test out this circuit on it's own just wired to a 9V battery, I used a couple of 470R resistors for the two "R" resistors and the circuit works.
What I'm wondering is if it is possible to somehow use the two different LED states for pin 3 being either High or Low to send out to another timer circuit, (the one we have already worked out that sends the needed short pulse.) and have that generate the pulse for when my latching switches are in their "OFF" position.
 

Dodgydave

Joined Jun 22, 2012
8,477
Ok mike, try this circuit, extra diodes, resistors, and a transistor.

DSC_0043_622x600.jpg

With the switch in either left or right position you get your pulse from the capacitors as normal, when the switch is in the off state ( centre) the two diodes Da and DB wont conduct and the transistor will turn on via Rc and Dc, and will give a pulse to the555 timer.
 

ScottWang

Joined Aug 23, 2012
6,834
Ok mike, try this circuit, extra diodes, resistors, and a transistor.

View attachment 94318

With the switch in either left or right position you get your pulse from the capacitors as normal, when the switch is in the off state ( centre) the two diodes Da and DB wont conduct and the transistor will turn on via Rc and Dc, and will give a pulse to the555 timer.
Please don't forget to cut and compress to as 800x600, I already did this for you, next time don't forget again, thanks.
 

Thread Starter

Michael Knight

Joined Nov 5, 2015
90
Ok mike, try this circuit, extra diodes, resistors, and a transistor.

View attachment 94318

With the switch in either left or right position you get your pulse from the capacitors as normal, when the switch is in the off state ( centre) the two diodes Da and DB wont conduct and the transistor will turn on via Rc and Dc, and will give a pulse to the555 timer.
Thanks Dodgy dave, this one looks doable only I'm unclear on a few things in your diagram, I redrew it a little more clearly with some "?" marks.

20151109_071645_751x600.jpg



Mod edit:
You still not to compress to 800x600.
I compressed it from about 1.3Mb to 48Kb, it is close to 26:1.
 

Thread Starter

Michael Knight

Joined Nov 5, 2015
90
Dodgydaves last post looks really promising, I'm so going to try that today and post my results.... in the mean time I was also wondering about something like this?:
DTMF_TimerCircuitV3_Theory01LR.jpg
 

Thread Starter

Michael Knight

Joined Nov 5, 2015
90
No you have missed out Rc, and its pin 1 that goes to negative supply not pin 4, look at my drawing.
OK I did a more cleaned up version but I'm sure I'm missing a few things so if you could kind of fill in the blanks that would be awesome.... just incase I have it wrong or have missed something.

DTMF_PulseForDPDT_Rockers_LR.jpg
 

Dodgydave

Joined Jun 22, 2012
8,477
The circuit is correct upto pin 2 of the 555 timer,

then you need to have your timing resistor and capacitor on pins 6,7 as normal, supply pins 4,8 to positive, pin1 to negative, output on pin 3.
 

Thread Starter

Michael Knight

Joined Nov 5, 2015
90
The circuit is correct upto pin 2 of the 555 timer,

then you need to have your timing resistor and capacitor on pins 6,7 as normal, supply pins 4,8 to positive, pin1 to negative, output on pin 3.
Awesome Dodgydave, Take a look at this and see if it looks OK, if it all looks good then I can test this out and post a video with the results.
I think my timing 1M was lower i'll have to look at what I have on the breadboard ;)

DTMF_PulseForDPDT_Rockers_LR.jpg
 
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