Delay generator

176

01:30:07

I designed this circuit to create a small delay between the input and the output.

The equation which describes the charging capacitor is :
Vc(t) = Vin . EXP(-t/(RC)) = Vin . EXP(-t/τ)
-Vc(t) : the voltage across the Capacitor.
-t : the time variable.
-R : the resistor value in Ohm.
-C : the capacitor value in Farads.
-τ : R×C, the time constant (Ohm times Farads gives us seconds).

Then i compare the capacitor voltage with an operational amplifier which allows me to adapt the "switch on" delay.

published 7 years ago

LeButch

7 years ago

Good. This might be usefull in some chases.

dkristal

7 years ago

Take a look at this http://everycircuit.com/circuit/5813139429130240

hurz

7 years ago

@blob, im not sure if you have planed this but, dont forget the output configuration of your OpAmps. Default is +-15V so you charge now from -15 upto 3V and switch while stop charge at 15V, which is, in this configuration luckily the same time, when start at 0 and stop at 5V. Was this taken into account?

LeButch

7 years ago

Ignore Hurz, he is just a troll.

hurz

7 years ago

For LeBitch the wich http://everycircuit.com/circuit/5168554495442944

snowfats

7 years ago

Not sure if it’d be a problem but because the RC part discharges through the same path it charges through meaning it takes the same time to fully charge and discharge. I have problems so I flipped the switch rapidly and found the output switched on much faster than the normal delay because the cap is still partially charged when it doesn’t reach its low level steady state

hurz

7 years ago

@blob seems to be gone...

blob

7 years ago

@hurz I know, i'm not that dumb ! I designed this circuit to make a delay from a sensor watching a mechanical movement. The fast repetition of the delay is not possible in this case. And dear, electronics is not a competition so you can keep your cynicism. Regards

hurz

7 years ago

You know what? What do you refer with this comment? Check my first comment and tell me what I have told you, but was useless to tell you! Im bad in mindreading as most humans.

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