I am looking for a simple bargraph circuit that will indicate how long a button is pressed. Full bargraph when button is held for 2 seconds. (adjustable down to 1 second) The leds will ramp up and down during the time the switch is closed and open.
The circuit should run from 12volts.
As simple as possible. I assume a 555 timer with a LM3914 ic will be needed.
The switch will be a standard TLP621 optoisolator connected to a computer.
This circuit will be used to indicate when corrections are sent to my telescope mount when it is tracking stars.
Thanks for any info you can provide.
Dwight
The circuit should run from 12volts.
As simple as possible. I assume a 555 timer with a LM3914 ic will be needed.
The switch will be a standard TLP621 optoisolator connected to a computer.
This circuit will be used to indicate when corrections are sent to my telescope mount when it is tracking stars.
Thanks for any info you can provide.
Dwight