Cmos-precision-programmable-laboratory-timer


Posted on Oct 18, 2012

The time base is first selected with Sl set for seconds or minutes, then units 0-99 are selected on the two thumbwheel switches S4 and S5. Finally, switch S2 is depressed to start the timer. Simultaneously, the quartz crystal-controlled divider circuits are reset, the ICM7250 is triggered and counting begins.


Cmos-precision-programmable-laboratory-timer
Click here to download the full size of the above Circuit.

The ICM7250 counts until the preprogrammed value is reached, then, the value is reset, pin 10 of the CD4082B is enabled, and the buzzer is turned on. Pressing S3 turns the buzzer off.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

9 V NiCd or NiMH accumulator charger
Precise One Shot Circuit
Design a esthetic and energy-conserving acousto-optic controlled lighting lamp of corridor
usb joystick
compressor
line following robot sensor
Avenger Sebring Coupe Stratus Coupe 1999 2006
12 V High current regulator
psmd
Discharge After the memory circuit



Top