4541 timer question.

[muddasserniaz]

i have built this 4541 single shot timer ranging from 15m to 8hrs. The output remains low and goes high after set time.

How can i get notification that oscillator /circuit is working properly when the timer starts.???

regards

 

[k7elp60]

I don't understand why you have a resistor from pin 6 to ground. The spec sheet says it should be at 0 for timer operational or 1 for master reset. Since you have it programmed for power up reset and single cycle operation, you can assume with the output a 0 it is functioning properly when you apply power. I would recommend that you only change the dip switch setting for capacitor selection when the power is off.

 

[Roff]

You could monitor the internal clock with a small MOSFET (2N7000, 2N7002), an LED, and a current-limiting resistor. Gate to pin 3, source to GND, drain to LED-resistor series combo, other end of LED-resistor to VCC.

 

[muddasserniaz]

Accuracy and Frequency questions!!

You could monitor the internal clock with a small MOSFET (2N7000, 2N7002), an LED, and a current-limiting resistor. Gate to pin 3, source to GND, drain to LED-resistor series combo, other end of LED-resistor to VCC.

thanks ron , oscillator monitoring led is working great with 2n7000.. !!

i have some more questions regarding 4541 operation.. plz help!!

1) what's the lowest frequency possible/recommended , although datasheet says the fx should be between 1khz and 100khz i have used it at 1hz and its still working ....but when fx is lower than 1 it is not working.

some say that 4541 can be used for timing delays of days but i am not sure how it can be achieved without fx lower than 1hz.

2) keeping in view the component tolerances how can i achieve best accuracy??

 

[Roff]

thanks ron , oscillator monitoring led is working great with 2n7000.. !!

i have some more questions regarding 4541 operation.. plz help!!

1) what's the lowest frequency possible/recommended , although datasheet says the fx should be between 1khz and 100khz i have used it at 1hz and its still working ....but when fx is lower than 1 it is not working.

some say that 4541 can be used for timing delays of days but i am not sure how it can be achieved without fx lower than 1hz.

2) keeping in view the component tolerances how can i achieve best accuracy??

Sorry, I've not used the 4541. Maybe someone else can help.

 

[k7elp60]

For accurate long time delays I would use a CMOS 555 as you can use up to about 20M of resistance for timing. But use a good quality film capacitor. You could still use the 4541 divider. I have used the 555 and cascaded 4060 14 bit counters for extreemly long delays.

 

[audioguru]

The datasheet for the CD4541 says you can operate the clock oscillator as slowly as you want. Then you can use its divider to divide by up to 65k.

 

[mvs sarma]

......
How can i get notification that oscillator /circuit is working properly when the timer starts.???

regards

Hi
i understand your doubt as how to know the cct is functioning or power failed --something-- in fact you might have notices that 4541 can output either Q or Q*
if you select by defining the select pin you get a high sinal when the timer is ON . Hope this helps