I don't know why my Periodic ON-OFF Timer don't work. They are two CD4541.

[taotoon]

I don't know why my Periodic ON-OFF Timer don't work. They are two CD4541.

I don't know how Master Reset (MR) pin work.

LOW -> HIGH = stop oscillator, output unchange ?
HIGH -> LOW = start oscilator, reset counter, output change ?


I test by insert only the right chip. The output remain HIGH all the time.
I try to reset by apply V+ to MR pin, the output still HIGH.
I remove V+ from MR pin, the output still HIGH.

(The right chip set to Auto Reset when power on.)

 

[mneary]

Confirm that you have correctly identified pin 1 on the ICs. Looks backward to me.

 

[kchriste]

I try to reset by apply V+ to MR pin, the output still HIGH.
I remove V+ from MR pin, the output still HIGH.

You are using a pulldown resistor on the MR pin when you do this right?

 

[taotoon]

Confirm that you have correctly identified pin 1 on the ICs. Looks backward to me.

Yes Pin1 is top left.

 

[taotoon]

You are using a pulldown resistor on the MR pin when you do this right?

No. I use regulated 10V (7810). I jump that 10V to MR.
I will measure voltage at all pins again.

 

[taotoon]

C on pin 2 has a pole ?
My 0.1uF tantalum has a pole.

 

[audioguru]

Every Cmos oscillator that I have seen has AC across the capacitor. So a polarized tantalum capacitor won't work.

 

[taotoon]

Thank you. My project is currently pending for a long time. I will try non-polarize capacitor.

 

[KeepItSimpleStupid]

I didn't look carefully,but...

Cmos: all inputs must Be used.
Watch level triggered.
Watch edge triggered.