What is the maximum Timer can i get ? - Page 2 - Electronic Circuits Projects Diagrams Free

aljamri · 23rd March 2008, 10:30 AM

Quote:

Originally Posted by audioguru

Two polarized electrolytic capacitors connected in series and back-to-back make a non-polar capacitor half the value.

negative-to-negative? like the attached config.?

Hero999 · 23rd March 2008, 01:53 PM

It doesn't make any difference whether you connect them negative to negative or positive to positive.

Anyway you shouldn't need an electyrolytic capacitor with the CD4521 as the delays you're talking about can be easily implemented with a ceramic capacitor which is non-polarised.

You really need a counter with more bits than 16 for the longer delay, I'd go for 24-bit minimum.

EDIT:
You could also try the 74HC5555.
http://www.standardics.nxp.com/produ...t/74hc5555.pdf

Some of these ICs are hard to find as MCUs have replaced them in many applications, here's the datasheet for the CD4536 which has a 24-bit counter.
http://focus.ti.com/lit/ds/symlink/cd4536b.pdf

Also it's still made.
http://www.supplyframe.com/partsearc...S/CD4536BDWRG4

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23rd March 2008, 01:53 PM	(permalink)
Hero999	It doesn't make any difference whether you connect them negative to negative or positive to positive. Anyway you shouldn't need an electyrolytic capacitor with the CD4521 as the delays you're talking about can be easily implemented with a ceramic capacitor which is non-polarised. You really need a counter with more bits than 16 for the longer delay, I'd go for 24-bit minimum. EDIT: You could also try the 74HC5555. http://www.standardics.nxp.com/produ...t/74hc5555.pdf Some of these ICs are hard to find as MCUs have replaced them in many applications, here's the datasheet for the CD4536 which has a 24-bit counter. http://focus.ti.com/lit/ds/symlink/cd4536b.pdf Also it's still made. http://www.supplyframe.com/partsearc...S/CD4536BDWRG4 __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez And http://www.silicontronics.com, same screen name as here. Last edited by Hero999; 23rd March 2008 at 02:25 PM.