Adjustable delay switching of two relays alternately

Thread Starter

adjeiwaf

Joined Mar 4, 2015
2
I need to alternately switch two dry contacts /relays with variable time delays say 15mins or 20mins intervals .Think a 555 timer would work but will it be adjustable and have these two outputs?
 

#12

Joined Nov 30, 2010
18,224
One timer chip can not count both 15 minutes and 20 minutes at the same time. It will be adjustable if you build it to be adjustable. A 555 timer is really stretching to do 20 minutes. Better try a CD4020 counter chip.
 

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Thread Starter

adjeiwaf

Joined Mar 4, 2015
2
One timer chip can not count both 15 minutes and 20 minutes at the same time. It will be adjustable if you build it to be adjustable. A 555 timer is really stretching to do 20 minutes. Better try a CD4020 counter chip.
One timer chip can not count both 15 minutes and 20 minutes at the same time. It will be adjustable if you build it to be adjustable. A 555 timer is really stretching to do 20

. Better try a CD4020 counter chip.
kindly help e with cd 4020typicadiagram l
 

Reloadron

Joined Jan 15, 2015
7,501
You can as mentioned build your own circuit around a CD4020 timer chip and a Google of CD4020 Timer Circuits will yield dozens of circuits or as Mike mentioned, work from the data sheet. If this is for a commercial or industrial application another option is to simply buy a timer relay and a Google of Timer Relays will also bring up dozens of solutions which are plug and play. Since I have no clue as to your location I can't suggest manufacturers or model numbers of plug and play solutions.

Ron
 

#12

Joined Nov 30, 2010
18,224
I was designing circuits before the Internet was invented. I had to read the datasheet and teach myself how to connect chips. I assumed everybody did that. AmIright?
 

mcgyvr

Joined Oct 15, 2009
5,394
I was designing circuits before the Internet was invented. I had to read the datasheet and teach myself how to connect chips. I assumed everybody did that. Am I right?
No just old :p

Sadly.. The datasheet is usually the last thing people look at now a days..
Way too many forums/tutorials/youtube videos/blog posts,etc.. about EVERYTHING...
 

#12

Joined Nov 30, 2010
18,224
Let me clarify: Before the internet was invented, did everybody have to read the datasheet and teach themselves how to connect IC's?
 

Reloadron

Joined Jan 15, 2015
7,501
Let me clarify: Before the internet was invented, did everybody have to read the datasheet and teach themselves how to connect IC's?
Before the Internet was invented I had to find the data sheet. If the data sheet wasn't in the department library then I took a walk to the main company library. The real bitch was before the copy machine was available.

Ron
 
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