Hi guys, i just rescently checked the posted thread trying to find a way to make this project, but too complicated solutions for a simple yet easy task, a timer triggering an event every 2 hours in this case, i need to move an AC motor through a 6/12V relay for about 6sec, it is s imple egg tray turner in a small incubator, so i´ve allready desing the motor time controled relay, but i need the trigger to activate that circuit every 2 hour, i guess the 555 can do the job but if any of you have any easy idea please let me know.

here is the actual motor relay cotroler 6sec (programmable), allready done, now i need to replace the actual switch with a time trigger, any sugestion? cheers.

 

The 555 alone won't work for a 2hr cycle - you'll need to add a timer such as 4060 or 4017. The 555 will oscillate to provide a clock signal and the counter divides it down to give you a much longer interval.

 

120min is too long for a 555. Look into a 4521 or other similar osc/divider chips

 

use cd4060 timer chip.


http://www.zen22142.zen.co.uk/ronj/24h.html

 

I recommend the approach that Dodgydave posted to give the 2 Hr signal.
Use that signal to trigger a 555 timer to give the 6s pulse, or do you already have that timer?

 

If using 4060 IC:
2 hours = 7200 sec, using 14 th stage, divide by 8192 gives a clock period T of .879 sec. T= about 2 Cx Rx; Rx = 1 M, Ox =.44 uF or Cx = .5 uF then Rx = 880 k. Use a pot & resistor to give about 1 M for Rx & adjust as needed to get pot in range. Check stage 4, pin 7 for a period of 7 sec. At count 8192 stage 14 goes high resetting 4060 & triggering 555. Note, .01 uF cap is not needed as soon as 14 goes high, 4060 is reset giving 555 a really short neg pulse.
A 555 can be used for a 2 hour clock but a verry low leakage cap. is needed. I have gone to 3 hours.

 

There is an after market programmable 555. It is designated CS555. It has internal dividers with a maximum division of 10E6. I have some and the programmer. It is a cmos device so an external driver (transistor) would be necessary to energize a relay or such. I would be happy to program one for you and provide a driver.

 

Guys i really apreciate your kindly help, i´ve been the whole day browsing the webb for a solution and all of you made me see i was in the wrong direction, that´s why is important to study and be informed about devices and uses, i made my acknowledgement to all of you, Thanks a lot, now i will reorder my ideas with your suggestions.

 

There is an after market programmable 555. It is designated CS555. It has internal dividers with a maximum division of 10E6. I have some and the programmer. It is a cmos device so an external driver (transistor) would be necessary to energize a relay or such. I would be happy to program one for you and provide a driver.

That is really cool. I haven't seen those before. $35 for a programmer - almost the price of a pickit3.

 

If using 4060 IC:
2 hours = 7200 sec, using 14 th stage, divide by 8192 gives a clock period T of .879 sec. T= about 2 Cx Rx; Rx = 1 M, Ox =.44 uF or Cx = .5 uF then Rx = 880 k. Use a pot & resistor to give about 1 M for Rx & adjust as needed to get pot in range. Check stage 4, pin 7 for a period of 7 sec. At count 8192 stage 14 goes high resetting 4060 & triggering 555. Note, .01 uF cap is not needed as soon as 14 goes high, 4060 is reset giving 555 a really short neg pulse.View attachment 80650
A 555 can be used for a 2 hour clock but a verry low leakage cap. is needed. I have gone to 3 hours.

Thanks a lot Bernard for your attention, i will go first to the e-shop and will buy this IC and then will test your idea, let you know how it work, Thanks again.

 

I recommend the approach that Dodgydave posted to give the 2 Hr signal.
Use that signal to trigger a 555 timer to give the 6s pulse, or do you already have that timer?

I´ve allready have the 6s timer relay controlled i need to develop the 2 hours trigger just that now i have couple ideas with a diferent IC 4060 thanks Sir.

 

If using 4060 IC:
2 hours = 7200 sec, using 14 th stage, divide by 8192 gives a clock period T of .879 sec. T= about 2 Cx Rx; Rx = 1 M, Ox =.44 uF or Cx = .5 uF then Rx = 880 k. Use a pot & resistor to give about 1 M for Rx & adjust as needed to get pot in range. Check stage 4, pin 7 for a period of 7 sec. At count 8192 stage 14 goes high resetting 4060 & triggering 555. Note, .01 uF cap is not needed as soon as 14 goes high, 4060 is reset giving 555 a really short neg pulse.View attachment 80650
A 555 can be used for a 2 hour clock but a verry low leakage cap. is needed. I have gone to 3 hours.

Bernard as i can suppose, once the 4060 trigge the 555, it reset to 0 and start count 2 hours again to retrigger?, if that´s true then this is what i need, cheers.

 

I had assumed that it was a daily operation & yes it starts over after 12 hr. Other than Rx, the other resistors are non critical, anything in the 10 k region.
Adding caps from +9 V to 0 V, 10 uF & .1 uF would be good practice.

 

Two CD4060's in series gets you 28 divider stages and a built-in crystal oscillator circuit. Start with a 32.768 watch crystal. The final output is 1/8192 Hz. This works out to a cycle period of 2 hours 16.5 minutes. Not bad for crystal controlled and no adjustments.

ak

 

I had assumed that it was a daily operation & yes it starts over after 12 hr. Other than Rx, the other resistors are non critical, anything in the 10 k region.
Adding caps from +9 V to 0 V, 10 uF & .1 uF would be good practice.

this is a 2 hour cycle daytime, i meant every 2 hour y has to triger the 555 how could i do that with the 4060? wich i finally found.

 

T

Hi guys, i just rescently checked the posted thread trying to find a way to make this project, but too complicated solutions for a simple yet easy task, a timer triggering an event every 2 hours in this case, i need to move an AC motor through a 6/12V relay for about 6sec, it is s imple egg tray turner in a small incubator, so i´ve allready desing the motor time controled relay, but i need the trigger to activate that circuit every 2 hour, i guess the 555 can do the job but if any of you have any easy idea please let me know.

here is the actual motor relay cotroler 6sec (programmable), allready done, now i need to replace the actual switch with a time trigger, any sugestion? cheers.

View attachment 80646

to be more precise it has to trigger every 2hour the whole day time, remember it is a egg tray roller and every 2 hours the eggs have to be rolled.

 

to be more precise it has to trigger every 2hour the whole day time, remember it is a egg tray roller and every 2 hours the eggs have to be rolled.

The circuit in Post #6 has the 2 hour output signal going to the Reset input, which will restart the 2 hour cycle.

 

Sorry the 12 hr, post # 13, is suposed to be 2 hr; that is what the 4060 is setup for.
Modification shown increases reset time to about 6 sec.
Setting 2 hr with a 1 M pot, Rx, is trickey but gives a first approximation, ahter measuring pot replace with smaller value pot, say 20 k multi turn & pad remainder with standard values . Assume that 880 k is closest measured value & a 20 k pot. is available, then use 1/2 of pot value,10 k, add a 820 k & 51 k = 880 k. Other combinstions OK.
Surplus parts again-- R2 & C1 are not needed, bypass R2 & remove, remove C1.

 

Sorry the 12 hr, post # 13, is suposed to be 2 hr; that is what the 4060 is setup for.
Modification shown increases reset time to about 6 sec.
Setting 2 hr with a 1 M pot, Rx, is trickey but gives a first approximation, ahter measuring pot replace with smaller value pot, say 20 k multi turn & pad remainder with standard values . Assume that 880 k is closestView attachment 80675 measured value & a 20 k pot. is available, then use 1/2 of pot value,10 k, add a 820 k & 51 k = 880 k. Other combinstions OK.
Surplus parts again-- R2 & C1 are not needed, bypass R2 & remove, remove C1.

Yes that´s it, i don´t need any switch, this have to be like a perpetual 2hours operation so it will never stop until i decide off the device. i´ll test everything and let you know the result, i´ll play with R values in the range, Thanks again Sir Bernard for your kindly attention.

 

The circuit in Post #6 has the 2 hour output signal going to the Reset input, which will restart the 2 hour cycle.

Yes i know that´s a very nice adjustable circuit, but the only thing i don´t need is to push any switch, it has to be done perpetual, it has to reset itself every 2hr cycle, any way i will test every option and take the best situation that fit the needs, thanks for your attntion Sir.