I'm looking to build a timer (it was suggested I look to use a 555) to turn on and off a load (which I will use an external relay driven by the timer). The on time will equal that of the off time. The time will be approximately 13 minutes.
I've done a bit of research on creating timers using the 555 chip and all the designs I found were to achieve cycle times in under 1 second. So, when I started to modify the values of the R & C to achieve 13 minutes I started getting some pretty large numbers. Then I found a software program called 555 Timer Pro. When I used to check my calculations the program warned me that the high resistor requirements needed to achieve t=13 minutes would result in too little current to drive pin 6.
So, now I'm out of my area of knowledge.
Can anyone suggest a design that would meet my needs here?
Thank you in advance.
Frank
I've done a bit of research on creating timers using the 555 chip and all the designs I found were to achieve cycle times in under 1 second. So, when I started to modify the values of the R & C to achieve 13 minutes I started getting some pretty large numbers. Then I found a software program called 555 Timer Pro. When I used to check my calculations the program warned me that the high resistor requirements needed to achieve t=13 minutes would result in too little current to drive pin 6.
So, now I'm out of my area of knowledge.
Can anyone suggest a design that would meet my needs here?
Thank you in advance.
Frank