This kit came very close to what I wanted to do: http://www.apogeekits.com/pulse_pause_timer_electronic_kit_mk188.htm
Unfortunately the accuracy of the 10 Min interval was more like 10min 15 secs + the 4s pulse. After 6 cycles overall time was closes to 62 min. Anybody have any idea as to how to alter that circuit so that the timing would be more accurate?
I started thinking that if I could hack an alarm clock to drive appropriate and gates when all the segments off a 0 where on.... but then I get stuck with the problem that I only want a 4-5s pulse.
From a square wave with 60s H, 540s L, 60s H, 540s L, etc. I would like to be able to drive a transistor for about 4 seconds on the leading edge that would activate a relay.
With the need of it having high fidelity to when a clock minute ones digit is 0.
Essentially triggering the relay @ 7:50, 8:00, 8:10, 8:20, 8:30, 8:40, 8:50, 9:00
any input is greatly appreciated.
Thank you,
Tim
Unfortunately the accuracy of the 10 Min interval was more like 10min 15 secs + the 4s pulse. After 6 cycles overall time was closes to 62 min. Anybody have any idea as to how to alter that circuit so that the timing would be more accurate?
I started thinking that if I could hack an alarm clock to drive appropriate and gates when all the segments off a 0 where on.... but then I get stuck with the problem that I only want a 4-5s pulse.
From a square wave with 60s H, 540s L, 60s H, 540s L, etc. I would like to be able to drive a transistor for about 4 seconds on the leading edge that would activate a relay.
With the need of it having high fidelity to when a clock minute ones digit is 0.
Essentially triggering the relay @ 7:50, 8:00, 8:10, 8:20, 8:30, 8:40, 8:50, 9:00
any input is greatly appreciated.
Thank you,
Tim