- #1
JO3
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Hello all,
I'm trying to make a circuit with the following properties:
1) output at +V for a time T1
2) output at 0 for a time T2
repeat indefinitely
**also, whenever contact is made between two points, I would like the circuit to jump to state 2 (contact would only be made when the system is in state 1)
It would be good if I can adjust T1 and T2 continuously, i.e. with a variable capacitor and/or potentiometer. T1 should be about 15 minutes and T2 should be about 45 minutes, but I want to understand the circuit enough to be able to make adjustments myself. Equations would be very helpful:)
I think I might be able to use the http://www.national.com/ds/LM/LM555.pdf" chip, but I'm not exactly sure how to set these up. Voltage should be between 5V-15V or so.
Thanks for your help,
Joe
I'm trying to make a circuit with the following properties:
1) output at +V for a time T1
2) output at 0 for a time T2
repeat indefinitely
**also, whenever contact is made between two points, I would like the circuit to jump to state 2 (contact would only be made when the system is in state 1)
It would be good if I can adjust T1 and T2 continuously, i.e. with a variable capacitor and/or potentiometer. T1 should be about 15 minutes and T2 should be about 45 minutes, but I want to understand the circuit enough to be able to make adjustments myself. Equations would be very helpful:)
I think I might be able to use the http://www.national.com/ds/LM/LM555.pdf" chip, but I'm not exactly sure how to set these up. Voltage should be between 5V-15V or so.
Thanks for your help,
Joe
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