I want to lock my dog in his pen until I get out of the driveway so he won't chase my car.
I was thinking a retracting solenoid could be used to hold the (spring-loaded) door shut until it was activated, whence the dog to the cage would "spring" open and he could roam about at will.
It appears that I need a timing circuit such that I could energize it with the push of a button, then leave. When the set time (30 minutes would be max - 15 Min would be OK) had expired, I would need the circuit to close a relay so I could energize the PULL solenoid to release the latch and open the cage door, then shut itself (the circuit) off. No use using power once the door's open and the dog is gone.
I've found a Long Term Timer in one of my books [Rudolf Graf Electronic Circuits V2], but it requires manual switching to power things down. And was not detailed enough for me to follow - assumed [I had an] E.E. Degree I think.
I'm not the E.E. some of you are and would need sources/circuits with sufficient explanations attached so I would know which capacitor value or resistor value to vary to control the time, etc.
I have the MECHANICS down. I just need a way to time and power the solenoid.
6VDC would be GREAT (4 "D" Cells) as I would like the entire affair to fit on the cage in a small container that I could remove as necessary and not need to wire to the mains. But, I could live with a Wall Wart powered setup easily enough and have some 12vdc-13VDC Wal-Warts on hand.
Thanks for reading.
Charles
I was thinking a retracting solenoid could be used to hold the (spring-loaded) door shut until it was activated, whence the dog to the cage would "spring" open and he could roam about at will.
It appears that I need a timing circuit such that I could energize it with the push of a button, then leave. When the set time (30 minutes would be max - 15 Min would be OK) had expired, I would need the circuit to close a relay so I could energize the PULL solenoid to release the latch and open the cage door, then shut itself (the circuit) off. No use using power once the door's open and the dog is gone.
I've found a Long Term Timer in one of my books [Rudolf Graf Electronic Circuits V2], but it requires manual switching to power things down. And was not detailed enough for me to follow - assumed [I had an] E.E. Degree I think.
I'm not the E.E. some of you are and would need sources/circuits with sufficient explanations attached so I would know which capacitor value or resistor value to vary to control the time, etc.
I have the MECHANICS down. I just need a way to time and power the solenoid.
6VDC would be GREAT (4 "D" Cells) as I would like the entire affair to fit on the cage in a small container that I could remove as necessary and not need to wire to the mains. But, I could live with a Wall Wart powered setup easily enough and have some 12vdc-13VDC Wal-Warts on hand.
Thanks for reading.
Charles