Hello,
I am building a timmer control for an irrigator and need to control a latching solinoid. I am using latching as the system must be powered by batteries (and I am trying to avoid the additional cost of solar).
I have many times created simple switched control of the solinoids that require a short pulse + - to latch and a short pulse - + to delatch using a 2200uf capacitor in series to one of the lines and a SPDT to charge (create latching pulse) and discharge (create delatching pulse). I could simply use a SPDT relay to activate the solinoid but am trying to keep the current consumption down.
The attached pdf shows the SPDT switch that works fine. The other diagrams shows a transistor arrangement I thought would work but does not. The NPN is a BC547 and the PNP is a BC556. I am no electronics expert and really a novice, but this transistor circuit does not appear to be creating enough pulse as the solinoid only makes a dull thud noise and does not latch, even though the capacitor is charged.
Would some sort of N and P Mosfet arrangement work better possibly?
Any suggestions would be much appreciated.
Regards Blair
I am building a timmer control for an irrigator and need to control a latching solinoid. I am using latching as the system must be powered by batteries (and I am trying to avoid the additional cost of solar).
I have many times created simple switched control of the solinoids that require a short pulse + - to latch and a short pulse - + to delatch using a 2200uf capacitor in series to one of the lines and a SPDT to charge (create latching pulse) and discharge (create delatching pulse). I could simply use a SPDT relay to activate the solinoid but am trying to keep the current consumption down.
The attached pdf shows the SPDT switch that works fine. The other diagrams shows a transistor arrangement I thought would work but does not. The NPN is a BC547 and the PNP is a BC556. I am no electronics expert and really a novice, but this transistor circuit does not appear to be creating enough pulse as the solinoid only makes a dull thud noise and does not latch, even though the capacitor is charged.
Would some sort of N and P Mosfet arrangement work better possibly?
Any suggestions would be much appreciated.
Regards Blair