I built a small prototype circuit with a 9V battery and a 10V 3300uF capacitor. It works really well even at 2-3Hz switching.But as I said, I need a circuit with an on-off switch...
Also, I don't think there will be much of an inductive kick in this type of circuit so a flyback diode should be unnecessary.
What voltage are you using to pulse the solenoid? Do you know how much current it takes?
is the foot switch a momentary type (in which case, can you tolerate a small current draw while the foot switch is held down), or is it push on/push off?
Quote from: dc42 on Jun 15, 2013, 07:55 pmThere will be the usual large inductive kick-back when the upper contact opens, Inductive kickback from what exactly? When the capacitor is fully charged, there will be no current flowing in the coil. Opening the switch contact at that time will cause no arcing since there is no magnetic field being generated. You're likely thinking about a continuously held coil, which has current constantly flowing into it (and an associated magnetic field), but that's not the case here.
There will be the usual large inductive kick-back when the upper contact opens,
It's momentary type. As long as I keep it pressed, the circuit is closed. How small of a current draw do you suggest? A few micro amps is fine but if it's a few milli amps, that would greatly reduce battery life making this project not very practical.
have you ever heard of Gal? They make controllers and clocks for irrigation and pilot valves that are bi-stable latching solenoids. The method I used was to charge a 4700 uF cap to 12V and dump it into a solenoid with a DPDT relay and a Mosfet. The relay for polarity reversal and the Mosfet for switching the load. I could drive a solenoid through 300 meters of 16 Ga wire at 10 bars of pressure.