dc42, 130uA is acceptable.

I don't have the parts on hand. Will give it a try as soon as I get them.

Thanks.

Telecommando, yes, I mean an on-off switch (to wires only). If that can be done, it will make my live much easier. I have no real background in circuit design (I'm a mechanical engineer), so I don't think I can come up with a solution myself

dc42,

What voltage are you using to pulse the solenoid? Do you know how much current it takes?

It's rated at 6VDC and 250ma.

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?

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.

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...

The solenoid take about 200-300ma to operate. The switching will be mostly slow (10-30 seconds apart) but sometimes, it should be able to operate at 1-5Hz.

This is the switch I use now. It is very low profile and is easy to push with your foot.




But currently, I use a normally closed solenoid which needs constant power to be kept open. So I have a large 7000mah battery or a 110/220 -> 12VDC power supply.

But the relay will consume power. I need the whole system to be battery operated get good battery life. So I can only tolerate power consumption when pulsing the solenoid.

Telecommando, if you have a similar magic solution with a 2-lead on-off switch, that would be great.

The only problem I have now is that I need a 2-state switch. The one I was going to use is a simple foot switch, 2 leads, on-off only...

works like a charm!

Telecommando, this will work?! I had in mind an Arduino and a couple of MOSFETs to do the switching... I like simple solutions. If this will work, that would be sweet!

But I don't see how this would give a "negative" pulse and I let go of the switch...

I need to build a circuit to control a latching solenoid. This type of solenoid will open when a short 6VDC pulse (under 100ms) is sent to it and will  closed when I reverse the polarity and send a "negative" pulse. I want to control it using a press-button: As long as I keep the button pressed, the solenoid is kept open. When I let go of the button, the solenoid will close.
This means that when I press the button I have to send ONE "positive" pulse and when I left go, I have to send ONE "negative" pulse.
Another requirement I have is that the whole circuit needs to consume no electricity when the button is not pressed. So I guess that when I let go of the switch, I need to keep the power connected for a couple hundreds milliseconds so that the circuit can send the  "negative" pulse to close the solenoid.

I know how to program the arduino really well but as for circuit design, I have no idea where to start... any help would be appreciated 

The original design is a 4.7uF tantalum cap in parallel with a 0.1uF ceramic cap...

The DTR and reset timing might be an issue. Although I did build the prototype and it works fine...

But they are used as filters.... what can go wrong if I use 1000pF instead of100000pF?