so i have a bunch of solenoids. i tried hooking them up to power and flicking the switch on and off. i noticed that when i flicked the power switch off, the solenoid held it's position for a while before it released. I assumed this was useless for my purposes. BUT, then I recently started thinking it might make a difference when different frequencies are applied to the solenoid? does anyone know about this?

 

The flux in the circuit that is acctuating the contact does not just go away immidiatly. As the flux discharges, a reminant magnetic force keeps the contact pulled in for a moment after the control signal has been removed. That said...how big are these solinoids...it will take a pretty big coil to have a noticable delay or some weird mechanical property that could keep it pulled in.

 

it's this solenoid:
http://www.sciplus.com/singleItem.cfm/terms/15383

i've got a 12v bench supply powering it. i added a spring and a pin at the top to try making it bounce back faster, but it won't.

so the frequency doesn't make a difference?

 

relays are not switching components are slow as molasses and nasty gives spikes ionize the air if close enough it is after all a mechanical electrical device.

 

any thoughts on how these work so fast then?
http://www.youtube.com/watch?v=GW9bANKgTBU&feature=related

 

It looks like those are being driven by servos with pneumatic actuators, hence the description in the video...

"Pneumatic drums and guitar at the Maker Faire"

 

yeah, i got that.

how does a servo with a pneumatic actuator work?

 

A servo is really just a small motor. That motor drives a pump. The working fluid in the pump then drives whatever motion you want. Google it I am sure there are lots of good resources on hydraulic systems online.

 

Lots of interest in solenoids lately in AAC, lholze, Proj., kiel long Chat, jdm2008, Proj.,And123, Proj. One question, was your switch on powersupply or between pwr. & solenoid? SgtWookie not too long ago gave some references for snubbers which you would find usefull in speeding up solenoid turn-off.

 

it was the power supply switch, not something in between.

what is a snubber? i looked at schematics online, but most were meant to lengthen the life of relays.

are those all users with solenoid info?

 

After switching off power supply , there is a lot of charged capacitors to supply current to a load. When current to an inductor is interupted, the collapsing field generates a high voltage, 100's to 1000's. Placing a diode across the inductor, supplies a load to disipate the charge, which also slows down the release, in the case of a relay or solenoid. A snubber is a balancing act between speed and V spike. Adding some resistance in series with diode improves speed but does not completely eliminate V spike. Then use higher V switch[MOSFET].

 

All had something to do with solenoids, I think. Another post yesterday, seesoe ,Proj. ' Sense & triggrr later", gives reff. to a video on pneumatic control.