basic one shot circuit if anyone needs one

[snorkelman]

got a mate to knock this together for me on EWB thus far its not been built outside the EWB simulation but Im told its working ok on there

 

select fire (selecting auto switches out a chunk of the circuit and hits the solenoid directly for as long as the trigger is pulled, selecting semi sends the solenoid a pretimed high that drops low again regardless of wether the trigger is still being pulled and resets on release of the trigger).

 

if anyone has a use for it feel free to help yourself

 

 

full res version here:

 

http://i33.photobucket.com/albums/d81/snor...101/oneshot.jpg

 

at moment its work in progress, personally Im looking to use it to control an old MMC full auto NBB mechanism where the standard push valve has been replaced with a gas soenoid Theres a couple of other things Id like to add to it for that application rather than rely on a pretimed output for semi, but I'll tackle those later once initial one is up and running.

[daddio]

Excellent - That is nice - especially when some countries can only use semi.

 

BUT WAIT - WE WANT MORE

 

Can your mate do even better- a tripple burst firing mode which replaces full auto!

 

Due to different rates of fire - you can't use a general pulse generator for a selected time frame triggering the solenoid (relay). However, a clever elecrtonics person (I've forgotten most my electronics since I became managment - sinful really) could have a feed back from the motor - sensing the current draw from the motor. When current reduces - no load - so spring must have been released - count one fire, then two, then three - finish cycle.

 

I know Systems Professional Training have some kind of circuitry that does this sort of thing - how is a mystery to me (I don't own one yet )- totally different gear box.

 

I'm sure many airsofters would love a cheap DYI burst mode kit. I know I would

[snorkelman]

ive got another one for him to work on at the moment again for a gas based system though different from above

 

it uses a fixed cylinder fed from a gas solenoid and uses a mechanical solenoid to operate a spring returned nozzle and load the BBs - we'd time that around time to activate mech solenoid and have a BB in the hop before gas solenoid is activated then pull high from the gas solenoid to shut off flow after Bb is fired and finish off firing cycle with mech solenoid being alowed to retract

 

In that system semi is a one shot while auto is just a repeat cycle of semi till trigger is released (most likely with an extra delay at end of a shot cycle to bring ROF down as it could get kinda funky)

 

it wouldnt be too hard to introduce a count into that to quit on three cycles rather than continue till reset on trigger release (to be on safe side Id have it conditional on a count of three or trigger release - that way it isnt rattling off three shots every time triggers pulled on burst)

 

AEG adds a bit of compexity to things cos as far as i can tell auto isnt really just a multiple repeat of semi (thanks to semi having cut off lever etc) and would need a different approach but I'll put it to him anyway see what he can come up with