gzus11 Posted June 27, 2009 Report Share Posted June 27, 2009 i thnink the circuit is pretty much the same for all active break, as it is a dc motor controll circuit discover circuits looks more complex than what is required for aeg. edn.com last page has an article on the circuit,i have built this one with the components specified previousl. as for rest state, i would not see any draw but it is possible if the fet diode leaked. but i would also suggest that any battery lipo especially, be disconnected when not in use. Link to post Share on other sites
infected Posted June 27, 2009 Report Share Posted June 27, 2009 but i would also suggest that any battery lipo especially, be disconnected when not in use. +1 Link to post Share on other sites
chownsy Posted June 27, 2009 Report Share Posted June 27, 2009 HELP! Just fitted a FET (Infected) to my AGM M14... The motor spins beautifully but the gears don't spin when it's connected back up. The gun just gives a 'click' when I pull the trigger! It was firing fine before I fitted the fet and all I have done to the gun itself is to solder the fet in place. I also tried spinning the gear I can see (when the motor is off) by hand and it doesn't seem to move. What's gone wrong? i have this problem with my M14 and its AB mossy (not infected one) Link to post Share on other sites
infected Posted June 27, 2009 Report Share Posted June 27, 2009 i have this problem with my M14 and its AB mossy (not infected one) What brand m14? Link to post Share on other sites
chownsy Posted June 27, 2009 Report Share Posted June 27, 2009 What brand m14? Agm m14 with m120 spring. Bearings. Guarder, tm and systema internals. Link to post Share on other sites
infected Posted June 27, 2009 Report Share Posted June 27, 2009 Agm m14 with m120 spring. Bearings. Guarder, tm and systema internals. I don't remember if that's built off the TM design, but I know that on the right side of the TM/CYMA gearbox there are two screws that hold the safety lever in place (I think). The two screws in it are different lengths. Swap them by accident and it'll pin the sector gear in place and keep it from turning. You might want to check that out. Link to post Share on other sites
Apex Posted July 6, 2009 Report Share Posted July 6, 2009 Fitted any to the Army R85 / GnG L85 series ? Infected, have you built any for the Army R85 / GnG L85 Series ? Link to post Share on other sites
hayabusa46 Posted July 14, 2009 Report Share Posted July 14, 2009 Can anyone confirem this, I will quote from magpul Picture Thread: make a cutout in a Magpul MIAD grip and put the cheetah in there. I believe Trichrome did this, I dunno if he was successful or not. The problem there is 1: the mass or wires 2: the heat generated by a motor like a magnum (GETs VERY HOT!!!). Is it posible to put a Cheetah mosfet in a MIAD grip, without damage the motor and mosfet in that time from the heat ? Link to post Share on other sites
muckymick Posted July 14, 2009 Report Share Posted July 14, 2009 Need a little help here.I have a tm psg 1 that i want to do away with the pre cocking mech on it and run it on a 11.1v lipo,i have changed the wiring and removed the lever that disengages the trigger contact's so now it works full auto.If i fit a mosfit with active bracking will this allow me to fire on semi or is their a mosfit that i could fit that would allow me to fire on semi? I really like this aeg but i hate the way tm made the thing work. Link to post Share on other sites
gzus11 Posted July 14, 2009 Report Share Posted July 14, 2009 you would need the cut off lever to keep semi auto fire. i dont know about the smart switch units but they would need some sensor to detect a single shot and cut out. Link to post Share on other sites
Captainkickass Posted July 20, 2009 Report Share Posted July 20, 2009 Hey i just built my mosfet and for some reason, when i plug in the battery it will automatically start shooting, its not that my trigger is stuck on the bridge, it just something up with the mosfet, i removed the mosfet and tried it with out, and it was fine. Am i not using the capacitors? Or is it the actual mosfet unit? Link to post Share on other sites
infected Posted July 20, 2009 Report Share Posted July 20, 2009 Hey i just built my mosfet and for some reason, when i plug in the battery it will automatically start shooting, its not that my trigger is stuck on the bridge, it just something up with the mosfet, i removed the mosfet and tried it with out, and it was fine. Am i not using the capacitors? Or is it the actual mosfet unit? Capacitors??? Sounds like either you have the wrong value resistor and toasted your gate, or possibly overheated and killed the p-channel fet. And there's also the possibility you have a short somewhere. can you give us a parts list of what you used? Link to post Share on other sites
sadigh Posted July 20, 2009 Report Share Posted July 20, 2009 Had the same problem. I just kept the battery plugged in, then pulled the trigger on semi, and the mosfet 'reset' itself (best way I can describe it) and the gun stopped firing. Next trigger pull fired as normal. I then opened up the gun to see what was wrong. Upon inspectation, the heatshrink I had insulated the solder joint on the bottom contact of the trigger switch had a slit in it, exposing the joint. This had caused a short, bridging the contacts of the trigger switch via the wall of the gearbox shell. The only thing that stopped it was the trigger itself, which nudged the wiring enough on the second (normal) trigger pull to break the connection, thus making the gun fire as normal. Take a look in your gearbox to ensure all the wiring is intact and that all connections are insulated Link to post Share on other sites
Captainkickass Posted July 21, 2009 Report Share Posted July 21, 2009 thinks infected for the quick response. Im using, a 100 OMH 2%, 1/4 Watt and a ..... 27K OMH 2%, 1/4 Watt With this mosfet http://www.alliedelec.com/Search/ProductDe...MPN=IRF1404ZPBF Link to post Share on other sites
masakarijoe Posted July 21, 2009 Report Share Posted July 21, 2009 i am planning on getting a Burst MOSFET. i want a Safe/Semi/Burst trigger group on my G&P M16A4. which brand Burst MOSFET is most highly recommended? thank you! -Joe Link to post Share on other sites
infected Posted July 21, 2009 Report Share Posted July 21, 2009 thinks infected for the quick response. Im using, a 100 OMH 2%, 1/4 Watt and a ..... 27K OMH 2%, 1/4 Watt With this mosfet http://www.alliedelec.com/Search/ProductDe...MPN=IRF1404ZPBF 27K Ohm is much much much higher than you really need. I'm guessing you're using just a MOSFET, not an active braking system. Do you have clear picture of the mosfet in question (not covered in heat shrink or anything)? Link to post Share on other sites
chownsy Posted July 21, 2009 Report Share Posted July 21, 2009 27K Ohm is much much much higher than you really need. I'm guessing you're using just a MOSFET, not an active braking system. Do you have clear picture of the mosfet in question (not covered in heat shrink or anything)? looking at the RDS(on) for the fet he is using datasheet for it it is far too high. most the ones ive been looking at are 0.2 not 2.7 Link to post Share on other sites
infected Posted July 21, 2009 Report Share Posted July 21, 2009 looking at the RDS(on) for the fet he is using datasheet for it it is far too high. most the ones ive been looking at are 0.2 not 2.7 Um, it's actually .00027 ohms..... that's perfectly fine. The 1404 from IRL was the defacto standard mosfet for a long while. The 27K ohm resistor is not a problem, but is way higher than it needs to be. I need to know from him if it's an active braking setup, or just a mosfet. If it's only got one fet, then it's just a mosfet. It sounds like a short or a fet that got overheated during the soldering process. Link to post Share on other sites
Captainkickass Posted July 21, 2009 Report Share Posted July 21, 2009 I'll get a picture up in a few hours. I was thinking it got over heated as well but 5 of them? I made 5 mosfets and same thing happened to all five. I'm just build a standard mosfet, no active breaking. I'll put up a picture in a bit. Link to post Share on other sites
infected Posted July 21, 2009 Report Share Posted July 21, 2009 I'll get a picture up in a few hours. I was thinking it got over heated as well but 5 of them? I made 5 mosfets and same thing happened to all five. I'm just build a standard mosfet, no active breaking. I'll put up a picture in a bit. If you're applying heat too long to the drain or source pin, that can very well happen. Or, you just made them wrong . Link to post Share on other sites
Captainkickass Posted July 21, 2009 Report Share Posted July 21, 2009 Heres a picture, i turned up the contrast and brightness so you can see as much detail as possible. Link to post Share on other sites
infected Posted July 21, 2009 Report Share Posted July 21, 2009 Try bending the resistor at the top so it's leads can't touch the tab on the mosfet and see what you get. If I had to guess though, they are toast. Link to post Share on other sites
chownsy Posted July 21, 2009 Report Share Posted July 21, 2009 that resistor reads 2.7K not 27K red = 2 purple = 7 red = 2 = number of 0's reading 2700ohm unless the 3rd ring is not red Link to post Share on other sites
Captainkickass Posted July 21, 2009 Report Share Posted July 21, 2009 its, red purple orange red, the packaging i got them from says 27k OHM Link to post Share on other sites
chownsy Posted July 21, 2009 Report Share Posted July 21, 2009 its, red purple orange red, the packaging i got them from says 27k OHM yea that is 27k, it looked red on the photo. 1st 2 colour band = number 3rd = number of 0's then you have 1 on its own that just an identifier ring that has nothing to do with the coding (this is the international colour code) Link to post Share on other sites
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