Trigger Master MOSFET Fire Control System Discussion Thread

[DonP]

Since the For Sale thread for the Trigger Master is getting cluttered, I hope people will use this thread for discussion related to it instead.

Link to basic product info and support for the Trigger Master.

This first post will always be updated with news.

NEWS:
- Trigger Master Mark II released! New features!
- Example wiring for dual trigger setups added
- New model available: Sniper Special (enforces a max rate-of-fire of 1 round per second).
- YouTube Video Demo: YouTube - Trigger Master Demo Video

[The Saint]

Is there any internal space issue with rear wired version 2 boxes? Since one would be running 2 strands of at least 14 AWG to the motor, plus the 2 TM control wires.

[Roughneck]

Love the 30 round mag mod.. That should keep the milsim guys happy without having to carry an ass load of 70 round mags with only 30 rounds in them.

[CDN_Stalker]

Originally Posted by The Saint

Is there any internal space issue with rear wired version 2 boxes? Since one would be running 2 strands of at least 14 AWG to the motor, plus the 2 TM control wires.

A pair od #16 gauge wire and a pair of #24 gauge too. Really, one can't say much about front or rear wired mechboxes, it all barrels down, ease of installation or impossible, it's all about:

1/ Where you can find room to store the circuit board. They are about 2" long by 3/4" wide by 1/2" tall.

2/ Where the battery is installed. An M16 with a full stock is easy, but an M4 with the battery in a battery bag on the stock would be more difficult.

3/ How to run the wires so they are out of the way of normal gun operation (retractable stock, etc.) and to make it relatively simple to remove the mechbox to work on interally.

It's not by any means an easy install, even the easiest ones do require some thought. I found that with the rear mounted board and battery (M16 full stock), I ran the motor wires through the mechbox grooves to the motor, but the #24 wires I actually ran under the selector plate (outside of the mechbox, because the red #16 plus two #24 was too much bulk to run safely under the motor gear) into an unused hole in the mechbox just behind the trigger. Worked out very well without much of a headache.

[Splashx]

as for my G3, the fixed stock (rear wired) was just perfect for the trigger master. There's a small funnel at the bottom inside the stock that house very well the wiring and the chip (appart of the the battery compartment)

I'm enjoyed for the coding for the 30 rnd reloading enforcer. I gonna try it pretty soon, I just have to find a 4700ohms for the breadboard/isp connection :P Will a 5500ohms will be fine? I just opened yesterday my old 14" IBM screen and found very useful resistors, capacitors,...

[13Fido13]

Splashx, do you have any pictures of where it went, or how the procedure went. I'm thinking of putting one in my SG1 now that it's been upgraded enough.

[DonP]

[Installation is partly about] where you can find room to store the circuit board. They are about 2" long by 3/4" wide by 1/2" tall.

Note that the circuitboard is about the same size as most fuseholders, so it should at least be able to fit into the same space. (The Trigger Master can safely protect against an overcurrent condition, so you don't really need an AEG fuse anymore.)

Originally Posted by Splashx

I just have to find a 4700ohms for the breadboard/isp connection :P Will a 5500ohms will be fine?

5.5k should be fine. If you look up the spec sheet for the AVR ISP MKII programmer it tells you the acceptable value range for that resistor. Can't remember it offhand but 5.5k should be OK.

(Everyone: Splashx is talking about wiring up the circuit programmer for doing his own microcontroller programming. It is not something anyone needs to worry about or get into to install or use a Trigger Master!)

[Splashx]

Originally Posted by DonP

(Everyone: Splashx is talking about wiring up the circuit programmer for doing his own microcontroller programming. It is not something anyone needs to worry about or get into to install or use a Trigger Master!)

Yup, it's plug and play! Also needless to say the active breaking does it job perfectly! I don't feel anymore the "clunk" when the anti-reversal latch touch and stop the gears from running backward

[SEALs]

Hey don again for my GR-25, is it also programable to 20 rounds per mag?

[DonP]

Originally Posted by SEALs

Hey don again for my GR-25, is it also programable to 20 rounds per mag?

Short answer: YES.

Longer answer: The "30 rounds per mag" thing is an unofficial, do-it-yourself modification. But I'd be happy to help you with what you need if you want to buy one and set it up in your GR-25.

You will need:
- Trigger Master with custom programming for the 20 round mag mod (I can provide this.)
- Extra switch on the gun and wired into the Trigger Master; this switch needs to be CLOSED when a mag is inserted, and OPEN when no mag is inserted. You're on your own for installing an appropriate switch, though. (This is what senses the inserted magazine)

If you think you can swing that, I can hook you up!

[Splashx]

FINALLY! I had some weird problems with my programmer that sent me wrong wiring but yesterday, programming worked! Now, the only thing left is putting wiring for the switch find a good place for it.

I set my hardware programming bench for less than 5$ including everything?
How? I used a simple IDE wire plug (to connect a computer disc drive to motherboard), with a 4.6k resistor I've found in my old PC screen, 6 simple staples to plug the 6 pins programmer, 2x3 (6 pins) plastic alignment piece for the programmer (on my old video card), I used the electrical current +5V and ground for the power supply (that is in every PC's power connnector for drives)... And you're set.

This is not counting for the AVR USB programmer 39$ on DigiKey, a ATtiny85 3$, and a switch 1.50$. With all this, you're good to go with a 60$ budget. I'll post pictures when I'll have some spare time.

[gvanzeggelaar]

I just put one of these in my m14. I was using a 11.1v lipo battery and was melting my trigger contacts and was having other trigger issues relating to the CA m14. After I installed the Trigger Master it works like a charm. I recommend one of these to anyone with a G&G or an CA m14.

[Skladfin]

I've always wondered if these have the 1.2v voltage drop like other MOSFETS?

[gvanzeggelaar]

I couldn't tell you for sure, but my gun didnt appear to be cycling any slower

[DonP]

When a FET is turned on properly, there will be no voltage 'lost' across the FET while driving the load (well, virtually none if you want to be really picky).

That is not the case with "normal" transistors, which work differently and will have a voltage drop across the component itself like you mentioned.

Among other things it's one of the reasons why FETs are particularly awesome for electronically driving and controlling motors. (For example it's in all the even slightly-modern stuff for the RC crowd, and those guys take this stuff seriously :O )