FINALLY GOT BLUNAMI OPERATING COUPLER

Great work @BOB WALKER.

I see you are using the Blunami 2200.  I wonder if I use the 4408 and set the FX to a momentary button if I would need the relay or if I could do it direct?  I'd be using an MTH PS3 coupler which needs 5V to fire.

Ron

@Ron045 posted:

Great work @BOB WALKER.

I see you are using the Blunami 2200.  I wonder if I use the 4408 and set the FX to a momentary button if I would need the relay or if I could do it direct?  I'd be using an MTH PS3 coupler which needs 5V to fire.

Ron

Couplers draw much more than 100ma so you still need a relay. PS3 couplers are even lower resistance than Lionel or PS1 couplers.

You can also change the FX3 CV to the coupler CV to get the clank when you hit coupler.

Pete

So can I assume you need one per each coupler or can both couplers use one relay since only one is fired at a time?

If you want to operate one at a time you need two Function outputs and two relays. Consider the Blunami can supply 100ma @ 12-14v and the coupler is 5-8 ohms (PS2 or Lionel). That equates to 2 to 3 amps.
Bob, what are you using for relay power?

Pete

@Norton posted:

Consider the Blunami can supply 100ma @ 12-14v and the coupler is 5-8 ohms (PS2 or Lionel). That equates to 2 to 3 amps.

PS/2 and PS/3 couplers are 2-3 ohms, PS/1 and TMCC couplers are the ones that are 6-8 ohms and run on track power.

For coupler power I used the Blunami primary power source fed to the coupler via the NO contacts on the relay. The DIP relay has a 300ohm coil and is well within range of the FX current capability. For front and rear couplers, two relays and two FX's would be required. I wired up only the rear coupler initially, but almost never use the front coupler remotely, so may not get to it. I doubt that the Blunami could handle the coupler currents directly and don't want overload one. The relay approach is quite simple and is probably the best way to go.

John, I realize this is an old thread but is the track voltage converted to DC to actuate those PS1 and TMCC couplers?  I have several Atlas TMCC engines that I plan on converting to Blunami with the 4408 board.  I found some inexpensive relays to use that operate at 12 volts and use very little current that should work very well with the Blunami board.  I had planned on converting the Atlas engines to PS3 but changing the couplers is a pain.  Another quick question, is the PS3 5V supply for the couplers AC or DC?  Thanks.

Larry

You can fire a coupler with AC. PS1 couplers have essentially the same impedance as TMCC couplers. I use straight track voltage. The pulse is so fast it won’t damage the coil. Just make sure you have the Fx output set to momentary, otherwise the voltage will be applied continuously and burn the coil out.

Pete

Thanks, Pete.

Larry