Lionel Banjo Signal

For the 1034 transformer, "U" goes to the center rail Lockon clip 1, "A" to outside rails Lockon clip 2.
One wire from the banjo to your insulated rail, the other wire to "B" for 6 volts or "C" for 20 volts.

Alternately, for lower track voltage(14 volts max), "U" goes to the center rail Lockon clip 1, "B" to outside rails Lockon clip 2.
One wire from the banjo to your insulated rail, the other wire to "C" for 14 volts.

If you need the full 10-20 volts for the train, use a pressure plate 145c and the 14 volts B-C post combination for the banjo.

There are actually other transformers better suited for insulated rail operation of accessories like the 140 Banjo Signal. Here are some examples.

Can I just attach 2 wires from this small transformer directly to the bottom of my Lionel Banjo Signal without having to do anything else.

Just need to know if possible, which connectors to attach to

Larry

No because you need the pressure plate or an insulated rail to turn it on/off.

Edit: The answer is still no if he wants the train to activate it.

@My Lionel posted:

Can I just attach 2 wires from this small transformer directly to the bottom of my Lionel Banjo Signal without having to do anything else.

Yes, as long as you accept the fact you will have to plug in the transformer to turn on the banjo, then unplug it to turn it off.

The quick answer is: YES. Any electrical device can be connected to its supply directly. YES, this applies to toy train accessories. YES it's your layout, wire it anyway you want.

Now, let's drill down a little deeper:  I have no idea if the banjo signal is electrically and mechanically robust enough to operate continuously. Its coil, motor, vibrator, whatever, may not like being energized all the time.  Only you can answer that question, as you experiment with voltage and time (what we call its "duty cycle.")

Finally, I would recommend that you put a switch in the circuit, somewhere, just so that if you do want to turn it on and off quickly and efficiently, you have that option.

Wire the banjo to the A-U posts and adjust the voltage for optimum operation. That means not too little, and not too much. Make a note of the voltage after measuring with your voltmeter, so that you can re-create the proper supply voltage in the future.

Arthur's answer above is a polite way of saying you might not want to do what you propose because wiring the accessory directly to power (certainly one designed to work only when a train passes) will probably lead to its early demise.  But, if you just want to see it operate continuously, attach one wire to the "U" post and another wire to the "C" post.  Then, every time you plug in and turn that transformer on by moving the black handle, the signal should start, and remain, operating.

Chuck