Anyone with a LJ18A3-8-Z/BX using Ramps 1.4 board?

Ordered this one: [www.amazon.com]
Tested on my bench PS before installing, and at 5v the trigger light came on. As the other sensor wire was bundled up in wiring, I just spliced the new one on. Light triggers when I get it near my bed. However running an M119 command shows it as still OPEN.
Thoughts on how to correct this? It is wired directly onto the Ramps1.4 Z endstop like the LJ12A3 was.


Bench PS set to deliver 5.0v DC
LIGHT OFF ( NO METAL DETECTED )
Signal Line shows 5.03V
Bench PS shows 0.0A
LIGHT ON ( METAL DETECTED )
Signal Line shows 4.90V
Bench PS shows 0.3A

In contrast, the LJ12a34zbx under the same load shows 0.0A regardless if open or triggered, 4.90V if open, and 0.65V triggered.

While further testing, I thought perhaps it wouldn't work correct until I threw 12V at it. When I was testing, all of a sudden the Amps jumped up, and now the LJ18A3-8-Z/BX won't light up, and if I start to apply voltage to it, the Amps of the bench power supply go through the roof, with the voltage still low. Not sure why that is.

Bump hoping anyone can help here.

I have pretty much given up trying to understand these sensors. But there are ways to get them working. In the first example you might need to change your firmware settings. Assuming you're using marlin these are:
Z_min_endstop logic from true to false (or vice versa) and enable internal pull up resistors for Z_min_endstop.

There are obviously 4 combinations of settings, try them all and see if any combo gives you triggered when triggered and open when open.

As for the second problem I am told it's because there is no load on the sensor. So connect a small light bulb to the signal lead (or high OHM resistor/which is the equivalent of the internal pull up above) and measure again. They give spurious signals without a load.

---

Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Quote
DjDemonD
I have pretty much given up trying to understand these sensors. But there are ways to get them working. In the first example you might need to change your firmware settings. Assuming you're using marlin these are:
Z_min_endstop logic from true to false (or vice versa) and enable internal pull up resistors for Z_min_endstop.

There are obviously 4 combinations of settings, try them all and see if any combo gives you triggered when triggered and open when open.

As for the second problem I am told it's because there is no load on the sensor. So connect a small light bulb to the signal lead (or high OHM resistor/which is the equivalent of the internal pull up above) and measure again. They give spurious signals without a load.

Yeah I had tried all the firmware settings, all it did was make the Z go opposite direction.

Did you wired right?
[www.google.com]

If you wired wrong, the sensor might be damaged.

Use a 12 volts power supply and the connect a 5 volts regulator to the (black) signal output.

Quote
ggherbaz
Did you wired right?
[www.google.com]

If you wired wrong, the sensor might be damaged.

Use a 12 volts power supply and the connect a 5 volts regulator to the (black) signal output.

Like I said, I had the 4mm version wired in already. All I did was splice the 8mm version on in it's place.