[dajt]

If that is the case I'd better unsolder the red and black wires! At the moment they connect 12v and GND. I'll check with the multimeter. It never occured to me they were the over-travel switch as the instructions clearly show power supply wires and electronics inside. Thanks for the hint.

[dajt]

I took the ETS off the mill and tested the two switch wires with no power "applied" to the ETS via the red and black wires. Using just a continuity test mode on my multimeter, the switch does seem to be a NC switch and it does not seem to require any power - the instructions imply there is some active electronics in there but there does not seem to be in my case.

I'll unsolder the wire I have going to the +12v pin and see if it still works on the machine soon.

I didn't get what I asked for, but perhaps a simple switch is good enough!

[Yurtman]

I'm looking at getting a similar Normally Open ETS. I'm a llittle confused with the spec for the output: 'Output specification: DC60V 100mA(resistance load)/ AC60V 100mA(peak)/ 500mW(Max)'

I thought the output was simply sinking the orange to ground, and for the overtravel protection simply opening the ordinarily closed green and blue. What's the 60V output all about?

[rdsi]

'Output specification: DC60V 100mA(resistance load)/ AC60V 100mA(peak)/ 500mW(Max)' What's the 60V output all about?

This sounds like the contact rating. Tormach uses 12VDC so you would be well within its spec.

[Yurtman]

The contact rating is 24V. Full specs here:

Model: CS-100K-50
Output mode: A: NO(normally open)
Stroke: 5mm

Contact life: 3 million times
Waterproof level: IP 67
Repeated positioning accuracy: 0.001mm(operation : 50-200mm/min)
Contact force: 1.5N
Contact material: Hard alloy, tungsten steel

Cutter ia.50mm, Height 110mm/4.3in

Surface treatment: Grinding 4S

Contact rate: DC24V 20mA(), recommend 10mA resistive load

Cable: Standard oil proof cable(6 cores)

LED light: Often off, on when working
Power supply voltage: DC24V
Consumption current: 10mA
Output specification: DC60V 100mA(resistance load)/ AC60V 100mA()/ 500mW()


Overtravel alarm signal:
Output mode B: NC is normally (emergency stop when the signal is disconnected)
Contact voltage DC24V 20mA resistance load (load required under special circumstances, current limit)

Weight: Approx.906g/32oz

[rdsi]

Yeah, mine has the same thing & I believe this is just the absolute max rating. Typical operation is 24VDC however it does work just fine at 12VDC - although the LED is not very bright.

[Yurtman]

It's odd that it seems to suggest 10-30V are acceptable for input, I can't see why it would have the contractor max at 60V, or why this would be described as output.

[Yurtman]

The specs are very confusing, the contactor is 20ma, but they advise a 10ma resistive load.....given that I have a 24v supply voltage are they suggesting a 2.4k resistor on the input?

[rdsi]

OK, there are a couple of things going on here.

There are ratings for 3 different things.

The device needs a power supply to work and this supply must be 10 to 30VDC. It is typically run at 24VDC and will draw 10mA to operate - 30mA at 30VDC. The Tormach DIN connector supplies 12VDC. You don't need a resistor here, you just need to supply a DC voltage between 10 & 30VDC. Obviously, it's not wise to run it at either extreme but some where in between - 12 or 24VDC is good.

The trigger output relay is really an NC electronic switch and is rated for 60V AC or DC with a max 100mA current rating. They are also saying you must limit the device power dissipation to 500mW. The Tormach DIN connector trigger input uses a 5VDC source in series with a 470 ohm resistor, LED (1.8V) and optoisolator (1.5V). So this switch must be able to switch this load to ground. No problem here because we are well under 60V and only switch about 5 * (5 - 1.8 - 1.5) / 470 = 18mW of power. All that is needed is to connect the wires between the output relay and the Tormach DIN connector trigger input and ground pins.

The over-travel NC relay is rated for 24DC @ 100mA. So don't use more than 24VDC & limit the current to 100mA through it. Most people don't use this relay but it might be a good idea to have it stop all motion. There is no way to do this through the Tormach DIN connector but one may be able to hook this in series with the limit switches common wire to effectively stop the machine.

[Yurtman]

Thanks RDSI, this is really helpful. Earlier in this thread it was suggested to put a resistor on the red 24v input to limit the current for the LED, is this unnecessary?

[rdsi]

Earlier in this thread it was suggested to put a resistor on the red 24v input to limit the current for the LED, is this unnecessary?

You can probably get away with putting one in but in my opinion it is unnecessary. The spec & diagram do not show one is necessary it just simply states 24VDC is the nominal requirement but you should be OK anywhere between 10V to 30VDC - all though I would not want to operate at either extreme. On the Tormach we use 12VDC so I'm comfortable with that. I believe when I had the device setup on the bench I operated it at both 12VDC and 24VDC to check operation. As I recall the only difference was the LED was a little dimmer at 12VDC than it was at 24VDC.

[Yurtman]

The spec does mention: Contact rate: DC24V 20mA(), recommend 10mA resistive load, doesn;t that suggest a resistor is advised? Or have I misunderstood.

[rdsi]

Contact rate: DC24V 20mA(), recommend 10mA resistive load, doesn;t that suggest a resistor is advised?

I'm not understanding where you want to put a resistor or why? The ETS can be hooked up as explained in this reply: Re: $100 China Made ETS's on Ebay ?? #32 without using any resistor.

I've explained everything I know about this ETS. I'm sorry I don't know how else to help you ...

[popspipes]

The spec does mention: Contact rate: DC24V 20mA(), recommend 10mA resistive load, doesn;t that suggest a resistor is advised? Or have I misunderstood.

That is referring to a resistive load, in other words the load is resistive, not an inductive load.

electric motor would be an inductive type load. (inductor/capacitor)
electric heater would be a resistive type load.

[Yurtman]

A reason I thought a resistor may be required on the input was to stop the LED burning out. Is it safe to assume there's an internal resistor in series to the led? Thanks for clarity on the resistive load vs inductive load.

[Yurtman]

Just a note to say thanks to RDSI and Popspipes for your input, my electronics knowledge is very bare so I appreciate your guidance.