N0VUSUN and Mitsubishi-D700-SC

Can I ask you to confirm a couple of things that I've read/interpreted/misinterpreted...

1) When measuring the voltage on the relay you're looking at the side connected to the NVEM? And what you said in the last post was that when "on" the voltage here - at the NVEM side of the relay (pin 13 on the relay) is 24V? The relay LED is ON (dim)?

2) When the spindle is intended to be "off", if you measured the relay (pin 13) voltage it is 24V? The relay LED is OFF?

3) When you connect the NVEM output from to the relay (pin 13) to 0V the relay switches, and the relay LED is ON (bright)?

These first two appear contradictory to me - the side of the relay connected to the NVEM must drop by the forward voltage of the LED for it to light up - even dimly. I might expect the NVEM side of the relay coil to be 24V when OFF, but somewhere less than 22V when ON (a red LED is typically around 2V forward voltage drop). If you can confirm this behaviour then I can solve your problem. But if you're saying that the LED comes on (dimly) for condition (1) and off for condition (2) without the voltage on that side of the coil changing then I cannot understand the physics at play.

If you confirm that the voltage on pin 13 of the relay drops at least a couple of volts when the relay is supposed to be "on" then I'll get something in the post for you tomorrow to fix it.

Here's a good one for you.!

In the past I've had these relays come the wrong way around ie: Pin13 iss V+ 14 V- and it did exactly what you are getting. Check it.!

Quote:

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Originally Posted by JAZZCNC

Here's a good one for you.!

In the past I've had these relays come the wrong way around ie: Pin13 iss V+ 14 V- and it did exactly what you are getting. Check it.!

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I'm surprised. But, if OP is to test this then remember to swap the diode as well (so that the cathode is ALWAYS connected to +24V), otherwise you'll potentially damage the NVEM.

Attachment 27844
So does the relay and the diode look correct...

the 24v live to the relay is constant direct from the power supply if i test from 0v on the power supply.
i have 0v across pin 13 and 14 and then 24v across pin 13 and 14 when the spindle is turned on but only when the relay is pulled out.... it i put the relay in and test i only get 2 or 3v

just to confirm...on the relay is pin 13 to be 24v or 0v

Thanks. The diode is correct.

I've not been clear enough in how to measure the voltage, but the bit that you've said that you get 2-3 volts across the relay when the spindle should be on... that means you're dropping 3 volts across the relay coil which at 650R (roughly what it should be, given Jazz's quote of 36mA draw current) gives a switching current of around 4.5mA - bottom end of the performance of the opto-isolator of the NVEM and certainly not enough to actuate the relay.

If you are prepared to PM me your address I'll pop a gadget in the post (it's just the PNP transistor set-up... but I'll test it works before posting). Or, if you're happy to source/wire one up yourself then go for it.

Hi Doddy, i will pm you
Dave

Quote:

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Originally Posted by JAZZCNC

Here's a good one for you.!

In the past I've had these relays come the wrong way around ie: Pin13 iss V+ 14 V- and it did exactly what you are getting. Check it.!

---

hi jazzcnc
tried it round the other way including changing the diode round but still has the same effect, just dont think the controller has the ummph to switch the relay in

Dave,

Can't share images via PM so posting here...

Attachment 27931

hi
a massive thanks for your support...:beer:

...let's see if you're working first